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Linking the climate-ecology attribution chain

Filed under: — Jim @ 19 February 2009

Guest commentary by Jim Bouldin, Department of Plant Sciences, UC Davis

Linking the regional climate-ecology attribution chain in the western United States

Many are obviously curious about whether certain current regional environmental changes are traceable to global climate change. There are a number of large-scale changes that clearly qualify—rapid warming of the arctic/sub-arctic regions for example, and earlier spring onset in the northern hemisphere and the associated phenological changes in plants and animals. But as one moves to smaller scales of space or time, global-to-local connections become more difficult to establish. This is due to the combined effect of the resolutions of climate models, the intrinsic variability of the system and the empirical climatic, environmental, or ecological data—the signal to noise ratio of possible causes and observed effects. Thus recent work by ecologists, climate scientists, and hydrologists in the western United States relating global climate change, regional climate change, and regional ecological change is of great significance. Together, their results show an increasing ability to link the chain at smaller and presumably more viscerally meaningful and politically tractable scales.

For instance, a couple of weeks ago, a paper in Science by Phil van Mantgem of the USGS, and others, showed that over the last few decades, background levels of tree mortality have been increasing in undisturbed old-growth forests in the western United States, without the accompanying increase in tree “recruitment” (new trees) that would balance the ledger over time. Background mortality is the regular ongoing process of tree death, un-related to the more visible, catastrophic mortality caused by such events as fires, insect attacks, and windstorms, and typically is less than 1% per year. It is that portion of tree death due to the direct and indirect effects of tree competition, climate (often manifest as water stress), and old age. Because many things can affect background mortality, van Mantgem et. al. were very careful to minimize the potential for other possible explanatory variables via their selection of study sites, while still maintaining a relatively long record over a wide geographic area. These other possible causes include, especially, increases in crowding (density; a notorious confounding factor arising from previous disturbances and/or fire suppression), and edge effects (trees close to an
opening experience a generally warmer and drier micro-climate than those in the forest interior).

They found that in each of three regions, the Pacific Northwest, California, and the Interior West, mortality rates have doubled in 17 to 29 years (depending on location), and have been doing so across all dominant species, all size classes, and all elevations. The authors show with downscaled climate information that the increasing mortality rates likely corresponds to summer soil moisture stress increases over that time that are driven by increases in temperature with little or no change in precipitation in these regions. Fortunately, natural background mortality rates in western forests are typically less than 0.5% per year, so rate doublings over ~20-30 years, by themselves, will not have large immediate impacts. What the longer term changes will be is an open question however, depending on future climate and tree recruitment/mortality rates. Nevertheless, the authors have shown clearly that mortality rates have been increasing over the last ~30 years. Thus the $64,000 question: are these changes attributable in part or all to human-induced global warming?

Yes, argues a pair of December papers in the Journal of Climate, and a 2008 work in Science. The studies, by Bonfils et. al. (2008), Pierce et. al. (2008), and Barnett et. al. (2008), link observed western temperature and temperature-induced snowmelt processes to human-forced (greenhouse gases, ozone, and aerosols) global climate changes. The authors used various combinations of three GCMs, two statistical downscaling techniques (to account for micro-climate effects that aren’t resolved in the GCMs), and a high resolution hydrology model to experiment with the various possible causes of the observed climatic changes and the robustness of the methods. The possible causes included the usual list of suspects: natural climatic variability, the human-induced forcings just mentioned, and non-human forcings (solar and volcanic). Climate models were chosen specifically for their ability to account for important, natural climatic fluctuations in the western US that influence temperature, precipitation and snowpack dynamics, particularly the Pacific Decadal Oscillation, and El Niño/La Niña oscillations, and/or their ability to generate the daily climatic values necessary for input to the hydrologic model. The relevant climate variables included various subsets of minimum and maximum daily temperatures from January to March (JFM), their corresponding monthly averages, degree days (days with mean T>0ºC), and the ratio of Snow Water Equivalent (SWE) to water year precipitation (P). In each case, multiple hundred year control runs were generated with two GCMs to isolate the natural variability, and then forced runs from previous model intercomparison projects were used to identify the impacts of the various forcings.

The results? The authors estimate that about 50% of the April 1 SWE equivalent, and 60% of river discharge date advances and January-to-March temperature increases, cannot be accounted for by either natural variability or non-human forcings. Bonfils et al also note that the decreases in SWE are due to January-to-March temperature increases, not winter precipitation decreases, as the observational record over the last several decades shows. The April snow is a key variable, for along with spring through early fall temperatures, it has a great bearing on growing season soil moisture status throughout the western United States, and thus directly on forest productivity and demographic processes.

Link o’ chain, meet link o’chain.

Update: The new USA National Phenology Network is described here.

254 Responses to “Linking the climate-ecology attribution chain”

  1. 101
    dhogaza says:

    or all consistent with species continuously extending their geographic ranges?

    No. To be consistent with your claim, your claim would need to be true.

    Don’t use garden plants as an example.

    Horticulturists don’t agree.

  2. 102
    Jim Bouldin says:

    Jim, 98: “or all consistent with species continuously extending their geographic ranges”

    Completely false, no such thing. And there is no reason why garden plants cannot be used for phenological monitoring, just not range expansion.

