If I’m understanding this right, grasslands currently store 0.2*450 Pg of carbon. That is 90 Pg of carbon. To absorb the outstanding 240 Pg of carbon, they would need to increase their carbon content 2.67 times – thus containing 330 Pg of carbon. That does certainly seem to be in miracle working territory.
Thanks for this much needed correction. I have seen many otherwise fairly intelligent people be swayed by this talk on various blogs.
People are too easily wowed by such claims and miss the orders of magnitude that he is off in his claims of how much C could be sequestered versus how much is both being produced and how much excess needs to be removed from the atmosphere. I do think that grasslands can and must play some role in sequestering carbon. But, as you point out, there is no one solution to this predicament (if ‘solution’ is even the right term for anything that is possible at this point.)
Another way of comparing the potential carbon-sequestration contribution of grasslands to the expanding scope of the problem is to consider just one source that threatens to add itself to the equation: thawing permafrost.
There is more carbon in permafrost than in all life forms, twice as much as is currently in the atmosphere, and it accounts for about half of all organic matter in all soils, iirc. So to hope that grasslands by themselves could offset even some of this one looming source for atmospheric carbon is clearly (and unfortunately) not realistic.
What should be obvious to all by now (but obviously isn’t) is that we have to stop making the increasingly impossible problem even worse.
That is we have to end all mining of any more coal, all pumping of any more oil, and all fracking (or otherwise extracting) of any more NG, and we have to stop all this massive UN-sequestration of otherwise-safely-buried carbon as quickly as possible if not much, much sooner.
But I see scant indication of movement in that direction.
I particularly liked your closing line:
“Humanity must look beyond hope and simple solutions if it is to successfully navigate its way through the Anthropocene.”
Mere hope won’t cut it. I actually would like to see people embrace what I would call “post-hope environmentalism.” Not meaning that we embrace despair.
But that we recognize that hoping for silver bullets to save us or even to avoid major negative consequences of our continued and increasingly idiotic and destructive behavior is not a useful or realistic strategy.
Doing what’s right is doing what’s right, whether we can have a reasonable hope that everything will be ‘alright’ in the end or not.
The ability to remain grimly determined even in the face of overwhelming odds and with little or no hope of success is a deeply rooted ethos in Anglo-Saxon (and many other) culture(s) that needs to be tapped again.
It was perhaps best expressed in the Old English poem, “The Battle at Maldon” by words set in the mouth of a member of a small retinue of warriors whose chief had been slain and who were in the process losing a battle against Vikings who were about to overwhelm them. He said:
hige sceal the heardra heorte the cenre
mod sceal the mare the ure maegen lytlath
It would actually be an even larger challenge than just to remove “now approximately 240 more Petagrams (Pg) of carbon in the atmosphere than in pre-industrial times.”
If we really do succeed in drawing down atmospheric CO2 concentrations, a maddening knock-on effect will be a reversal of the net flow of CO2 into the oceans. I.e. the ocean will become a net supplier of CO2 to the atmosphere… Sigh…
But yet another reason that grassland restoration, etc. is an insufficient (but necessary!) tool in the box…
Perhaps someone should buy him a subscription to ESD -oh, it’s open access – where we can read, for example, Becker et al., Lindeskog et al, or, in ESDD, Bowring et al., all of which might help illuminate the darkness…
Why is the whole article in italics? I kept wanting to get past the preface and into the body. [fixed the glitch -mike]
I always thought that plants absorbed carbon dioxide faster than we emitted it. I was convinced of this because the annual cycles in the Keeling curve are much larger than the smoothed growth is. Even though the ocean may absorb half of the carbon dioxide, I still find it hard to believe. (Not that this would the extravagant claims being made any more believable.)
Ah, the return of Allan Savory. What an unsavory development. I work for an agency that manages lands in the western US. Allan Savory first appeared in the 1980s with his “holistic management” which promised similar magic for western rangelands. Being a geologist this wasn’t my concern, but I’ve always been interested in larger land management issues so I paid attention.
Forgive me if these are stupid questions. I am not a climate scientist, or any other sort of scientist, but I am a mathematician with a scientific mind. I read this website to become more acquainted with the science of climate change (I’m also attending Prof. Archer’s Coursera class on climate change right now), and because this website seems trustworthy to me as someone who doesn’t know enough about climate science to decide for myself who’s right or wrong about this subject.
As I was reading this article, my questions struck me when I read “the amount of carbon in vegetation is currently estimated at around 450 Pg, most of that in the wood of trees.”
My questions are:
Would any amount of reforestation of deforested areas be capable of absorbing the excess 240 Pg since pre-industrial times? If so, approximately how many acres would need to be reforested? What level of annual carbon release by fossil fuel use would be low enough to reasonably “offset” it’s use with reforestation on an annual basis? Is there enough forest land surface on the planet to significantly reverse previous carbon release and leave some room for annual offsets? Are offsets even realistic solutions at all, or does the carbon just release back into the atmosphere when the trees die and decay?
Many of the things I read about climate change seem quite dire. The idea of reforestation, combined with the minor potential of Allan Savory’s methods, combined with who-knows-what-other carbon sequestration techniques, and finally combined with reduced emissions seems like a possible solution to me, (albeit one with little hope of implementation since it seems humans cannot get our s**t together), but I’m not smart enough to know if it is at all realistic scientifically, or just false hope.
Thanks to anyone who has any thoughts for me, on any or all of the answers. I know there’s probably a dissertation that could be written answering those questions, so I don’t expect much. (Unless of course there is already a dissertation that’s been written… then please refer me!)
That kind of question was once asked on another forum. This is the answer provided by Mark Cochrane, a climate scientist:
I had a 10 acre property that I would dearly love to have now. Had a spring fed pond and everything. I hand planted 700 trees there so I know very well the joys and back pain of such work! In the context of emissions, this is helpful but hardly a cure. Some perspective. While working in the Amazon, I decided to start running some calculations of just how important the deforestation problem and its converse (planting for carbon offets) were. I got out an envelope and started doing my proverbial calculations on the back (figurative witticism – actually I worked in a spreadsheet). I calculated the biomass (50% of biomass is carbon) of the entire Amazon (roughly 6 million square kilometers naturally forested (think 2/3 the U.S. including Alaska)), added in every bit of carbon I could come up with from leaf to root and all the soil carbon. I took the fossil fuel emissions levels of that period (1998) and divided it into the total carbon in the Amazon. I just couldn’t believe the numbers so I tried everything I could think of to correct them but kept coming up with the same numbers. So, I rang up one of the world’s leading experts on carbon emissions (who worked at the institution that employed me at the time – WHRC) and had him look over the numbers. Bottom line was that he agreed with my calculations. The take home message was that at that time (1998) the entire stock of Amazonian carbon equalled only 17 years of our collective fossil fuel emissions. I haven’t gone back to revisit those calculations since but the fossil fuel emissions have gone up substantially while the biomass of the Amazon has increased relatively slightly. I support Reduced Emissions through Deforestation and Degradation (REDD) but we are simply not going to be able to plant our way out of this. At 1998 rates, we’d have to somehow create new Amazon forests every 17 years to offset all emissions. Clearly impossible. Does this mean it is useless to plant trees, no! They have lots of uses and will help ameliorate carbon issues but they are not going to be a huge part of emissions reductions going forward. There are no silver bullets. We have a lot of hard decisions and harder work ahead of us.
While Savory’s obviously over optimistic, grasslands, depending on how they’re farmed, can be either a net carbon sink or emitter, ditto for forests.
The carbon isn’t being stored in the living plant matter, but in the soil, and the amount of carbon in 4″ of top soil (which is black because of that carbon) is going to be far greater than that in the plants growing in it.
Good posting, although to make the demonstration even more clear, it might have been great to summarize, at the end, by providing an estimated range of how much carbon sequestration can be realistically expected, assuming a hypothetical method that would allow for similar increases in carbon storage as is expected in Savory’s method (well, if he provides any numbers…)
I’m just puzzled by this: “Emphasis should be placed on climate change adaptation, rather than mitigation”
?? Is this really what you think?? Not only it seems misleading, but also it runs counter you call for “solutions in all sectors of society”.
[Response: We suggest an emphasis on adaptation over mitigation for grasslands in particular, especially where precipitation is relatively low, because they fluctuate annually between weak sources and sinks and the extensive management strategies applied have minimal effects on carbon balance. -Jason & David]
Thanks for posting this analysis. While there may be aspects of the Savory TED talk that have merit, I was puzzled by the claim that any grazing management system could somehow offset many decades of shuttling subterranean carbon into the atmosphere. It seems that the most we could hope to accomplish with grazing management is to return grasslands to their equilibrium state, with carbon levels at preindustrial levels in both the vegetation and the soil organic matter. I don’t see a agronomic technology in his talk that would exceed the carbon capture of preindustrial grasslands. So that still leaves 240 Pg of additional carbon to soak up somehow.
Grassland management may contribute to mitigation, but unfortunately, nowhere near the scale he suggests in his talk.
Savoury has been active in Australian agriculture for some time, although his influence has waned over recent years as many of his followers went broke. Most of his claims have been tested in rigourous independent trial work and found not to be true for temperate and subtropical pasture systems. These findings may not apply to the arid rangelands, but a long term trial in Queensland found it didn’t work in semi-arid rangelands. In short, he’s charismatic, but short on facts.
The criticism of rotational grazing is not so much that it doesn’t work but that it is not the only strategy for maintaining viable grasslands.
A later article by Briske among others notes:
“The scientific evidence refuting the ecological benefits of rotational grazing is robust, but also narrowly focused, because it derives from experiments that intentionally excluded these human variables. Consequently, the profession has attempted to answer a broad, complex question—whether or not managers should adopt rotational grazing—with necessarily narrow experimental research focused exclusively on ecological processes. The rotational grazing debate persists because the rangeland profession has not yet developed a management and research framework capable of incorporating both the social and biophysical components of complex adaptive systems.”
Origin, Persistence, and Resolution of the Rotational Grazing Debate: Integrating Human Dimensions Into Rangeland Research
The fact is that the maintenance and/or restoration of grasslands is a complex problem with a sociocultural components. In that sense, it is much like the problem of climate change itself.
Savory’s numbers may be wildly off but that doesn’t mean that restoration of grasslands in many areas of world would be of no benefit. It would certainly be of direct benefit to people living in those areas and would make perhaps a modest contribution to overall carbon problem. The same could also be said for reforestation efforts.
Since it does not seem likely that there will be ever a significant and deliberate effort to cut carbon emissions, it might be best to look for alternative solutions even if they solve only a part of the problem. Both grassland restoration and reforestation have good arguments in their favor besides whatever effect they might have on carbon sequestration.
Cattle that grazed according to Savory’s method needed expensive supplemental feed, became stressed and fatigued, and lost enough weight to compromise the profitability of their meat. And even though Savory’s Grazing Trials took place during a period of freakishly high rainfall, with rates exceeding the average by 24 percent overall, the authors contend that Savory’s method “failed to produce the marked improvement in grass cover claimed from its application.” The authors of the overview concluded exactly what mainstream ecologists have been concluding for 40 years: “No grazing system has yet shown the capacity to overcome the long-term effects of overstocking and/or drought on vegetation productivity.”
Deforestation would definitely help. Much of the reason that atmospheric CO2 levels have not risen faster is the uptake by plant life. Different species of trees have different rates of CO2 uptake, but generally faster growth requires greater quantities of CO2. This also varies throughout their life cycle. In theory, this is possible. In practice, it may not be that easy. Any reforestation would help, and the higher levels cause trees to grow faster, using more CO2.
I agree that Savory is part of the problem, not part of the solution. The accumulation of CO2 is clearly a consequence of widespread earnest confusion and self-delusion on these matters.
People need to be able to think quantitatively at the planetary level. The skill is not especially difficult or sophisticated but most people lack it, and some of them, like Savory, make prominent claims that others believe. People ought to be able to calculate at the “spherical cow” level.
But I’d appreciate some help lifting some confusion of my own on two points. The first is basically that mentioned by Greg Simpson in point 7; the seasonal flux in biomass seems to exceed the background rate of change of CO2 in the atmosphere by a large enough factor that it probably exceeds the total emissions. This doesn’t prove anything about the capacity of the biosphere to hold that carbon indefinitely, but doesn’t it at least prove, as SImpson says, that is is possible for the biosphere to absorb carbon at a more rapid instantaneous rate than we are currently emitting it?
The second is related. How much carbon can be stored in the biosphere? Growing woody trees will not be fast enough, but there is also the soil reservoir. How much carbon can be maintained in soil? How deep can the soil layer get? How quickly can we reverse the depletion of surface soils and how carbon-rich can we make them?
There’s a fellow by the name of Rattan Lal at Ohio State that comes up with optimistic answers to these questions. He is widely celebrated by the biochar community, but he seems to be practically alone in academia making these claims.
I haven’t encountered a serious response from the earth science community. If we set about manufacturing soil, rather than just encouraging cattle to do their thing, would we have a sequestration strategy that might have positive side effects? Or is this just another case of getting the numbers wrong at scale?
Some journals are beginning to put older work online in searchable form, e.g. this.
Belowground cycling of carbon in forests and pastures of eastern Amazonia
Global Biogeochemical Cycles
Volume 9, Issue 4, pages 515–528, December 1995
first made available online 21 SEP 2012
Short answer from that, apparently a study from the early years of converting the Amazon to beef cattle: deforestation converting forest to unmanaged, unfertilized grassland loses carbon storage; conversion to managed, fertilized grassland increases carbon storage — compared to the original forest on the site.
No mention of biodiversity or longterm stability; one can hope they revisited the sites 20 years later and will publish a followup.
Couldn’t he have simply been refering to “pre-industrial [temperature] levels”, instead of carbon levels? (implying a simple misidentification of what ‘levels’ we’re talking about)
After all, considering the math presented, if the soil/foliage carbon capture is tripled such that it eliminates the net carbon emission into the atmosphere, the natural component alone will eventually take us back to the pre-industrial range.
@Kyle & others. No genuine question like yours is a stupid question. It shows you can think for yourself. Adding to other responses as a non-scientist myself, circa 1992 the planet was destroying (clear felling alone) 3,000 acres of forests per hour (?) if my memory is accurate. Every hour every day every year. Since then it’s not got any slower, probably increased +/- year to year. So imagine the shift required to simply replace what “natural forests” have gone in the last 20 years alone @ 3,000 acres per hour, before one even begins to absorb an extra Kg of CO2 from the atmosphere. Luckily the Oceans are absorbing (is it) 90% of CO2 emissions already. Um, hang on, that’s another problem. The sheer scale of this “issue” is very hard, nay impossible, to get one’s head around. Mine hurts! :) [corrections welcomed]
So how does one get to be invited to do a TED talk then? I thought having a clue and making some significant contribution were requirements, not optimistically punting non-solutions to distract the masses from inevitable disaster if we do nothing.
As someone who has been vaguely a “fan” of Savory’s, I appreciate the reality check. (Me: not a scientist nor a cattle rancher, just one of those curious people out and about.) My comments only nibble at the edges, but anywho…
The first issue addressed in this post is that plausible carbon uptake could hardly keep pace with ongoing anthropogenic emissions. I don’t recall whether Savory said it in that particular TED talk, but I do recall him saying–either in writing or on a publicly posted video presentation–that addressing climate change requires a halt to the burning of fossil fuels. To treat his claims fairly, I think you need to use that as his starting point for what grassland sequestration could accomplish.
The post also points out soil moisture as a key factor affecting carbon uptake in grasslands. In Savory’s defense, much of his argument for his grazing method is specifically that it promotes retention of seasonal moisture in soils in arid grasslands. If he’s right (and yes, I noticed the link to research that he isn’t, but this is for sake of argument), then his method should, or at least plausible could, absent other mitigating factors, lead to increases in carbon storage in those grasslands–not necessarily at the scale he claimed on TED, but conceivably pointed in the right direction.
Finally, as I have understood the claims for holistic management, carbon sequestration occurs (to the extent that it in fact occurs) primarily in soils rather than in the biomass of the grasses themselves. Says http://www.nature.com/scitable/knowledge/library/soil-carbon-storage-84223790, soils hold 80 percent of the carbon in terrestrial ecosystems, and hold 3.1 times the quantity in the atmosphere. Granted, this doesn’t differentiate between forest soils and grassland soils (and any other categories). But it does suggest that the scales aren’t quite so off–framed this way, the question is whether it is plausible to convert that 3.1:1 ratio to something more like 3.5:1 (not calculated, merely a gut guestimation). Maybe still implausible… am I even right to think that this is a reasonable framing of the debate?
Comment by Jonathan Teller-Elsberg — 5 Nov 2013 @ 2:09 PM
Well, for change, it’s good to see someone too excited about some solution that does take up some carbon (even if a lot less than he says). Usually we see no will at all…
As a farmer, my observations are that:
Converting organic forest soils to pasture releases substantial carbon, the ground is dried in the process and the organic matter that had been pickled in the wet acidic subsurface environment starts to rot.
Well managed pastures on mineral soils will grow the amount of topsoil.
Well managed means:
fertilizer: promotes pasture growth, the more you grow, the more available fort soil sequestration, in appropriate temperate climates pastures will grow over a kg dry matter per m^2 a year, most of that dry matter is carbon.
rotational grazing: this promotes pasture growth, when grass grows from low initial cover it draws on root reserves to promote leaf, set stocking will result in cattle preferentially grazing this fresher leaf rather than the older, lower quality, leaf, this will slow pasture recovery and lower leaf production.
Avoiding compacting of the soil: water is stored in the voids between soil particles, compact the soil with trampling and the rain will increasingly runoff.
Your stocking rate has to be matched to the available feed supply, otherwise disaster awaits.
So to me a lot of what Savory’s saying is nonsense.
Seconding Hank Robert’s point at 30: “numerous studies have concluded that the replacement of older forests with younger forests results in a net release of C to the atmosphere…” Nunery, Jared S., and William S. Keeton. “Forest carbon storage in the northeastern United States: Net effects of harvesting frequency, post-harvest retention, and wood products.” Forest Ecology and Management 259.8 (2010): 1363-1375. Also look for work by Olga Krankina and Mark Harmon (both at Oregon State).
I am another non-scientist follower of RC, but I’m a long-time forest management policy analysis, and I immediately picked up that comment 21 is not based on any science I’m aware of. The only way to make clearing and “reforestation” of forests work to significantly sequester CO2 over time is to harvest without using fossil fuels (no chain saws! no mechanical yarding or hauling!), and then stack the logs without processing it at all. About as likely as the only real “solution” to global warming–stop burning carbon (fossil fuels).
Peal Oil can’t come soon enough, painful as it’s going to be.
The oceans take up about 90% of the excess heat that is the earth’s energy imbalance. They take up very roughly 50% of the CO2, not 90%. Of course, even with that proportion, the oceans are acidifying frighteningly quickly.
Whoops, I realised that my last post included an error. I said that the oceans took up, “very roughly 50%” of our CO2 emmissions. That is incorrect. The oceans take up the largest component but there are other CO2 sinks that, including the oceans, makes up the roughly 50% figure (actually a bit less, but it’s variable). I understand that oceans, themselves, take up about a third of our CO2 emmissions.
The comments on the permaculture hosting site are also helpful.
Comment by Brian Cartwright — 6 Nov 2013 @ 6:43 AM
#26 – Actually that critique is already linked to in the second paragraph of this post. It is a Slate article written by a professor of history.
Regarding various posts regarding converting forests into pasture, that has nothing to do with what Savory is proposing. Savory is about restoring plants and organic matter to soils that are depleted due to previous mismanagement- either over grazing or insufficient grazing.
I am not sure what Dan H meant. I thought he meant “reforestation” not “deforestation”. If he meant cutting down forest to create pasture, of course, that is a ridiculous proposal.
Savory is about management of relatively low rainfall areas that can support grasses but not forests or agriculture without irrigation.
Savory’s response to some criticism is that the comparisons between rotational grazing and continuous grazing that the study linked above does not actually study his holistic management method. The short duration rotational methods studied in experimental trials are, in fact, ones that Savory himself said would fail and are not his methods.
An article from a businessman and rancher who uses Savory’s methods explains this:
Unfortunately, the rangeland solution falls into the category of the single silver bullet theory which is a shame. There are a variety of agricultural and land management strategies that could play a small but useful role. But it is magical thinking to believe that any one strategy can save us from fossil fuels and the damage they are doing.
It’s easy after listening to Savory’s TED talk to agree, feel hopeful, and support the idea. It’s also easy to read RC, Slate, Briske, et al, and call Savory’s conclusions nonsense. Weigh each argument, check the notecards in your brain, find a few references,…. It may still be easy to draw a conclusion if Google leads you down one path or the other, or if you are predisposed…. I have ended up on the Savory path. Here’s why.
The math of soil carbon is that increasing soil organic matter by 1% means 0.58% carbon, but let’s consider 0.5% SOM. Determine bulk density or use a chart , e.g., http://www.sciencedirect.com/science/article/pii/S0016706111003247. Let’s use 80 lb/cuft. How deep is the soil measurement? Let’s use 6″. One acre = 43560 sqft, so 21780 x 80 x 0.29/100/2000 = 2.5 tons C/acre or X 3.67 = over 9 tons CO2/acre. Add subsoil increase and subtract CO2e for methane, and we have about 10 tons CO2 per acre in the soil. Topsoils can grow rapidly with good grazing, and there is a carbon subsoil profile as well. My five acre experiment with sheep doubled SOM from 1.5% to 3% in three years from seeding what used to be an Ohio soy field to pasture grazed two years, the second using a holistic grazing plan. The cost was about that of a down payment on a hybrid car, but had a much greater climate impact.
Consider that about a third of emissions are cycled into biomass and soil. ~12 GT CO2/yr are handled already. That leaves 24 GT. How many acres would it take at 10 tons CO2 per acre to have a positive impact. What percentage of the 12 bn non-forest arable land?
My first conclusion is that grass and grazing can be a rapid and massive mitigation tool.
There are many examples of restored landscapes. Water harvesting is one key. Sepp Holzer’s remarkable landscape restoration in Tamera, Extremadura, and elsewhere, creating waterscapes that maintain broadacre hydration, demonstrate this.
Grasses and animal impact can be another. Hooves break crusty soil allowing seasonal rains to penetrate, or they can create imprints that plant seeds, hold water, bend dead grasses and mulch them, allowing grasses to germinate and grow. This site has several examples of successes — http://www.ecoresults.org. Savory’s Africa Centre in Zimbabwe is another. Ian Mitchell-Inness is a highly successful HM rancher in South Africa. Greg Judy and Cody Holmes (who gets astounding soil carbon numbers btw) get great results in Missouri.
Pasture cropper Colin Seis plants annual grain in his sheep pastures, and gets the same yield as conventional at a fraction of the cost. The last report I heard was that his best numbers on his 2000 acres were above 30 tonnes CO2 sequestered per hectare per year. It’s a successful method. There are now 5000 pasture croppers in Australia.
My second conclusion is there are many successes that demonstrate the viability and potential of the method.
The third thing I look at is how it fits with respect to climate and planetary destabilization factors. CO2 emissions are only part of the issue. Carbon is part of a cycle, and good grazing management is part of that. There are two other facets. One is geophysics. Measure bare earth temperature on a sunny day, compared to grass or tree leaves. Higher temperatures mean more IR re-radiation, proportional to the absolute temperature to the fourth power. Yes, fourth power. Subtract albedo first, but this is still significant. More water is held in covered soil than bare. Trees transpire water and provide cloud and droplet nucleating compounds and microbes. The 540 cal/gram of evaporated water removed is released in the upper troposphere, where some of the heat released can be radiated into space = net cooling effect. More green can affect all of these factors which contribute to warming.
The other facet is that our earth problem is more than climate change. Extinction and desertification are majorly decreasing the livability of our planet. We need much more life to reverse this trend. Annual agriculture is destructive and consumptive. Perennial systems have many advantages here.
Conclusion — grasslands and forests are an important part of planetary stability. More is good.
Holistic management is a decision making framework. The tools, guidelines, and procedures used are up to the manager. Feedback may say that a method isn’t working. A water harvesting technique or grazing style may be damaging. Then work through the planning process again. Circumstances change, so adaptive management is key.
If there are successes and failures, and the successes are potentially positively earth changing, we need to look at why successes and why the failures, and work to increase the success rate, not dismiss the method out of hand. That hurts rather than helps. Visit some of the successes. Try your own experiments. This is a potential earth-changer.
The survival or human, and maybe all, life may depend on how well we manage. Let’s learn from this and apply it as broadly as possible. The ultimate success will depend on our willingness to earnestly pursue a path of regeneration of life and systems that sustain it.
Thanks Tony Weddle and everyone else for your responses. You’re helping my pea-brain wrap around the immensity of all of this. I know there is no silver bullet, but I’m wondering if a barrage of (metaphorical) lead ones (trees, grassland management, whatever other geoengineering project there is) all aimed at carbon emissions, might offer some hope. If only, right?
“If we were to capture 1 ton of carbon per acre per year on the roughly 5 billion hectares of grasslands worldwide, we would remove 12 Gt of C from the atmosphere per year, that is, 6 ppm annually. If gross soil sequestration were approximately 6 ppm/year, after subtracting current annual carbon emissions of 2.5 ppm/year net sequestration would be 3.5 ppm per year.”
I am trying to reconcile the 8 and 2.6 petagrams in the post with Savory’s numbers and with your 12 and 24 GT numbers.
I think you misunderstood Kyle’s original question (#10) and my following response (21). We are talking about harvesting forests as a means to increase carbon uptake. The question centered around the possibility of atmospheric CO2 removal by planting more trees. Check data on the Keeling curve. The seasonal CO2 decrease exceeds the annual increase. Image the change, if the numbers of trees doubled.
The existing anthropogenic excess of atmospheric CO2 is self-evidently already causing dangerous warming so we do need to draw it down to preindustrial levels as quickly as possible.
Savory’s proposal seems dubious but I have seen other studies which show that organic agriculture and reforestation can sequester large amounts of carbon in soils and biomass — and of course they have other benefits as well, for biodiversity and human health. So I think we should pursue those approaches as aggressively as possible.
However, carbon sequestration, by whatever means, should ABSOLUTELY NOT be regarded as a way to “offset” or “reduce” ongoing GHG emissions, or as an alternative to phasing out fossil fuels.
We still need to end ALL anthropogenic GHG emissions as soon as possible — AND we need to beging drawing down the excess CO2 that we have already put into the atmosphere.
Savory also ignores cattle methane. Consider Australia. We have more cattle than people and even more sheep. About 30 million cattle and 80 million sheep. They produce about 3 million tonnes of methane annually.
Using Shindell’s figure of the GWP of methane over a 20 year period of 105: https://www.sciencemag.org/content/326/5953/716
This makes 3mt of CH4 equal to 315 tonnes of CO2 over a 20 year period. In addition, the practicalities all over the planet are that its cheaper and easier to just knock down more trees when you want more pasture rather than muck around with labor intensive new methods. So in Australia our cattle producers have averaged about 69 million tonnes of CO2 from converting forests to grass every year since 1990 (National Inventory 2010, Vol 2, table 7.2). Taken together this is rather more than double the 169 million tonnes of CO2 coming from our coal fired power stations.
Geoff, I think your example may be misleading. Given the short life of methane, current emissions are at least partly replacing emissions from the previous decade that were subsequently reduced. As a result, a stable population of ruminants need not increase the stock of atmospheric methane over time (or the associating forcing). In contrast, the CO2 emissions emitted by a coal plant represents a cumulative contribution to the atmospheric stock of carbon.
Re- Comment by Geoff Russell — 6 Nov 2013 @ 4:46 PM
Where do you think that the methane from cows or sheep comes from? It comes from grass that removed the CO2 from the atmosphere for growth (I am not talking about CO2 from the use of fertilizer derived from fossil fuels). Methane only lasts a short time in the atmosphere (relative to CO2), and that from sheep burbs and cow pies are a wash because you have to subtract the carbon that was first removed from the atmosphere.
We can squabble about the order of magnitude, but with this strategy as well as other strategies, we may be able to bring the earth back to health. Why are we still giving subsidies to the fossil fuel industry? We don’t talk about this anymore. Big win for the industry! Why is industrial hemp still prohibited when we could be leaving trees to do their work and use hemp for paper (the yield is 4 times higher in one season than for trees in 10-15 years and no pesticides or dioxins are needed). We’re doing everything wrong because it still pays to dump poisons into the atmosphere. There is so much waste of energy it’s staggering but the public is not educated. The reason is because the fossil fuel industry does all it can to put that in the furthest parts of our mind. It’s a mind game that tries to keep everyone addicted. We may or may not be able to fulfill our energy needs with renewables but we’re not even trying to do it in a graduated way. We’re just not doing anything differently that how we’ve been doing things for the past 30 years.
We don’t know the earth’s propensity for healing. We haven’t tried or tested it on a large scale so we don’t know. We are not doing enough in ways that we can. Even if Allan Savoy’s method doesn’t sequester as much carbon as stated, holistic management in concert with conservation, using hemp and other stocks for replacing trees and petrochemicals, ramped up public transit systems plus educating the public to conserve makes the most sense and could very well save our sorry asses.
Thanks for that link, hank. I have a friend who is doing something similar (perhaps inspired by Phil? I’ll have to ask her).
I got so excited about the project that I went out and bought a big bag of hazelnuts. Unfortunately, it turns out I have allergies to them and ended up in the emergency room near death’s door. As with everything else, we need multiple such innovations to accommodate different needs.
Looks like RealClimate and a whole lot of posters missed the boat on this one. There is a fundamental problem with 90% of the Savory detractors comments, the carbon sequestration is NOT in the grass, it is in the soil. When grass gets grazed the plants shed roots in much the same way trees shed leaves in fall. This lignified carbon becomes food for a whole web of life in the soil and quickly gets reduced to stabilized humus. Unlike trees though, the humus is deep in the soil, not on top in the leaf mat. Also unlike trees, the grass plants can potentially shed this lignified carbon many times a year. The result is that it builds the soil fertility and nutrient/water holding capacity while sequestering far more carbon than is in the plant itself. It is all in understanding the grass plant and optimizing this trait with a good management system.
I am not sure exactly why Briske has such a block on the concept. He himself admits his conclusion “derives from experiments that intentionally excluded these human variables”. Savory is advocating Holistic management. Management is all about “human variables”. Management is the breakthrough, not the biophysical properties. The biophysical properties have been well known and proven for decades.
If Briske is not smart enough to set up a trial that includes these management variables, that’s on Briske, not Savory. Savory was able to set up a trial, and that trial won the prestigious Buckminster Fuller Award. Plenty of other scientists have confirmed the carbon sequestering biophysical properties of the grassland/grazer symbiosis are real too.
Cenozoic Expansion of Grasslands and Climatic Cooling http://blogs.uoregon.edu/gregr/files/2013/07/grasslandscooling-nhslkh.pdf
Grazing management impacts on vegetation, soil biota and soil chemical, physical and hydrological properties in tall grass prairie http://www.sciencedirect.com/science/article/pii/S0167880911000934
Pastures for profit: A guide to rotational grazing http://learningstore.uwex.edu/assets/pdfs/A3529.pdf
WINNER OF 2010 BUCKMINSTER FULLER CHALLENGE http://challenge.bfi.org/press/2010_winner
So before everyone starts jumping on the RealClimate/Briske bandwagon that failed, maybe reconsider that it might be better to go with the scientists that succeeded?
“Results? Why, man, I have gotten lots of results! If I find 10,000 ways something won’t work, I haven’t failed. I am not discouraged, because every wrong attempt discarded is often a step forward” Edison
John Kempf cites Horst Marschner — Mineral Nutrition of Higher Plants. Healthy plants exude 60-70% of their productivity to symbiotically feed microbes in the rhizosphere. This carbon induction is often the missing piece in the discussion about grazing effectiveness. I’ve been told that 4-5 tons of added carbon per acre per year is impossible. Well, according to Marschner, and based on hay yields, farmers who get 5 tons of forage in a season could be putting 20 tons of sugar in the soil, and some have even higher yields.
“A healthy plant will have at least as much root biomass below ground as there is plant biomass above ground. So if we have 100 pounds of plant biomass above ground, and an additional 100 pounds below ground, this still represents only 30 to 40 percent of this plant’s total energy production. This [carbon induction] is the real secret to building soil carbon effectively and efficiently. We can readily see why forage-based livestock agriculture and perennial polycultures are the most efficient method of building soil organic matter and stable humic substances. Carbon induction is the answer.”
“… forage-based livestock agriculture and perennial polycultures are the most efficient method of building soil organic matter and stable humic substances.”!!!
Let’s learn from the people that are making these “outlandish” claims.
I’ve been to field days and workshops with biological farmers, cover crop practitioners, holistic grazers, (who, to a person, intend to keep improving) and more often than not, someone will show up and claim he is doing better using this or that improvement. They get by with less inputs, have deeper soil, stock at higher rates, get higher yields. One guy in Ontario broke 300 bu/acre corn. Fantastic. Nobody else is doing that. It probably took him a couple decades to figure out how to do it. Don’t try to prove him wrong with one experiment! Some farmers whine that they tried his method and it didn’t work. No surprise. That’s farming. Some will keep trying, and some of those will succeed. A good decision framework like HM can only help.
There are successful HM practitioners around. If you can make it to Springfield, that’s the one on Illinois, you can meet a few of them at the Acres USA conference next month. And maybe talk to John Kempf, and a whole host of practitioners that are revolutionizing agriculture, … naturally. Find out how they do it, and support it, and do it, too.
Comments on Dot Earth – Revkin November 7, 2013
Far from being helpful, this post by Messrs. Briske and West on Real Climate is misleading – at best. Mr. Briske’s work is hardly the unassailable refutation of Holistic Management that he claims. Rather, it is largely irrelevant. While we should all be focusing on advancing towards a solution to the climate change crisis, which I discuss below, first and foremost, it is paramount that the record straight be set straight.
Briske’s own work makes it abundantly clear that his conclusions have no bearing on Mr. Savory’s work: “Experimental evidence indicates that grazing systems, in the absence of adaptive management, explain little additional variability beyond that of stocking rate and weather variation” regarding ecological factors (Briske et al., 2008, p. 57, available at http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1045796.pdf (emphasis added)).
The operative phrase here is “in the absence of adaptive management” – this qualification is not a trivial one. Anyone familiar with Mr. Savory’s work and the Holistic Management Principles is aware that monitoring and adaptive management responses is essential to Mr. Savory’s frame work. In fact, Holistic Management materials have referred to “plan” as a twenty-four letter word “plan-monitor-control-replan”. Therefore, the work by Mr. Briske and his colleagues – by its own admission – is irrelevant. No amount of grandstanding or brute repetition can cure these fundamental defects.
With respect to soil carbon in particular, Briske et al. correctly make realize that the work they have evaluated in inconclusive: “The response of SOC to stocking rate is equivocal, based partially on the limited number of investigations conducted” (Briske et al., 2008). My colleague, Seth Iztkan of Planet-TECH associates, provides an excellent analysis of the numerous other reasons that the work of Mr. Briske and other has no bearing on the proper implementation of Holistic Management (http://www.planet-tech.com/blog/regarding-holechek-savory) or its observed effectsw.
Second, when based on appropriate studies, rotational grazing has shown clear benefits. The work of Teague et al. – colleagues and prior coauthors of Mr. Briske – make clear what ranchers employing Mr. Savory’s methods have known for decades: “Our study contradicts a recent review of rangeland grazing studies (Briske et al., 2008) which suggested MP grazing does not improve vegetation or animal production relative to continuous grazing. The discrepancy is because we measured the impacts on vegetation and soils achieved by ranchers managing at the ranch scale and adapting management in response to changing circumstances in order to achieve desirable outcomes” (Teague, et al 2011 ( ISBN 978-1-60692-023-7)).
In sum, this post by Messrs. Briske and West is only the latest iteration in fundamentally flawed assessments of the impacts of grazing systems.
I assume, however, as Messrs. Briske and West profess, that we are all sincerely dedicated to finding solutions to the climate crisis. To these ends, Briske et al. themselves point to a way forward: greater integration of the results of actual ranch operations – including the management systems that are integral to actual performance – in evaluated studies. Along these lines, Teague et al. (2013) propose specific and testable hypotheses that grazing research could evaluate. Let us do that. Instead of continually bemoaning the limits of experimental data to date, let us base our claims on actual the results of actual ranch management operations. While perfection and absolute certainty are impossible – as every ecosystem is unique and undergoes changes from year to year – that is no excuse for complacency. There are numerous management operations that could be observed. This is just one way in which to move forward toward much needed solutions to the climate crisis.
1)seem to overlook the fact that many posters do aver that grassland sequestration has a role to play, as I do in post #4 “I do think that grasslands can and must play some role in sequestering carbon.” and
2) don’t even attempt to address the mathematically indisputable (as far as I can see) fact that grassland sequestration cannot come close to offsetting the current levels of carbon emissions, much less reduce the excess carbon already in the atmosphere (at least not while said emissions continue).
Having said that, I do think that there are misconceptions when people who don’t know about them hear that native grasses can act in this way. IIRC, 90-95% of the biomass of these grasses is underground, stretching over three meter deep into the ground, and wildly brachiating: a four month old sprig of grass will already have grown a root structure which, if segmented and laid end to end would measure 137 miles. And, as pointed out above, bits of it are constantly dying and turning into soil.
But for the prairie to play a major role in carbon sequestration, we would need to re-purpose vast swaths of the land that is now in use producing grain, this in a world that is about to face major shortages of food as population expands and GW bites ever deeper into yields. I’d love to see the rewilding of the plains and midwest, with buffalo grazing in profusion again. But there are many political obstacles and practical impediments to that ever coming about.
I am glad to see H.D. Silver use the term “solutions” in her final sentence, as this is a tacit admission that grassland alone can not ‘solve’ global warming. Perhaps this could provide a basis for common ground and useful discussion?
The tip-off was when Savory himself in the TED talk prefaced his statements by saying he wasn’t big into carbon budgets.
#53, I almost agree, but the rate of carbon storage versus the rate necessary to pull CO2 from the air is the critical factor. In Earth history, net soil carbon has accumulated at comparatively small quantities per year, which is why annual CO2 levels haven’t been constantly plummeting over the course of Earth’s history. I looked at the numbers based on IPCC tables for land types by area and carbon storage and plant vs soil carbon, and I conclude maybe 60 GtC could be sequestered in plant and maybe about 60 GtC in soil after some time of decades or longer. We can’t just shove carbon down the throat of the soil, so to speak. We should still pursue the suggestions though, even if it is 60 or 120 GtC, that’s nothing to laugh at. Here’s a bit more of my thinking on the Savory TED talk, if interested: http://www.fairfaxclimatewatch.com/blog/2013/03/savory-adds-an-arrow-to-the-climate-fighters-quiver.html
Exactly. That is why harvesting trees will have no effect on CO2 levels. Reforestation will sequester the CO2, removing it from the atmosphere. I have not seen any calculations as to how much this would reduce those levels.
wili wrote: “grassland sequestration cannot come close to offsetting the current levels of carbon emissions”
No method of sequestration, or combination of methods of sequestration, can come close to offsetting the current levels of carbon emissions.
To suggest that sequestration removes or lessens or postpones the need to end ALL anthropogenic GHG emissions as rapidly as possible is irresponsible and dangerous.
Given that the already existing anthropogenic excess of GHGs is already self-evidently dangerous, we need to draw it down to pre-industrial levels as rapidly as possible — and that’s where sequestration comes in. But that only has a chance to succeed IF we stop the ongoing emissions.
A world powered by solar and wind energy, and fed by organic agriculture, and devoted to protecting and healing damaged forests and other ecosystems, has a chance of survival.
Good point 2. What supporters of Savory’s method need to show is that the figures given in this post (8PgC added annually, versus 2.6PgC taken up by all earth vegetation annually). For a small fraction of the earth’s land surface to be able to sequester 8PgC, and climbing) annually seems hugely optimistic, at best. Unless the figures we’ve been given are very wrong.
Very high sequestration potentials for these strategies have been reported, but there has been no systematic analysis of the potential ecological limits to and environmental impacts of implementation at the scale relevant to climate change mitigation. In this analysis, we identified site-specific aspects of land, water, nutrients, and habitat that will affect local project-scale carbon sequestration and ecological impacts. Using this framework, we estimated global-scale land and resource requirements for BCDR, implemented at a rate of 1 Pg C y−1. We estimate that removing 1 Pg C y−1 via tropical afforestation would require at least 7 × 106 ha y−1 of land, 0.09 Tg y−1 of nitrogen, and 0.2 Tg y−1 of phosphorous, and would increase evapotranspiration from those lands by almost 50 %. Switchgrass BECS would require at least 2 × 108 ha of land (20 times U.S. area currently under bioethanol production) and 20 Tg y−1 of nitrogen (20 % of global fertilizer nitrogen production), consuming 4 × 1012 m3 y−1 of water. While BCDR promises some direct (climate) and ancillary (restoration, habitat protection) benefits, Pg C-scale implementation may be constrained by ecological factors, and may compromise the ultimate goals of climate change mitigation.
#48 & #50 … Anything which turns carbon dioxide into methane will increase the radiative forcing of the carbon atom considerably. Put a bunch of heaters into a room, now magically transform some of them from 1-bar heaters into 105 bar heaters. Will that have an impact? Of course. The fact that the heaters turn back into 1 bar heaters after 10 or so years does not mean that they won’t have any impact when they are on. It matters, of course, what the ratio of transformed to untransformed heaters is and that ratio has been rising for quite some time … i.e., there’s now more methane atoms per CO2 atom than there was 100 years ago.
The difference between turning carbon from grass into methane and carbon from coal into methane is miniscule compared to the impact of the methane while it is methane. A tonne of methane has 105 times the impact of a tonne of co2 over a twenty year period and if it came from grass carbon, it only has 104 times the impact.
A few posters have suggested that no amount of sequestering can come close to offsetting carbon emissions. Yet, as Ashley Ballantyne’s work shows, current vegetation levels are still soaking up about have the carbon emissions, even as emission rates have increased. It does seem that far fetched that Savory’s method has merit.
It’s great to be part of the RealClimate discussions here, including the discussion of soils, the carbon cycle, organic matter, etc. I think folks are grappling with the major issues and would point everyone to the Fifth Assessment Report from the IPCC, specifically Chapter 6 that deals with C and other biogeochemical cycling, lots of good info in there (http://www.ipcc.ch/report/ar5/wg1/#.UnzuCuIlJtU). We’ll try to continue to comment inline if we see appropriate places to do so!
What is bothering me about this discussion is that at about 19 minutes into the TED talk, Savory says what he proposes can help after we’ve stopped burning fossil carbon. Given that proviso, it is not all that unreasonable that a target of 280 ppm atmospheric carbon dioxide concentration could be achieved through land surface based sequestration. The action of the oceans alone bring us to 350 ppm within a couple centuries if we stop emissions now. Dropping another 70 ppm through land management practices is not out of the question at all. Biochar, irrigation of dessert land, crushing of serpentine silicate rock, even burying algae have been proposed at times as at least scalable possibilities. Revived grassland, if it works, is just another of these.
But the discussion here seems to have built up a strawman that he is claiming to capture ongoing emissions entirely. It just does not sound like he is making that claim in the talk.
Tony, and all –
The figures are close to the round numbers I use in general discussion, which come from NASA’s carbon cycle diagram. Those aren’t the only numbers to consider. So 9 Gt or Pg C emitted annually, 2 –> ocean and 3 –> biomass and soil. The remaining 4 account for the 2ppm CO2 annual increase in the atmosphere. 6 GtC is what the terrasphere doesn’t handle, and the amount that needs to be reduced to “stay even” more or less, though the ocean will then reduce atmospheric C until equilibrium is reached.
The other relevant number here is 123 GtC, the amount of annual carbon flux in the terrasphere. 3 GtC is only the net which is currently sequestered in new growth. This amount is actually astounding, considering the planetary ecosystem destruction being experienced. Stopping the damage reduces emissions. Reversing the damage increases the benefit.
6 GtC is less than 5% of total productivity, and 8 is 6.5%. Looking at it from the point of view of doubling or tripling the net or new growth makes it seem much more daunting than it is, which is actually still daunting. But it’s not impossible. A 6% increase in total flux. That’s a more realistic perspective. Any NEW growth is what helps. Soils and tropical forestry are rapid and massive sequesters. Savory’s method is indeed optimistic. There is a lot to overcome to be able to transition and restore enough land to turn things around. But it’s not impossible.
But Ag has to change. The sooner the better. Some estimate humans appropriate 40% of natural productivity. Much of that is damaging. We need to transition to more holistic and naturally abundant approaches. Like SRI, for example. Tripling rice yields, and increasing 75% for maize and other crops. Permaculture, HM, biological farming can contribute to a better understanding of what it takes to heal the earth and feed us at the same time. And look at the abundant landscapes that can emerge when we manage well using natural principles — http://www.ecoresults.org.
The other overlooked aspect of mitigation is that new biology can favorably alter the earth’s heat dynamics. Bare earth re-radiates more heat than trees and grasses, which also hold moisture. More trees mean more moisture cycling, as well as more cloud and droplet nucleation from leaf emissions such as terpenes and bacteria. All of this adds up. We need less brown showing and more green. More life!! Conventional cropping, grazing, and conservation to some extent, tend to degrade the landscape.
Transitioning farms and farmers is a huge challenge, especially when farmers in the US get $1 Bn in fuel subsidies, and more in other subsidies annually.
Concerning supplying food, Savory is not talking about taking prime cropland for cattle. There is plenty of degraded land.
And here is what is happening in Oz — http://permaculturenews.org/2011/01/26/why-pasture-cropping-is-such-a-big-deal/, and http://www.pasturecropping.com/. The latest is there are now 5000 such pasture croppers in Australia, growing grain in pasture. “By using Holistic Management techniques of herbivores like cattle or sheep, the biomass and available nutrients of that pasture builds even faster. Which means the topsoil, in turn, also builds at a rapid rate.” Hmmm. One inconclusive report, 5000 successful farmers with challenging landscape. That’s only one example of HM success. And the featured farmer, Colin Seis, has sequestered over 30 Tn CO2/ha/an. There are farmers in the US that rotate crops with pasture, and some are using pasture cropping methods. Well managed grass systems can solve a host of issues.
we use global-scale atmospheric CO2 measurements, CO2 emission inventories and their full range of uncertainties to calculate changes in global CO2 sources and sinks during the past 50 years.
Yes, the atmospheric level of CO2 increases about half as fast as the total fossil fuel being burned; that has been true for decades.
No, that Letter doesn’t attribute that to an increase in _vegetation_ as Dan H. claims.
Where’s it going? The Editors’ Summary alongside the Letter sums it up.
About half of the current carbon dioxide emissions are taken up by land and ocean carbon sinks. Model studies predict a decline in future carbon sinks, resulting in a positive carbon-climate feedback, and several recent studies have suggested that land and ocean carbon sinks are beginning to wane. These authors use a global mass balance approach to audit the global carbon cycle, focusing on well-constrained observations of atmospheric carbon dioxide and estimates of anthropogenic emissions and a rigorous analysis of uncertainties. They find that carbon sinks have actually doubled during the past 50 years and continue to increase significantly. There were no signs, as of 2010, that carbon uptake has started to diminish on the global scale
We don’t know; it’s controversial. What they don’t say is — so far we’ve been very lucky. We don’t know why nature is handling half the fossil carbon we burn, and we don’t know where it’s going, and we don’t know if it’s going to bite us in some unexpected way when we find out where it went.
Best guess — mostly into the ocean; if we’re lucky as sinking dead plankton directly into sediments; if we’re not lucky, as increasing acidity, slime and toxic algae blooms.
Re- Comment by Geoff Russell — 8 Nov 2013 @ 6:04 AM
Again, responding only to concern about methane release from the digestive processes of domestic grazing animals:
You said – “Anything which turns carbon dioxide into methane will increase the radiative forcing of the carbon atom considerably.” All plants convert atmospheric CO2 into carbon compounds (plant structure) which, if not digested by a grazing animal, will still be converted into methane and CO2 by natural processes. A cow makes very little difference because it is just a different component of the carbon cycle. A cow doesn’t make methane, bacteria in the cow’s gut makes it, and similar soil bacteria and other organisms digest dead plant matter, if not eaten by the cow, to make methane and CO2.
Methane is released into the atmosphere where it is measured in parts per billion next to CO2 measured in parts per million, not into a small room as in your example in which its concentration could dominate.
Methane lasts less than 10 years while CO2 lasts many hundreds of years. This means that long term constant methane release, after 7 years or so, leads to a constant level of methane in the atmosphere and no increasing warming, while any CO2 release is additive and every small increase in the atmosphere increases temperature for close to a hundred times as long.
Methane released by domestic grazing animals is a small part of total natural and anthropogenic sources. You might as well also gripe about rice farming, termites, or natural lakes or swamps. If you really want to go after methane release into the atmosphere, concentrate on fossil methane released during the development of fossil fuels or just cut to the chase, the fossil fuels themselves. Fossil methane once it is converted to CO2 is additive.
Comment by rustneversleeps — 8 Nov 2013 @ 11:58 AM
“A few posters have suggested that no amount of sequestering can come close to offsetting carbon emissions. Yet, as Ashley Ballantyne’s work shows, current vegetation levels are still soaking up about have the carbon emissions” …
Uh, Dan H, the ocean is absorbing about 40% of current carbon emissions, which hardly leaves room for vegetation to be soaking up 50%, given that about 50% is being retained in the atmosphere.
They clearly include the ocean in their estimate of natural sinks of CO2, and their conclusion is that while sinks continue to increase the amount of CO2 absorbed (not a surprise at all for the oceans), the future is very uncertain. They certainly don’t suggest, as Dan H does, that modest changes in agricultural methodologies can lead to vegetation acting as a sink for 100% of emissions.
The misrepresentation of which you speak is self-imposed. I never said that modest changes in vegetation would act as a sink for all the carbon emissions. In your haste to discredit, you make rather large errors. However, I did say that massive reforestation could alleviate more than the 50% that is currently occurring.
Dan H… still as strident as ever after hanging out here for, what, at least 3 years now? Leads one to believe that he doesn’t really listen to anything the scientists or the astute commenters here say. Rather, he’s always too busy trying to toss his 2-bit disinformation bites our way to actually pay attention to any of the traffic coming back at him.
You’d want to be careful going against all that traffic, Dan. It’s going to run over you sooner or later.
My personal fav was when you interpreted the PDSI the wrong way around. Don’t think you ever recovered from that.
As I mentioned earlier in the thread, I’m a bit familiar with “holistic grazing management” as U.S. federal land management agencies went through a time in the 1980s and 90s when there was interest in the idea. This discussion has focused on the idea that alternative grazing methods can aid in the sequestration of CO2. Certainly healthy rangelands can have an important role in developing robust and adaptable enviroments.
One of the aspects of the Savory grazing method, as I understand it from discussions with range management scientists, is intense grazing of individual pastures with the associated trampling of manure, vegetation and whatever else. If you ever seen rangeland that’s been heavily impacted by grazing you’ll quickly see a potential problem with this approach. Erosion. Trampling of vegetation and soil and whatever else can severely disrupt the soil structure and in the event of heavy rainfall events this soil is easily moved somewhere else. It’s hard for vegetation and soil to sequester anything if it’s being transported somewhere else. If we’re having more heavy rainfall events (and we are, Karl, et. al, 2009) the last thing you want is for rangeland is soil that’s been disturbed to the point of easy mobilization/removal through rainfall events. See Warren from a 1986 Journal of Range Management article for a more thorough discussion.
Let’s quantify the problem. Annual CO_2 emissions are about 30Gt. Convert that to carbon only, and it’s about 8Gt. The density of carbon is about 2 g/cm^3. If I did my sums right, this equates to 4km^3 of carbon, which will generally amount to more than that in a compound (about 3 orders of magnitude more in a gaseous state, which is why sequestering CO_2 directly is not going to happen at scale).
How many km^2 of grassland do we have available for running the experiment? What fraction of the below-ground volume will become carbon, and how deep? And remember, we need to do this every year to make a difference. Even if industrial emissions stop, we will need to keep going for some time before we get down to pre-industrial levels.
You are right, but you can´t count the grass removal of CO2 both to balance the methane emissions and to “solve” global warming problem.
Comment by Rafael Molina Navas, Madrid — 9 Nov 2013 @ 7:02 AM
My recent post was sent after seeing only the blog first page … Nonetheless, I consider it valid.
Comment by Rafael Molina Navas, Madrid — 9 Nov 2013 @ 7:19 AM
Savory’s method is not intense grazing for a long period of time. It is intense grazing for relatively short periods of time with long periods of time for recovery. This is done in an adaptive manner with respect to the actual conditions of the grass and rainfall, not by blindly following some formula.
Frankly I am still having a problem with what the actual numbers are.
Wiki says this:
“Burning fossil fuels such as coal and petroleum is the leading cause of increased anthropogenic CO2; deforestation is the second major cause. In 2010, 9.14 gigatonnes of carbon (33.5 gigatonnes of CO2) were released from fossil fuels and cement production worldwide, compared to 6.15 gigatonnes in 1990″
Which is in the general ballpark of your numbers.
However, it also says this:
“For example, the natural decay of organic material in forests and grasslands and the action of forest fires results in the release of about 439 gigatonnes of carbon dioxide every year, while new growth entirely counteracts this effect, absorbing 450 gigatonnes per year.”
So that means new growth each year absorbs over 100 gigatonnes of carbon each year. So even a few percentage points increase in storage of carbon in by restoring grasslands and forests and/or reduction of fires and deforestation would cancel out a significant portion of the increasing CO2 levels. It does not solve the entire problem and I am advocating it as the only solution. It is just that it is not insignificant.
Given the real political and economic constraints that we live with, isn’t it true that there is no silver bullet solution to our climate problem? Instead we have to do a little here and a little there and in sufficient number of places to come up with a solution? If there are fifty different things we can do that each take care of 2% of the CO2 problem, then that is the practical solution, is it not?
The point is that new growth is already absorbing a lot of CO2. A 2% increase would be almost 2.5 gigatonnes offset. A reduction in fires and other destruction might provide another gigatonnes or so. Not a complete solution but significant.
Same Wikipedia entry also says:
“In 1997, human-caused Indonesian peat fires were estimated to have released between 13% and 40% of the average carbon emissions caused by the burning of fossil fuels around the world in a single year.”
Hank wrote: “… and calculate that the difference is over 100 gigatons of carbon. I don’t quite see how that works out.”
I’ve not checked the 450 number but “over 100″ is obviously not the difference.
I assume it’s supposed to be net primary productivity (see: http://daac.ornl.gov/NPP/other_files/worldnpp3.txt )… which has been estimated at around 5 GtC/yr for grasslands! Obviously it’s inappropriate to use the global NPP number (including that of the oceans) in relation to schemes such as Savory’s.
But the main swindle lies in the unstated assumption that most of the “few percentage point” increase in “new growth” will not be used as food by some organism (or as fuel by fires) and converted back to CO2 (or CH4) within the year but will be somehow sequestered. Sure, it ought to be possible to stimulate sequestration. But only a fraction of NPP can possibly be sequestered!
Another swindle concerns the amount of arable land where such schemes could possibly be carried out. Take a good look at the numbers which have been bandied about in this comment thread!
The user calling himself Jim Bullis was pushing a similar swindle on RC a while back.
Carbon sequestration through sequestration of organic matter could be a great way to bring back CO2 levels to 350-400ppm AFTER a >90% reduction in fossil fuel use. When people propose to offset growing emissions by building soils or burying wood, it’s a swindle.
And that’s not even the worst problem with Savory et al.’s modest proposal: what happens when conditions change and your extra-carbon-heavy soil goes the way of Russian peat?
It’s not enough to sequestrate carbon in the soil for a few decades or even a century! The only sequestration which could be considered an offset has to be stable in the long-run, like coal in the ground. If we’re not confident about future regional precipitation levels, temperatures, acid rain and whatnot we can’t trust sequestration in live soils.
Comment by Anonymous Coward — 9 Nov 2013 @ 5:07 PM
# 82 James Cross I didn’t say anything about the length of grazing, and it really doesn’t matter. If you graze a site intensely you’ve got soil immediately available to be displaced and mobilized/eroded if you have a heavy rainfall event. Don’t take my word for it, though I have actually observed it. Here’s what Warren et al (1986, Journal of Range Management, Vol. 39, No. 6) say: “heavy stocking rates are almost universally detrimental to rainfall infiltration and sediment loss, regardless of the grazing system in use.”
If you lose your soil, arguing about much else is really pointless.
Bingo. While we would all love there to be a ‘just grow more trees’ type solution to the AGW problem… not going to happen. Yeah, stop adding carbon to the atmosphere first, 60mph – 0 in a few years flat, and then we can possibly start talking about pure agrarian/land management solutions to draw down the carbon. Else, it’s just pie-in-the-sky greenwashing stuff you’re talking up here.
Seriously, get a grip. The people here in the comments around the #50 mark: have you done the math?
“I’ve not checked the 450 number but “over 100″ is obviously not the difference.I assume it’s supposed to be net primary productivity…”
I guess this is why you are anonymous coward.
I am just repeating the wikipedia quote:
“… while new growth entirely counteracts this effect, absorbing 450 gigatonnes per year.”
But have translated the CO2 number to carbon number.
I think we have a sort of glass half empty glass half full situation here.
If you want to look at the difference between 450 and 439 which is what the somewhat unexplained “2.6 Pg per year” in the original post may be , although mostly unexplained. You probably think the glass is half empty.
On the other hand, if you realize that new growth takes up about 450 gigatonnes of CO2 or about 123 gigatonnes of carbon every year, you might realize that a small improvement (1-2% in the net) could make a significant impact on the increase of CO2 in the atmosphere. Glass half full.
@ wili 56 7 Nov 2013 at 7:40 PM in reply to 53
“don’t even attempt to address the mathematically indisputable (as far as I can see) fact that grassland sequestration cannot come close to offsetting the current levels of carbon emissions, much less reduce the excess carbon already in the atmosphere”
Actually I was disputing the math just by pointing out the numbers used are irrelevant.
“But for the prairie to play a major role in carbon sequestration, we would need to re-purpose vast swaths of the land that is now in use producing grain”
Agreed. That is part of why the current numbers being used are irrelevant. The numbers used are CURRENTLY roughly correct, but have nothing to do with what the numbers would be if we changed and adopted Savory’s or any number of other closely related management systems that are proven to work. Nor do the numbers reflect anything at all to do with humus. Also it is not only re-purposing land currently producing grain but not sequestering carbon, it is also re-purposing land that isn’t producing much if any at all, because human abuse has deteriorated it beyond its limits to recover naturally in any reasonable period of time. That land even gets worse when fallow.
“this in a world that is about to face major shortages of food as population expands and GW bites ever deeper into yields”
That’s the beauty of it. When you add humus (sequestered carbon) to soil, you actually increase the lands productivity significantly. Ask any gardener who ever added compost to heavy clay soil. Also vast acreage is being used to raise grain, not for human food, but for livestock feed. That livestock does eat grass. If the productivity increases and they are eating grass instead of grain, then those “vast swaths” of re-purposed land are still producing food. Actually more net human food, WHILE still sequestering carbon. If you rotate grain production through wisely you get better yields per acre grain, AND still producing meat from the re-purposed land now in grass, meaning you can even further reduce acreage in grain. You will always have some grain, but the amount of land needed for destructive grain production shrinks until it approaches what we actually need to feed ourselves, instead of the wasteful CAFO system we have now. Keep in mind this has a two pronged effect. The CAFO system is a major part of emissions. So this not only increases sequestration, it reduces emissions too. The use of the term “holistic” is not trivial. It is the WHOLE system that matters. Not just the individual parts.
Matt Owens says:
7 Nov 2013 at 8:55 PM
“#53, I almost agree, but the rate of carbon storage versus the rate necessary to pull CO2 from the air is the critical factor. In Earth history, net soil carbon has accumulated at comparatively small quantities per year, which is why annual CO2 levels haven’t been constantly plummeting over the course of Earth’s history. I looked at the numbers based on IPCC tables for land types by area and carbon storage and plant vs soil carbon, and I conclude maybe 60 GtC could be sequestered in plant and maybe about 60 GtC in soil after some time of decades or longer. We can’t just shove carbon down the throat of the soil, so to speak. We should still pursue the suggestions though, even if it is 60 or 120 GtC, that’s nothing to laugh at.”
And you are almost there too! The sink is somewhere in the neighborhood of ~500-600 GtC. Remember, this is biomimicry. Which means it mimics unguided nature, but isn’t precisely “natural”. By guiding it with human variables of management, natural systems can be boosted far beyond what unguided nature does. In other words you use natural principles, but optimize them for human uses. I think you’ll find that your numbers are dramatically low, instead of decades, that probably potentially could be done in 5 years. But as you said, even if it only helps with 60-120 GT and it takes decades, (after all there is a learning curve for farmers and ranchers) it is still a step in the right direction. Besides we are getting pretty good at forestry too. Since the land with be more productive, it is possible our reforestation efforts will help take up some of the slack while our farmers struggle to learn and catch up to the most modern management methods like this. Solar is coming along too. That will help.
I know one thing. We broke it. It is our responsibility to try and fix it using all the best tools we have. The buffering effect of our oceans has saved us so far. One can only hope we are wise enough to fix it before the oceanic effect starts reaching diminishing returns.
I am also a non-scientist – intelligence analyst – follower of this forum with both personal and professional interest in climate change, and thanks to you certified smart folks for furthering my understanding of the topic. I have spent many years in Alaska and traveling throughout the far north – I do not care care for the changes now occurring.
My question concerns Pleistocene Park (http://www.pleistocenepark.ru/en), a rewilding project in Siberia to recreate, as far as possible, the Mammoth Steppe. The aim of the project is to convert tundra to grassland, through the re-introduction of Pleistocene mammals) or their functional equivalent. Carbon sequestration would increase; a thickening soil layer and higher albedo would provide better insulation than what now exists. The project’s director reports that grassland is replacing the typical tundra flora in the park.
Depending on how you define it there are about three million square miles of tundra. Conversion would be a slow process and I expect there would be resistance from many to remaking large areas of tundra as grassland, though increasing animal populations would be popular.
It this a viable idea or is there some variable, unique to climate in high latitudes, which would argue against it? If viable, I might be able to circulate the idea around a bit.
And if mammoths are brought back, the plan is to reintroduce them to the park – I would have to go take a look.
On the general issue of climate change my professional opinion is that humans will continue to drive the truck, as fast as possible, right over the cliff.
“Approximately 8 Petagrams (Pg; trillion kilograms) of carbon are added to the atmosphere every year from fossil fuel burning and cement production alone. This will increase in the future at a rate that depends largely on global use of fossil fuels. To put these emissions in perspective, the amount of carbon taken up by vegetation is about 2.6 Pg per year. ”
Does this include ocean up take?
If not what is total estimate ocean CO2 up take?
How about inviting the organizers of the TED talks to explain their vetting process on RealClimate. I ran across a link to this video a few months ago and after watcning the first few minutes of it began wonder if TED is now being run by the National Enquirer or the Onion – or worse, have the Koch brothers bought the operation?
” That is part of why the current numbers being used are irrelevant. The numbers used are CURRENTLY roughly correct, but have nothing to do with what the numbers would be if we changed and adopted Savory’s or any number of other closely related management systems that are proven to work.”
Proven to work? Do you have any reference that backs up the claims of massive increases in carbon sequestration, actual measurement and observations over a significant period of time, or is your “proof” merely based on Savory’s claims. Which apparently many professionals believe to be overblown, even without taking into consideration his claims regarding carbon sequestration.
Very good question. One that points out why the math used by RealClimate is misleading at best and completely irrelevant at worst. I am sure it was not purposeful, yet it doesn’t even come close to accurately depicting the complexity of the carbon cycle, as your question points out so well. It is a carbon cycle, not just carbon emissions, and there are multiple sources and multiple sinks currently operating, both long term and short term of each. Activity by mankind has effected both sides of this cycle in multiple ways.
This is why the problem is best seen by first looking at the net results of the entire system instead of calculating emissions alone. Then you can see how changing one part of one side of the equation might change the system as a whole.
The best way to answer your question is by saying the current net annual carbon increase in the atmosphere is ~2.5 ppm/year +/- after taking into consideration all sources of emissions both man made and natural, and all sources of sequestration, both man made and natural. (that number has been rising, so likely the new figures are slightly higher)
Savory has shown that, assuming enough land is restored to health using his management system, ~6 ppm/year +/- reduction of atmospheric carbon into the soil by way of those newly restored grasslands is an entirely reasonable conservative estimate.
2.5ppm/year-6ppm/year = NEGATIVE 3.5ppm/year. In other words we would be actually slowly returning to pre industrial levels unless the 2.5ppm/year increased beyond the 6ppm/year Savory’s method has been shown capable of sequestering.
That certainly doesn’t mean we should rely only on Savory’s method. Not everyone one who tries Holistic management, or the many closely related management strategies closely related, gets it right the first try. There is a learning curve. It is also highly unlikely you could convince everyone to even try, at least in the beginning. There is a lot of vested interest in maintaining the status quo by many in the current concentrated animal feeding operation (CAFO) system and support industries. You can expect a large “Luddite like” reaction from them to any changes, no matter how destructive their system has proven to be.
We most certainly will still need to reforest large areas. We will still need to conserve what we use and develop things like solar. If anything just to keep the scale of the problem to a manageable size during the transition period.
New growth actually takes up about 123 Pg each year, about 15 times human emissions. What the authors, I think, are talking about is the difference between new growth and biological emissions due to decay and forest fires.
> the difference … growth … decay and forest fires.
Yep. And we know preventing forest fires isn’t going to help.
Stopping decay wouldn’t be such a good idea either.
One of the old denier talking points was the claim that carbon cycling is a huge amount, so the little bit people added couldn’t matter. Like saying a huge balance can’t be tipped by a small thumb on one side of the scale.
10 Nov 2013 at 12:16 PM
Proven to work? Do you have any reference that backs up the claims of massive increases in carbon sequestration, actual measurement and observations over a significant period of time, or is your “proof” merely based on Savory’s claims. Which apparently many professionals believe to be overblown, even without taking into consideration his claims regarding carbon sequestration.”
Sure. There are plenty. First I recommend going to my first post #53 and check those reference links thoroughly. Then for real world examples, try contacting people like Joel Salatin, Dan Dagget, Chris Kerston, Greg Judy, Bill Mollison, Gabe Brown, Greg Reding etc. Some of these guys proved it on their own land and others have proved it by helping others time and time again all over the world. If you really want some good raw data, I suggest you contact Jay Fuhrer, District Conservationist with the National Resource Conservation Service (NRCS) in Bismarck, North Dakota. He has a wealth of information, not only about rotational grazing systems, but innovative ways they can be integrated with conventional crop rotations and multi species cover crops, and their effect on soil carbon long term.
I would like to point out that this really is nothing new. Just the cutting edge. The Haughley experiment, started in 1939, although using a different rotational system and includes crops as well, does have the longest running data on soil properties including soil carbon, moisture and temperature.
I’ll leave you with a prophetic warning offered way back in 1947. Pity it has taken us over 60 years to hear that warning.
“As the small trickle of results grows into an avalanche — as is now happening overseas — it will soon be realized that the animal is our farming partner and no practice and no knowledge which ignores this fact will contribute anything to human welfare or indeed will have any chance either of usefulness or of survival.”-Sir Albert Howard
I have always discounted Savory’s claim of Carbon Sequestration and agree with your calculations. However his claim of reversing desertification seems real and worthy of widespread pursuit.
If all we need to do is enforce grazing patterns that mimic natural grazing in the presence of fearsome top carnivores, that is a small price to pay for the benefits in slowing or reversing desert expansion.
Only nuclear power will allow us to reverse the damage combustion has wrought. Solar and wind could protect US lifestyles, but to bring the abject poor out of poverty and provide for 11 billion humans on half as much topsoil will require more industrialization and more energy. But that can take way less space and make more room for nature if food production is nuclear powered and in greater part, indoors.
There is no reason for gloom and doom, or false claims of carbon sequestration trough photosynthesis. There isn’t enough surface area on Earth for 8% efficient photosynthesis to sequester our carbon pollution. But with advanced nuclear power, such as LFTR or LENR or any one of 15 other safe fusion and fission schemes, we can solve it.
11 billion people can have a middle class life style while making more room for biodiversity and nature, thanks to clean safe nuclear power.
Trouble is, there is no nuclear power industry to speak of working with innovative designs like LFTR or LENR. And the industry of the future doesn’t have lobbyists. So progress is excrutiating. Most people’s idea of nuclear power is what we were building in 1967…. a slightly modified bomb plant. And then they complain that it’s not safe. duh…
sj, we try to stay away from banging our collective heads against the nuclear wall around here. I’ll just point out that, since its inception, the next generation of nuclear plants have always been promoted as the great savior of all mankind. So far, that hasn’t worked out quite as advertized.
But to move away from the nuke issue in particular, is it really a great idea to provide humans with vast new sources of energy of any sort? We have had enormous amounts of virtually free energy just from fossil “death” fuels for the past couple hundred years, and what have we done with it? Even leaving aside their GW effects, ff’s subsidized massive destruction of ecosystems, destruction that is still going on (again, even setting aside the GW effects). Is there any indication that humans (and modern industrial capitalist society in particular) will use any vast new sources of energy any more wisely that we have used the ff and nuclear we have already expended?
We all have to get past the idea of limitless growth, and of expanding human power over the earth. Those are among the fundamental mindsets driving the whole calamitous mess in the first place. Our main job clearly has to be how to limit humans, particularly our most destructive activities. (I see now reason, though, to limit art, dancing, philosophizing…as long as those aren’t done in the facilitate or legitimize destructive levels of material consumption.)
Sue Jones: “Only nuclear power will allow us to reverse the damage combustion has wrought. Solar and wind could protect US lifestyles, but to bring the abject poor out of poverty and provide for 11 billion humans on half as much topsoil will require more industrialization and more energy.”
Ill-informed and, with all due respect, blatantly false statements like the above beg for a response based on actual facts about the present reality and near-future potential of solar and wind energy — not only in industrialized countries like Germany, Japan, Australia, and the USA, but in particular to meet the needs of the developing world, where these technologies are already enabling a revolution in rural electrification.
Off-grid solar is already providing electricity to communities in rural Africa, India, the Caribbean and elsewhere who will never get access to grid power from nuclear or any other form of large, centralized generation, because the resources to build either the grids or the giant power plants do not exist, nor do those communities have the wealth to purchase grid power. Instead, they are getting the ability to generate their own power, in perpetuity, from the sun and wind.
However, such a response would necessarily imply rebutting the “only nuclear power” claim in Sue’s comment, and would thus run afoul of this site’s prohibition on “debating” nuclear power, so I’ll stop there.
I would add that feeding “11 billion humans on half as much topsoil” has pretty much ZERO to do with generating electricity, which is all that nuclear power (or wind turbines or solar panels) are good for, so that is a complete non sequitur.
2.5ppm/year-6ppm/year = NEGATIVE 3.5ppm/year. In other words we would be actually slowly returning to pre industrial levels unless the 2.5ppm/year increased beyond the 6ppm/year Savory’s method has been shown capable of sequestering.
Hey, bud. Psst. I’ve got this perpetual motion machine I want you to take a look at, over here in the corner…
But just for the lolz, how many hectares of grassland would we need to have working at 100% efficiency employing the Savory method (whatever that is exactly. There seem to be an awful lot of variants on it) to draw down 6ppm of CO2 per year? And how many years would it take to ramp up to that capacity?
@105 Steve Metzler,
That figure is based on roughly 5 billion hectares worldwide. If for whatever reason you can’t convince the managers of roughly 5 billion hectares world wide to change, it obviously will only work on land it is used. As far as the training goes, it will take time. It isn’t instant. There is a learning curve. Not everyone gets the hang of it first try either. Some land starts recovering in one year. Other lands may take longer. But it is doable.
Here is an example and the potential turnaround in one year from the most meager of resources one could imagine.
wili wrote: “… is it really a great idea to provide humans with vast new sources of energy of any sort?”
Well, let’s hope it is a good idea.
Because given the vast amount of solar energy available to us, and given the rapidly increasing efficiency and even more rapidly plummeting cost of solar technology, and given the extreme simplicity and ease of manufacturing that technology anywhere from abundant and recyclable materials, it’s going to be hard to stop people everywhere from getting their hands on a vast new source of energy.
Of course, stopping that from happening is the point of “the other denialism”: the anti-solar propaganda which proclaims that solar power can never do what it is already doing.
And in fact, I do think it would be a good idea for the billions of people all over the world who have never had access to electricity to have access to cheap, efficient, mass-produced off-grid solar power — power they can generate for themselves, without being beholden to big utilities. So they can replace kerosene lamps with LEDs. So they can have cell phones and computers and satellite communications and Internet access and refrigeration and medical equipment. All of which will drastically improve their lives and expand their opportunities, and all of which can easily be powered by small-scale PV and batteries.
Comment by SecularAnimist — 12 Nov 2013 @ 10:59 AM
Here’s another along the same lines as the original story:
According to his book, large herds of heavy, hoofed animals help force dead plant materials back into the ground, where they are broken down by microorganisms in the soil. Herd migration also churns up the earth, allowing rain to penetrate it further and slowing runoff, and natural “fertilizers” containing additional microbes are left in the herd’s wake.
All of that produces more and better grass, which then feeds the herds the next time they migrate across the land.
“The conservation movement now largely says these large, migrating herds aren’t so bad after all,” said Wendy Millet, the ranch director who formerly worked at the Nature Conservancy. “Ranches can be working landscapes if people understand how animals and land work together.”
TomKat is aiming to mimic the migratory patterns that developed the world’s great plains on a small scale by rotating cows, birds and pigs around the ranch in a deliberate dance.
SA, I get that you are a promoter of the solar industry. Note that I said nothing against it, in particular.
You said: “let’s hope”
Is that all we are left with. What is the basis of your hope that modern industrial civilization will suddenly change its stripe and use all energy supplied to it to do only things that don’t endanger ecosystems?
Most honest people admit that everything has upsides and down sides. Are you claiming that solar is the one thing in the universe that only has up sides? If not, what would you be willing to admit are its down sides? (And don’t say “the it is still to expensive and not wide spread enough”. I obviously mean what are the downsides to this technology being geared up to run modern industrial society?)
Hank, thanks for the comment (#109) on TomKat Ranch. Granted that the “farmer” is a hedge-fund billionaire, it may bring some high-profile attention to the potential for carbon-rich farming. Notice the variety of animals and crops supporting each other in the ranch and connected enterprises: this is the value of an ecological approach. When you put a ton of carbon in the soil, it supports a web of organisms that exponentially grow and sequester more every year.
Comment by Brian Cartwright — 13 Nov 2013 @ 8:54 AM
wili wrote: “Most honest people admit that everything has upsides and down sides. Are you claiming that solar is the one thing in the universe that only has up sides?”
Not at all. I am saying that like it or not, for better or worse, ultra-cheap ultra-efficient photovoltaic materials are already plentiful and readily available all over the world, and there is every reason to expect that trend to continue, with the technology becoming rapidly more powerful and less expensive and easier to produce.
Which means an era in which all of humanity will have access to an unending supply of abundant, low-cost energy. Indeed, the time may come when discussions of energy issues will revolve around the implications of electricity that has become, in the words of that old saw, “too cheap to meter”.
Of course that will have “upsides and down sides” — not only environmental, but social and economic, and some people will experience more of the upside (e.g. rural villages in Africa and India benefiting from off-grid PV) and some will experience more of the downside (e.g. investors in large, centralized fossil fuel or nuclear power plants that will not be able to compete with dirt-cheap PV).
Fortunately, in the context of global warming, solar (and wind) energy have a very crucial upside, which is their ability to very quickly replace fossil fueled electricity generation, which is not only a major source of current GHG emissions, but threatens to become an even bigger source of GHGs if developing countries like China continue to build coal-fired power plants.
I’ve said this before: global warming is certainly not our only big environmental problem, but it is an urgent crisis that must be fixed immediately, if we are going to buy the time to address the other problems. And the only way to do that is with technical fixes that can be applied as quickly as possible — evolutionary changes in the way that human beings relate to the rest of the Earth’s biosphere cannot possibly have any impact in the very short time frame that is required to prevent the worst outcomes of global warming.
Eliminating all GHG emissions from electricity generation is one of those short-term technical fixes, and we have the means to do it at hand, NOW.
Comment by SecularAnimist — 13 Nov 2013 @ 12:31 PM
OOOkaaay, so the only downside to solar power it to its competitors. Thanks for your honest assessment. 8-0
Any thought on what humanity is likely to do with all this too-cheap-to-meter energy?
I believe the correct position answer of the impact of holistic management of grasslands is somewhere between the comment in this article and Savory’a claim.
Per the article: Approximately 8 Petagrams (Pg; trillion kilograms) of carbon are added to the atmosphere every year from fossil fuel burning and cement production alone. This will increase in the future at a rate that depends largely on global use of fossil fuels. To put these emissions in perspective, the amount of carbon taken up by vegetation is about 2.6 Pg per year.
Where do these numbers come from? To do a simple calculation:
1) Per http://en.wikipedia.org/wiki/Carbon_cycle There are 720 Gt = 720Pg of C in the atmosphere. Divide this by 395 ppm gives each ppm of CO2 in the atmosphere equating to 2.43Pg of C.
2) The last three years Mauna Loa data http://www.esrl.noaa.gov/gmd/ccgg/trends/ show an average 5.71 drop in the ppm of CO2 in the atmosphere between May and October each year. This is due to vegetation growth in the Northern Hemisphere sucking down carbon faster than the average 2.06 increase in C in the atmosphere. Therefore for these five months growth in the Northern Hemisphere exceeds decay in the Southern Hemisphere by 5.71 + 2.06*5/12 = 6.57 ppm. Multiply this number by the 2.43Pg C per ppm and you get 16Pg.
Please can West and Briske explain how their annual 2.6Pg for carbon uptake by vegetation relates to this 16Pg for 5 month excess of vegetation growth in the Northern Hemisphere over Southern Hemisphere. Presumably the answer is the annual overall decay of vegitation. The issue is thus how to keep the C out of the atmosphere rather than have the vegetation decay and this is where Savory may have a point – albeit not one with as substantial an impact as he suggests.
Comment by J Robert Gibson — 15 Nov 2013 @ 9:41 PM
J Robert Gibson says:
15 Nov 2013 at 9:41 PM
“Please can West and Briske explain how their annual 2.6Pg for carbon uptake by vegetation relates to this 16Pg for 5 month excess of vegetation growth in the Northern Hemisphere over Southern Hemisphere. Presumably the answer is the annual overall decay of vegetation. The issue is thus how to keep the C out of the atmosphere rather than have the vegetation decay and this is where Savory may have a point – albeit not one with as substantial an impact as he suggests”
I am not West or Briske, but I’ll be happy to take a stab at it. I doubt West or Briske will, because at even a superficial level, the issue you pointed out shows a glaring Math error in the original article. Since I know these scientists are significantly smarter than me, a simple farmer, one can only guess their use of the improper figures was purposeful. But I apologise in advance if their error was a simple mistake.
~2.6 +/- 1.2 PgC/yr is the NET annual uptake into vegetation. In addition, there is ~1.1 +/- 0.8 PgC/yr NET EMISSIONS from land use change, largely from agriculture, deforestation and/or desertification of land that has had all or part of the vegetation killed.
The actual estimate for the total GROSS uptake by vegetation is ~ 123 PgC/yr. So yes, annually that much larger figure can actually account for the seasonal flux you are measuring.
Thus the statement,
“To put these emissions in perspective, the amount of carbon taken up by vegetation is about 2.6 Pg per year. To a very rough approximation then, the net carbon uptake by all of the planet’s vegetation would need to triple (assuming similar transfers to stable C pools like soil organic matter) just to offset current carbon emissions every year.”
is completely false and misleading. To properly put this figure in perspective, the gross figure 123 PgC/yr should have been used, if it is compared to the gross fossil fuel emissions of 8 PgC/yr. Then you are looking at a much more manageable increase of 123 to 131. Or less than 10% improvement, not the 300% increase the bad math using the net figure leads you to believe.
Now what Savory is advocating is to use land that is currently a net emissions source due to land use change resulting in desertification, and add that newly restored land to the Gross uptake of Carbon by all vegetated lands. Since that land is actually a net emissions source due to land use changes, what Savory is saying is probably highly conservative. There is also land considered vegetative that better management could improve. We could probably do very much better than 10% if we include the efforts by conservationists to reforest and improve agricultural management practices in addition to Savory’s method of restoring desertified ground and improvement of rangeland. Then apply new technologies in solar, geothermal etc… to attack the emissions side. In other words take a more holistic approach to all our land and energy use, and not just desertified land. I highly suspect you won’t get much argument from Savory there, but that is my own honest opinion, I haven’t spoken to Savory about it. I have spoken to Peter Holter, CEO of Holistic Management International, and we are in agreement in principle.
The problem doesn’t seem so overwhelmingly huge when you use proper figures and math. A 10%+ worldwide improvement is far more reasonable goal than the 300%+ worldwide improvement implied by the article. Actually convincing people of the importance and getting the social and political changes needed to implement these changes seems to me to be the much bigger hurdle. This highly biased article is certainly not helping there. It is already being used by the deniers who are resisting change.
Thanks, Scott Strough (comments 53 and 116). As you say, even a conservative reading of Savory’s ideas shows he is making realistic claims for restoring lands which otherwise would be a total liability to environment and climate.
I think restoring grasslands needs much greater attention from the public and policy community. When the damage done by industrial agriculture is reversed, the living web of organisms in the soil become an extremely powerful carbon pump. The benefits are not only in the CO2 sequestered from the atmosphere, but also in restoring hydrology which can directly cool the climate.
Comment by Brian Cartwright — 16 Nov 2013 @ 11:25 AM
“Since I know these scientists are significantly smarter than me, a simple farmer, one can only guess their use of the improper figures was purposeful.”
This fits well with the mindset that the only thing keeping Savory’s ideas from being widely accepted is the existence of a professional conspiracy against them.
Which, of course, immediately raises questions in the minds of those who are skeptical of extraordinary claims that fly in the face of accepted science …
“To properly put this figure in perspective, the gross figure 123 PgC/yr should have been used, if it is compared to the gross fossil fuel emissions of 8 PgC/yr. Then you are looking at a much more manageable increase of 123 to 131. Or less than 10% improvement, not the 300% increase the bad math using the net figure leads you to believe.”
How do you get a gross increase of 10% uptake with 100% efficiency?
It is the net figure that is important, not the gross. You’re claiming that a 10% increase in the gross will yield a net increase of 300%, which seems a bit mind-boggling to me.
“Which, of course, immediately raises questions in the minds of those who are skeptical of extraordinary claims that fly in the face of accepted science …”
True enough, except the extraordinary claim that flies in the face of accepted science is “To put these emissions in perspective, the amount of carbon taken up by vegetation is about 2.6 Pg per year.” That is false. 
The accepted figure is around 123 Pg per year. 
[Response: Please dial it down. You may be convinced that gross uptake is the issue, but I am with the authors above in concluding that the only thing that matters is net uptake. Increasing gross uptake without considering concomitant increases in respiration is only half the issue. However, you are more than welcome to argue for the opposite, but not by casting aspersions on the integrity of the authors here. - gavin]
I’ll tell you something else too. Who said this article is the “accepted science” anyway? Briske says his own research is the accepted science? If you are the skeptic you claim to be I suggest you apply the same skeptic thinking to this article you seem to be applying to Savory. Look at that “accepted science” and not just Briske’s own claims backed up by his own paper.
[Response: This line of argument is pretty much a waste of space. Please argue on the merits of the case, not about semantic arguments about definitions. Thanks. - gavin]
” Who said this article is the “accepted science” anyway?”
While the argument is pretty much a waste of space, the argument pretty much hinges on the notion that Savory is turning accepted science on its head. If this weren’t the case, there’d be nothing revolutionary about the claims he makes for his grazing regime …
It certainly isn’t accepted science that changes in grazing methodology can miitgate against current and foreseen human CO2 emissions. If it were thought possible by a significant number of mainstream scientists, you’d find it in AR4 or the upcoming AR5, for instance …
Of course, it is about net uptake; however, the 2.6 number was put out there without really explaining it was the net update.
Also it is clear that reforestation or restoration of grassland will increase respiration also but we would hope not as much since in both efforts we are taking land that is sequestering small amounts (in some cases with destroyed grassland perhaps almost no amount) of carbon to land that would sequester substantial amounts.
On a related note, this is an interesting resource:
Ok I will try this again with a more neutral POV. The fundamental flaw in the article is in inducing the reader to believe that it would require tripling the gross vegetative uptake of the entire planet to offset the net carbon atmospheric increase, while using figures for the net vegetative uptake and the gross emissions. They also ignored the processes involved, including, but not limited to, the differences in properties of grazed lands compared to woodlands, the effect of the ocean and other sequestration sinks, and the fact the while undergoing deterioration and desertification, poorly managed grasslands are an emission source instead of a sequestration sink due to land use changes. These errors of omission combined with the dance of sloppy figures leads the reader to a conclusion orders of magnitude different than anything Savory is claiming. To be fair, that doesn’t necessarily prove Savory correct, all it proves is that this misleading article by West and Briske doesn’t apply to anything Savory is saying.
Fundamentally I agree with this. Sorry I kept writing “update” instead of “uptake” in 122.
It goes back to the glass half full glass half empty I talked about earlier.
If you look at net, you think the problem is impossible to solve with grassland restoration and reforestation.
On the other hand, once you realize that there is an enormous amount of vegetative uptake already (123 Pg) and you look at the amount of destruction of forest and grassland is occurring today, you will realize that if stop the destruction and begin the restoration a significant contribution could be made. Not a complete solution but it is something we need to be doing anyway.
DEFICIENCIES IN THE BRISKE ESTIMATES OF CARBON SEQUESTRATION ON RANGELANDS
By Richard Teague
Professor, Ecosystem Science and Management, Texas A&M University
Senior Scientist of the Borlaug Institute
Associate Resident Director, Texas A&M AgriLife Research
P.O. Box 1658, Vernon, TX 76385
Most research related to grazing management, and thus carbon sequestration potential, on rangelands cited by Briske et al. [1,2,3] has been short-term and has examined the issue from a reductionist viewpoint that ignores the critical influences of scale, and does not use adaptive multi-paddock grazing to achieve sound animal production, resource improvement, and socio-economic goals under constantly varying conditions on rangelands . Superior results in terms of range ecosystem improvement, productivity, soil carbon and fertility, water holding capacity and profitability have been regularly obtained by ranchers using multiple paddocks per herd with short periods of grazing, long recovery periods and adaptively changing recovery periods and other management elements as conditions change [4,5].
The references cited by Briske et al. [1,2,3] concentrate only on differences in rangeland productivity without meaningfully taking into account negative impacts on the environment that can lead to misleading extrapolations. These conclusions cloud, rather than enhance, knowledge about sustainable grazing management and are not relevant to practical grazing management. Multi-paddock grazing research from Australia, Southern Africa, Argentina and USA [4,5] that was: i) conducted at the scale of ranching operations, ii) adaptively managed as conditions changed to achieve desired ecosystem and production goals, and iii) measured parameters indicating change in ecosystem function, have arrived at the opposite conclusion. These published data were omitted in the reviews by Briske et al. [1,2,3].
Many ranchers around the world have used adaptive, multi-paddock grazing management to restore ecosystem services and productivity on degraded rangelands in areas with less than 10 and up to 80 inches of annual precipitation. Many of these ranches in drier areas were initially so bare of vegetation that they would have been classified as desertified. By ignoring such successful restoration examples, Briske and other scientists with the same limited experience are grossly underestimating the potential of management to increase carbon sequestration on the rangelands of the world. Consequently, the inferences and conclusions made by Briske et al. [1,2,3] do not represent the subject adequately because conclusions have been selectively chosen so as to exclude published data showing superior results at commercial ranch scale from adaptively managed multi-paddock grazing. The studies referenced underestimate positive benefits to soil and ecosystem function, so they almost certainly underestimate the potential of rangelands to sequester carbon. The accumulated body of small-scale grazing systems research promoted by Dr. Briske and partners needs to be evaluated in light of the discrepancies with larger-scale studies, and perhaps should be largely set aside as being of little relevance to any discussion of grazing distribution on commercial ranches.
The majority of conservation awards to ranchers operating on native rangelands have overwhelmingly gone to ranchers using multi-paddock grazing of one form or another. These ranchers operate in extensive, heterogeneous landscapes, where they are confronted with the adverse effects of uneven grazing distribution, and their collective ecological and management knowledge using multi paddock grazing indicating the necessity of using adaptive, multi-paddock grazing management to achieve superior outcomes. The articles in the Rangelands October 2013 issue, a journal of the Society for Rangeland Management, support this.
In calculating the potential of rangelands to sequester carbon to offset global climate change and improve ecosystem function we cannot ignore the superior outcomes achieved by conservation award winning ranchers, those who have restored ecosystem function and productivity on degraded rangeland using adaptively managed multi-paddock, time-controlled grazing, or published research that does not refute the results achieved on these ranches.
1. Briske, D., Derner, J., Brown, J., Fuhlendorf, S., Teague, R., Gillen, B., Ash, A., Havstad, K., Willms, W., 2008. Benefits of Rotational Grazing on Rangelands: An Evaluation of the Experimental Evidence. Rangeland Ecology and Management 61, 3-17. http://www.srmjournals.org/doi/abs/10.2111/06-159R.1
2. Briske, D.D., Sayre, N.F., Huntsinger, L., Fernandez-Gimenez, M., Budd, B., Derner, J.D., 2011. Origin, persistence, and resolution of the rotational grazing debate: integrating human dimensions into rangeland research. Rangeland Ecology and Management 64, 325e334.
3. David D. Briske, Brandon T. Bestelmeyer, Joel R. Brown, Samuel D. Fuhlendorf, and H. Wayne Polley, 2013. The Savory Method Can Not Green Deserts or Reverse Climate Change. A response to the Allan Savory TED video. Rangelands 35(5):72-74. 2013
4. Richard Teague, Fred Provenza, Urs Kreuter, Tim Steffens, Matt Barnes, 2013. Multi-paddock grazing on rangelands: Why the perceptual dichotomy between research results and rancher experience? Journal of Environmental Management, Volume 128, 15 October 2013, Pages 699-717, ISSN 0301-4797, http://dx.doi.org/10.1016/j.jenvman.2013.05.064.
5. Teague, W.R., Dowhower, S.L., Baker, S.A., Haile, N., DeLaune, P.B., Conover, D.M., 2011. Grazing management impacts on vegetation, soil biota and soil chemical, physical and hydrological properties in tall grass prairie. Agriculture Ecosystems and Environment 141, 310-322. http://www.sciencedirect.com/science/article/pii/S0167880911000934
Comment by Richard Teague — 17 Nov 2013 @ 10:13 PM
I don’t think it is wise to confuse what I see as two issues of debate running down this thread of late. Farming practices most likely will be able to transform certain barren lands into verdant pastures. Also creating a verdant pasture will absorb carbon that a previously barren land would not. The two issues concern the significance of the transformation and the significance of the absorbing – is either of them significant on a global scale?
Concerning the transformation issue, can this be significant? I do wonder how it can be a subject of debate if the results on the ground are so spectacular. How ever simple a farmer is, would he not adopt the methods of his neighbour with the evidence so obvious? That he appears not to – that is enough to make anyone sceptical of such long-lived claims.
Concerning the absorbing issue which is the main subject of the post, I was not impressed by the numbers presented in the post but the argument that a vast increase in grasslands across the globe would reverse the atmospheric CO2 rise is surely bizarre.
Net or gross numbers? One is caused by incremental CO2 increases, the other by winter. Is there a better number to bandy around? There has been no mention of the 15PgC figure, a figure that has increased 15% over the last 60 years. While the ‘gross’ 126PgC estimates the flux in/out of the biosphere annually, the 15Pg figure is a measure of the effect that flux has on the atmosphere, as measured at MLO. (Of course it depends where you measure it. In size & increase, it is zero in Antarctica & double in the Arctic. MLO thus appears a useful global average.) The 15PgC figure is interesting as our annual emissions from all sources are not so far below 15PgC. (The 8PgC figure for FF quoted up-thread dates back to 2005.)
So can a grand increase in pasturage absorb sustainably year-on-year something like than 15PgC & prevent CO2 levels rising higher? Can it be more significant to the global biosphere than winter?
Here is a question for those who think it may be. What was the impact on atmospheric CO2 when the Sahara turned from grassland to desert? There was a 43Pg increase in atmospheric CO2 over the 8,000 year period (+20ppm). With any emissions being 80% absorbed by biosphere & ocean, that would represent 213PgC. Assuming the source was all the desertification of the Sahara (a very brave leap of faith given the HN cooling over the period), that would make the total desertification of the Sahara, a plot of land of not inconsiderable size, worth 14 years of our emissions. So remind me – how big is this here ranch we’re gonna transform?
To MARodger, #127: This here ranch we’re gonna transform is roughly 12 billion acres, the extent of worldwide grasslands mostly degraded or desertified.
Our scientific sample set of soil carbon storage capacity is severely skewed because so much of it is comprised of croplands that have been mangled far beyond their original state. In general biological conditions on land in the holocene have been blurred by human activity. IOW, it can be hard to discern how the extraordinarily complex systems that are soils would behave in optimal conditions – conditions that we have a pretty good idea of how to re-create should we decide to do so.
There are good reasons to believe that soil carbon sequestration potential is far greater than we currently acknowledge. No matter, eco-restoration of grasslands has such remarkable and widespread benefits – for carbon and water cycles, for biodiversity, for food production (especially in poorer countries) – that we should proceed full speed ahead regardless of carbon-number specifics.
” No matter, eco-restoration of grasslands has such remarkable and widespread benefits – for carbon and water cycles, for biodiversity, for food production (especially in poorer countries) – that we should proceed full speed ahead regardless of carbon-number specifics.”
Which is not the issue under discussion. It is hard to imagine anyone being opposed to improved rangeland management.
The subject of the original post, and the subsequent discussion is whether or not improved rangeland management can fully mitigate human CO2 emissions, as claimed by Savory. Some of us, to put it mildly, are skeptical.
Richard Teague’s post also dodged the issue.
He summarizes by saying “In calculating the potential of rangelands to sequester carbon to offset global climate change and improve ecosystem function we cannot ignore the superior outcomes achieved by conservation award winning ranchers, those who have restored ecosystem function and productivity on degraded rangeland using adaptively managed multi-paddock, time-controlled grazing, or published research that does not refute the results achieved on these ranches.”
This boils down to him saying that even if Savory is wrong about the magnitude of CO2 sequestration, improved rangeland management is a good thing.
It appears that a few people here are attempting to defend Savory’s claim by essentially ignoring it, and changing the question to something else entirely (“are there other benefits to improved rangeland management?”. Yes. Duh!).
I agree with Dhogaza that improving agricultural soil fertility is very important, but when talking about 12 billion acres I would like to know where the water would come from. It takes a lot of water to raise food for grazers and water for the grazers themselves, and easily accessible fresh water is rapidly becoming scarce worldwide. Has this been figured in?
Adam D. Sacks @128.
Your comment sort of leads back to my own comment @127. You tell us there is potential for this transformation to apply to lands equal to a third of global land area. Yet, although this work by Savory dates back to the 1960s, and you tell us “that we should proceed full speed ahead regardless of carbon-number specifics” (which sounds quite an emphatic endorsement to me), you rather pull your punches by saying that we do have a pretty good idea of what to do “should we decide to do so.”
Why is this decision so difficult to make? If this is such a win-win-win situation, what the blazes is stopping it?
I do not know the merits of Savory’s approach. What bothers me about the article by West and Briske is that the authors seem to dismiss the importance of soils in the carbon cycle. That is completely unjustifiable. The authors do not mention the amount of carbon stored in the soil, and the extent to which release of soil carbon (due to erosion, drought, development, agricultural mismanagement, overgrazing etc.) contributes, and has historically contributed, to GHG emissions. The authors: “the amount of carbon in vegetation is currently estimated at around 450 Pg, most of that in the wood of trees.” They fail to mention that the amount of carbon stored in the soil is multiple times that stored in vegetation.
The authors state: “Grasslands represent approximately 30-40% of the planet’s land surface and only a fraction of annual global productivity and carbon sequestration (~20% of global carbon stocks). It is simply unreasonable to expect that any management strategy, even if implemented on all of the planet’s grasslands, would yield such a tremendous increase in carbon sequestration.”
Where the 20% number comes from and what it means is mysterious (it cannot refer to “global carbon stocks” because that would include the deep ocean and so on.) References would have been helpful (this is supposed to be the voice of science right?) Btw where can I find the most current and reliable figures for the carbon cycle? The figures that I find by a simple google search diverge are quite a bit from those given by the authors.
In any case, “only 20%” is a weird formulation. There is no doubt that grasslands are a big issue in the carbon cycle. 30-40% of the global land surface, that’s huge, and it contains a lot of carbon. Proper management methods can have a hugely beneficial impact on many dimensions (soil carbon, water, desertification etc.). The question should be what the best practices are. To dismiss the importance of adopting better practices is widely misleading.
OK, so ‘this here ranch’ is 12 billion acres. I note that land under direct Savory management so far is 200,000 acres, so there’d clearly be a scaling question here…
But 8 Pg translates (if I haven’t slipped up) to 8 billion tonnes of carbon. So once we got all 12 billion acres under Savory’s grazing regime, we’d need to see nearly 700 kg of carbon sequestered per acre, per year, for as long as we keep burning fossil carbon at anything like current rates. (Which, of course, are still accelerating…)
Taking it from the other end, I haven’t seen (in some desultory looking about) any quantitative estimates as to carbon uptake in a Savory-style scheme that I could compare to the target number, but absent any actual estimates, I’m feeling pretty darn skeptical about the TED talk claims made. (Though, qua grazing method, the Savory model may be perfectly wonderful.)
#128 – For comparison, the area of the Sahara is around 2.3 billion acres, or in the region of one-fifth of the 12 billion acres claimed as improvable grassland and potential grassland. According to the numbers given in #127, this translates into the possibility of absorbing roughly 70 years’ worth of emissions.
Thanks for this article, I really wanted to read up on this but have been lacking the time. I never thought it the silver bullet it was claimed to be, but an intriguing possibility to add to the toolbox of climate mitigation. People looking for the one true solution are likely to be misguided when faced with any complex problem.
> “Dan H.
C’mon, show us you can at least be honest enough to correct yourself and withdraw your claim that vegetation aborbs 50% of our carbon emissions.
Or don’t. It’s your reputation, not mine or hank’s, that is at stake.”
My standard disclaimer to all readers, especially new readers, of Real Climate is simply to skip over comments by Dan H. He will never lead one towards a greater understanding of the science or climate, he only serves to distract. The easiest way to make sure you are getting valid information is simply read the main articles and comments from the RC contributors.
It’s been maybe a year or so since I have had any time to comment here, but Dan H is doing the same nonsense as he was back then. He has no reputation to defend, and I do not expect him to claim ownership for his statements. If you spend enough time reading the comments you eventually see his patterns of obfuscation.
Comment by Unsettled Scientist — 18 Nov 2013 @ 11:47 PM
Perhaps a few comments would be useful here to address some questions and apparent confusion about our post. The post was in response to a specific claim made by Alan Savory and then championed in a variety of forums: that his method (however defined) applied to half of Earth’s grasslands (here one must assume arid and semi-arid grasslands) could return atmospheric CO2 levels to those prior to the Industrial Era.
Since it is difficult to understand what exactly is meant by Holistic Management® in this context, and there is no scientific literature that we are aware of that supports a significant net gain of soil carbon across environments in response to his method, we did not attempt to assess what a realistic global number might be. We took a different approach using the available literature and a basic understanding of the global C cycle. Here, what is relevant is the size of the C stocks in the atmosphere, the magnitude of the ongoing additions from fossil fuel burning and cement production, and a simple “order-of-magnitude” assessment of what may be expected from the grassland component of the biosphere. Of course long-term biosphere storage of C is in soils, but any net gain of soil C must first have been fixed by photosynthesis. Again, since photosynthesis and respiration nearly completely offset, what is relevant as a starting point is the apparent net C gain of terrestrial ecosystems. It’s really possible to stop the argument there. The terrestrial C cycle is currently in a significant disequilibrium resulting in an annual net C uptake at a global scale that is still only a fraction of the annual additions to the atmosphere. It is a tall order to make the case that managing grasslands would somehow result in multiples of the current global terrestrial C uptake. However, one can further think about the total biomass of vegetation and ask how many multiples of that must be incorporated into soil (permanently – or at least for “thousands of years”) to draw down atmospheric CO2 appreciably. Recognizing that grasslands are a fraction of the total terrestrial biosphere, and that only a fraction of productivity is incorporated into soil organic matter annually, this results in a very large gap between a plausible expectation and the claim made in the Savory talk. It seems unreasonable to expect that any land management scheme applied to these grasslands is likely to have such an outsized impact on atmospheric CO2.
We did not engage in a detailed discussion of the carbon cycle within grasslands, life-cycle analysis of various management schemes, and several other issues simply because we believe it’s not necessary to address these given the large gap between the problem (elevated atmospheric CO2) and the purported solution (altered management of arid/semi-arid grasslands). Our intent was simple: to place the claim made in the context of the global C cycle.
It seems obvious, then, that any argument made to support the claim should provide evidence that it is possible. This evidence would consist of research published in the scientific literature that has, at a minimum, had the benefit of peer review.
Perhaps an additional comment should be made about other ongoing debates about what is understood to be the Savory Method or Holistic Management®. This post was not about those debates and we think it is important to separate the climate impacts statement from any other claims made in the TED talk or elsewhere.
Some commenters here have argued that the claim was made with the premise that all fossil fuel consumption would stop. We believe this is not at all made clear in the talk and take the quoted statements at face value.
Of course there are many exciting areas of ongoing C cycle research at an incredible range of scales and systems worldwide. We again encourage all readers and commenters here to read Chapter 6 from the recently released Fifth Assessment Report (http://www.ipcc.ch/) for a rich analysis of much of that work.
We look forward to ongoing discussion here and again will look for opportunities to comment here and inline.
Better rangeland management does not affect surfaces temperatures simply by carbon sequestration, but by altering the skin surface. The metamorphosis of grasslands to barren soil can raise maximum skin surface temperatures by 10 to 20C degrees. Since grasslands cover 30-40% of the land surface increasing the vegetation could have a major cooling effect on global land surface temperatures.
Read Mildrexler,D.J. et al., (2011) Satellite Finds Highest Land Skin Temperatures on Earth. Bulletin of the American Meteorological Society
Repairing grasslands provides tremendous economic and biological benefits and controllingour carbon footprint can never heal these habitats. This rant against Savory seems more concerned with saving a CO2 theory than saving threatened environment.
On face value, Briske and West are correct. Savory’s claim is unreasonable. The terrestrial biosphere only nets 3 Gt C/an. How could we possibly expect another 5 or more Gt to be sequestered annually? Consider that most arid land is degrading. Not much uptake there. Consider that there are ranchers who have been successful at transforming depleted, brittle landscapes for some time. How much soil carbon in these cases? There are some who manage well over a ton of C/acre/an. There are some who manage 4 tons per acre, and there have been “outrageous” examples of more than that. Not all sites will take in 4 tons per year, but can we, with good management, average a ton or two? That doesn’t seem unreasonable. The challenge is to get the land to be managed holistically, and that will take more managers, and more animals. Of course, in a wilderness situation with predation, nature becomes the manager. Chris Gill at http://www.circleranchtx.com regenerates his desert by using cattle or a Yeomans subsoil plow to break the crust of the earth and allow water to penetrate and seeds to germinate. After managed grazing with livestock, rewilding occurs. There are, of course, many benefits to HM beyond the scope of the narrow topic here. Regenerated landscapes, as has been pointed out, produce less heat from sunlight through cooler surfaces, and also improves the water cycle. The important thing is to get back into the more natural, more perennial, covered ground approach that built the prairies, savannas, and forests in the first place. That’s what got us here. That’s what will get us out of this mess.
Jason West @136,
Thank you for the clarifying ‘addendum’. What is still missing in all this is a figure for the carbon sequestration potential of regenerating grasslands Savory-style. Without nailing that down, many will remain unconvinced/unsatisfied by this account of the impracticality of Savory’s carbon sequestration claims.
Adam D. Sacks @128 tells us the land available for such regeneration totals approx 5 billion hectares, although it appears way too large an estimate in my view. Savory talks of “about half the world’s grasslands” so perhaps a figure of 2.5 billion hectares should be used. Taking that figure, just to sequester last year’s FF+cement carbon emissions would thus require an uptake of about 4 tC/ha. (CDIAC have just published 2012 preliminary emissions estimates = 9.67GtC.) Indermuhle et al 1999 suggest a conversion from desert to grass/scrub/savannah would sequester 23-37tC/ha, providing sequestration for ~8 years-worth of emissions from 2.5 billion ha. There may be newer estimates that revise this figure. As it stands, a desert-to-grassland conversion appears fall far short of Savory’s claims, even when such large land areas are involved. And this assumes Savory starts from desert.
There are also proposals for forestation schemes which suggest photosynthesis supported by suitable irrigation is capable of sequestering from 5 tC/ha/year to 25 tC/ha/year and inbetween, the last even with a TED conversation. The big difference with Savory’s proposal & these forestation schemes is the size of the plants, forest wood can be harvested to allow sequestration to begin again and they do require serious amounts of irrigation, and investment.
I would appreciate it if those knowledgeable about agricultural carbon sequestration could document how much of this carbon is retained in the soil over time. In other words, does managed grassland that sequesters 4 tons C/acre annually, increase its total C content by 400 tons/acre over a 100 year period?
I presume that you and others who have commented on the cooling effect of plant transpiration are aware that this process is very local and actually absorbs more heat into the atmosphere from sunlight that a bare desert. Just in terms of radiation physics, converting desert to grassland increases global warming.
The key is in the next sentence in the paragraph which gives the context for the figure: “To put these emissions in perspective, the amount of carbon taken up by vegetation is about 2.6 Pg per year. To a very rough approximation then, the net carbon uptake by all of the planet’s vegetation would need to triple (assuming similar transfers to stable C pools like soil organic matter) just to offset current carbon emissions every year.”.
So the number is a net figure to be compared to the net emissions (the human part of the gross emissions which includes the emissions from vegetation).
This is a rough estimate so the authors ignored lots of things.
The big difference is that they have rough numbers while Savory has an unsupported (in the video) opinion.
This is the latest release from an active and over ten year old effort to “establish a common, mutually agreed knowledge base supporting policy debate and action to slow the rate of increase of greenhouse gases in the atmosphere.”
Check it out, explore and visualize data, and share with your friends!
@ #143 I have no fundamental problem in using the net figures. My objection is in using them in a misleading manner IMHO. It is well known that the majority of carbon stored in vegetation mostly returns to the atmosphere through the processes of decay, fire, and/or slow oxidation. There is however a difference in the way grasslands and forests function in respect to the carbon cycle.
In a grassland the net vegetative uptake that stays in the plant is nearly zero like forests, but the difference doesn’t necessarily return to the atmosphere, a significant % can be sequestered in the soil. The % that stays in the soil does vary according to the biology and/or management.
This is why the figures used by West and Briske are wildly and hugely misleading. Instead of tripling the entire vegetative absorption of the planet as Briske implies, What Savory is really talking about is a relatively smaller % increase in total vegetation uptake, combined with a relatively smaller change in the % of that gross vegetative carbon being sequestered into the soil. (when viewed on a global scale)
Just to give you a truer picture of the realistic scales involved, if you increased the total vegetative uptake just 10% and increased the % of that gross uptake that is sequestered instead of re-released into the atmosphere by 10%, you would decrease the gross atmospheric carbon by roughly 13.5 PgC/year in addition to the 2.6 PgC/year given in the article. Our gross FF emissions are around 8 PgC/year. So around a 5 PgC/year net decrease in addition to the what vegetation is sequestering now.
Now I am not necessarily saying Savory’s methods can accomplish either one of those benchmarks. But it gives you a much more realistic and useful benchmark to compare and study to either prove or disprove. I am fairly sure in an already reasonably managed grassland, it probably wouldn’t show that full 10% increase. But in a desertified area, it might show a much higher rate. Same thing goes for forests. If the wood is allowed to decay, a mature forest is nearly a net zero in the carbon cycle. But harvest the mature trees and plant new, in other words managed well, that wood could potentially last for hundreds of years. Just a 10% net increase is all we need, taken on a global scale.
The West and Briske figures presented are useless in understanding the scale of the problem or the potential agricultural/vegetative solutions. Considering the new information I have been seeing for months on methane and CO2 releases from thawing both in tundra and in the oceans, I personally don’t think we have any other option but to try.
[Response: The numbers speak for themselves and are far from misleading. We have no information about expected effects of Holistic Management® on soil carbon on which to base an assessment of its likely impacts. Fictionally large changes in terrestrial uptake can be imagined if you simply make up a number (e.g., as you have here with 10%) and apply it to the estimated gross terrestrial fluxes of the planet, but this is clearly inappropriate. If you look at the estimated global terrestrial sink it has varied from near +4 to around -1 Pg C yr-1 since about 1960 (see slides available here: http://www.globalcarbonproject.org/carbonbudget/13/presentation.htm). This compares reasonably well with global land models. What conceivable mechanism could justify an imagined terrestrial sink that’s some multiple of the currently understood flux? Remember that the gross flux of C uptake is photosynthesis, something that is highly constrained by precipitation in the areas Savory is talking about. Also remember that when we talk about the global C sink, this is an aggregation of large spatial variation in regional sinks. It may be useful here to take a look at the outputs from land models available at http://www.globalcarbonatlas.org. The grasslands we’re talking about are in areas that (as we’ve said) are weak C sinks or weak C sources (check atlas output against Savory’s map outlines). These are not systems that are likely to shift radically to strong sinks in response to any management activity. The net figures are far from useless and accurately reflect the scale of the problem. In thinking about impacts, it’s important to use existing scientific understanding to guide any discussion and there is no science to support your assertion that our figures are misleading. -Jason and David ]
Re- Comment by Scott Strough — 21 Nov 2013 @ 1:24 PM
When a tree is cut down the carbon it contains is released as CO2 and CH4 very quickly on a forest growth time scale. The new growth of the forest will just store up approximately the same amount that was previously released, but it will take longer. Negative benefit.
How grasslands sequester carbon: grasses tend to keep root systems in proportion with top growth, so when livestock graze on high grasses then that land is allowed to rest, the roots slough off the excess growth and their carbon becomes available to microbes as food, polymerizing it into humus. That humus improves soil structure and holds moisture, so there is potentially an exponential increase in growth. That is how the net sequestration can be considerably greater than what the mass of vegetation is at any one time.
Comment by Brian Cartwright — 22 Nov 2013 @ 7:37 AM
“Just in terms of radiation physics, converting desert to grassland increases global warming.” My understanding is that Intensity = Emissivity x Stefan-Boltzmann Constant x Surface Absolute Temperature ^4. Bare earth is considered blackbody, with little albedo, so T^4 is the dominant factor. I have some data from a sunny days, a random sample of which shows leaf temp = 299K and bare soil = 319K, a 33% increase in IR re-radiation. Ground cover and topsoil also mean more water in soil and vegetation. Trees transpire moisture and send cloud and water droplet nuclei into the atmosphere –> rain. Evaporation cools the surface, and the absorbed heat in the water vapor re-radiates when it condenses in the upper troposphere in all directions, including upward toward space –> net cooling. Figure 10′s of millions of acres of desertification per year. That’s an enormous amount of soil carbon released each year. I see no net climate benefit for bare soil.
” The new growth of the forest will just store up approximately the same amount that was previously released, but it will take longer. Negative benefit.” This depends. Well managed woodlots may contain 70-90%, my estimate, the carbon of mature forests, but can allow for healthy regrowth while sequestering carbon in stable, long lived wood products, and converting waste to biochar, etc. Coppicing also has rapid regrowth.
The carbon balance shows that terrestrial biomass and soil nets an extra 3 Gt C per year, so only 60-70% of emissions remain, ~6 Gt C, as ghg’s and ocean acidifying H2CO3. The terrasphere only sinks a net of 2.4% of its 123 Gt productivity, about a 40:1 ratio. It is hard to imagine adding another 246 Gt of productivity to get another 6 Gt sequestered. But that’s not necessarily how it works.
Existing mature forests, for example, are at steady state, with new growth balanced by decay. What if more land were used for forestry? That would mean more growth and less decay until mature. Tropical forests have rapid growth. Hardwood forests are slower, but can e managed for more productivity, and there is more soil carbon in temperate and boreal forests.
Soils can sequester carbon rapidly and can be especially carbon stable. Soil carbon is often under-reported, but this needs to change. One ton C per acre per year is not uncommon, and three or more tons is very doable, with some farmers frequently exceeding this amount. Most soil scientists discount these results, but farmers are doing this.
How can massive amounts of carbon get into soil rapidly and remain there? http://www.nofamass.org/sites/default/files/attachments/Carbon_Building_Carbon_Cycling_John_Kempf.pdf John Kempf cites Horst Marschner’s Mineral Nutrition of Higher Plants. Healthy plants “can release as much as 60 to 70 percent of their total sugar production back into the soil as root exudates. … A healthy plant will have at least as much root biomass below ground as there is plant biomass above ground. So if we have 100 pounds of plant biomass above ground, and an additional 100 pounds below ground, this still represents only 30 to 40 percent of this plant’s total energy production. This is the real secret to building soil carbon effectively and efficiently. We can readily see why forage-based livestock agriculture and perennial polycultures are the most efficient method of building soil organic matter and stable humic substances. Carbon induction is the answer.”
Hay fields can readily produce 3 tons of dry matter per year. That would be about 1.5 tons C above ground and 7.5 total below. Pastures can be as productive and more sustainable. Soil microbes use the exudates for food and produce stable humates, so healthy, microbe rich soils are key.
My bottom line is not whether or not Savory misspoke, exaggerated, or has no peer reviewed evidence. There are farmers transforming landscapes and sequestering carbon, improving the water cycle and physically cooling the planet along the way. The trick is to learn how to gain the understanding to help nature to enhance a carbon cycle that is already doing a lot, and can do much more if we cultivate wisely instead of destructively.
Of course transpiration-evaporation cools the immediate region but this process is slower than radiation from the surface does for removing heat from the earth. I am for improving soils for sequestering carbon, better soil productivity, and a more natural environment, but not because more transpiration will counteract global warming.
I will give this question another shot- Critical to how significant a grassland management scheme is to sequestering atmospheric carbon is the maximum carbon that can be stored/acre and what is the half-life of carbon in the soil. Come on you soil experts, you must be able to document this before making any kind of reasonable global warming claim about grasslands.