  3. 103
    truth says:

    Secular Animist re [25]:
    Since the intact tropical forests are now showing this large uptake of CO2, why would the answer to the question ‘What is soaking up less ?’ not be —-‘the destroyed tropical forests and peatlands, that have been relegated to nuisance status, due to the demand that global warming be attributed to CO2’?
    Our previous Australian government had set up , back in 1996, the world’s first Government Greenhouse Office, had funded many renewables like solar power[ set up a Solar Cities project, wave power, geo-thermal power, clean coal projects—-and initiated and funded [ with an initial $200million], a Global Forest Initiative—a reforestation policy designed to restore [ and encourage others to do so] tropical rainforests around the world, starting with the great tropical sinks that have been destroyed, and are disappearing as we speak , in our neighbouring country —Indonesia.
    No AGW proponent in our own country —no environmentalist or Greens party member here, or elsewhere in the world, gave any support whatsoever to that initiative—-opting instead to smear the leader who initiated it, labelling him as some sort of climate vandal, because he refused to sign up to Kyoto.
    Making a start on restoring the tropical forests and ending the ongoing destruction just didn’t cut it , compared with drama of demanding the end of coal.
    Of course, that leader was subsequently dumped in the 07 election, on the ‘save the planet from CO2’ issue.
    Why do you not consider that the wholesale global destruction of massive carbon sinks may be the reason atmospheric levels remain high—and why should it be accepted that AGW proponents really believe their CO2 talk, if they don’t consider that ?

  4. 104
    Hank Roberts says:

    Of course they consider that.
    You’re proclaiming as “truth” your belief that it can’t exist because you don’t know anything about it. Consider the irony, eh?
    Current Biology, Volume 17, Issue 8, 17 April 2007, Pages R269-R273
    Primer–Global primary production

    —-Brief excerpt follows, see paper for details, numbers, cites—-

    … Concluding actions

    The idea of planting trees to reduce carbon emissions is often discussed. The scope of the problem can be nicely illuminated at the global scale. If all land use changes of the previous two centuries were reversed, then carbon accumulation in the atmosphere would be 80 PgC less than the present, leading to a global cooling of 0.4°C. By contrast, total deforestation could add as much as 400 PgC to the atmosphere, leading to a global warming of 2°C. Although these are rough estimates they indicate quite clearly that global scale management of forests, particularly in terms of increasing afforestation and reducing deforestation, has a part to play in future global climate.

    The global nature of the problem becomes clear when considering sequestration at the country scale. If the whole of the UK were reforested then this would be equivalent to a sequestration of about 1 PgC. If this directly impacted the atmospheric CO2 concentration then there would be a global cooling of 0.005°C. … The small contribution of the UK to the global change indicates that global mitigation of climatic change can only be achieved by internationally concerted action to reduce carbon emissions.

    The oceanic and terrestrial sinks for carbon currently sequester 60% of anthropogenic emissions, but this fraction is likely to decline through the 21st century. There is limited potential to stimulate this sequestration …. As was the case for afforestation the key to success will be concerted global action in controlling and enhancing species diversity.

  5. 105
    dhogaza says:

    Since the intact tropical forests are now showing this large uptake of CO2, why would the answer to the question ‘What is soaking up less ?’ not be —-‘the destroyed tropical forests and peatlands, that have been relegated to nuisance status, due to the demand that global warming be attributed to CO2’?

    Well, it could be due to the fact that this is one of the stupidest posts ever put online.

    Hank gave you too much credit by providing a serious answer.

    These guys could be geniuses, they could be totally wrong, and the increase in CO2 concentrations, and the obvious physical consequences, don’t change.

    They could be geniuses, they could be totally wrong, and it won’t impact the attribution of global warming to CO2 forcing and consequential feedbacks.

    It’s irrelevant to that issue.

    Until you understand this, please quit wasting spinning electrons and all that by posting your ****?

  6. 106
    Alan of Oz says:

    I was wondering if anyone here could give me a clue on some basic numbers.

    I recall reading several years ago that the biosphere can absorb ~3Gt/yr of excess CO2(e?) from humans and we are currently pumping out ~10Gt/yr. I recently read another article that claimed we pump out ~30Gt/yr and that this represents only 2% of natural and manmade emmissions combined (I’m aware of the specious arguments around volcano’s, etc). Can someone help me clear up my fuzziness or point to a reliable source.

    Specifically, in Gt/yr – What do humans emit, what does nature emit and what is the excess the biosphere can aborb. I understand that the last two are extremely difficult to answer ( hopefully be easier with the new sattelite), any ballpark figures from a reputable source (IPCC?) would be greatly appreciated.

    Note: Name changed from previous posts on this site to distinguish between Alan and Alan Miller.

  7. 107
    truth says:

    Hank Roberts: re [104]
    The ‘truth’ moniker means nothing more than that I’m looking for the truth—certainly not that I claim to know the whole truth.
    It seems to give people on this blog an excuse get personal and to snipe at and try to discredit me, which is a bit small-minded, but no worries —go for your life.
    My remarks were alluding to the fact that AGW proponents , with their enormous influence, very rarely exhort us to do the reforestation, and you’d think that if they really believed the situation is so dire, they’d be taking every opportunity to do so.
    That link you included calls for global action on reforestation, so it just emphasises the narrow focus taken by the high profile AGW proponents in honing in on CO2 almost exclusively.
    Our former Prime Minister did exactly what that article calls for—-established the Global Forest Initiative, and seeded it with $200million—the plan being that other countries would be persuaded to join in the project—the global response the article says is needed.
    For that, he was painted as a global vandal, and a campaign was mounted by global AGW celebrities —especially Al Gore—- to have the Australian voters oust him ‘to save the planet’.
    The party these celebrities championed , has not kept any of its election promises on climate change.
    This is why this issue is as moral and political as it is scientific.

  8. 108
    SecularAnimist says:

    The comment by “truth” at 8:13pm 2/22 (currently #103) really brings into focus the essential core of the fossil fuel industry’s denialist propaganda: anthropogenic global warming doesn’t exist but if it does, it is caused by something, anything other than CO2 emissions from burning fossil fuels.

    And specifically, his suggestion that “environmentalists” have neglected to recognize the contribution of other factors — e.g. deforestation, destruction of wetlands and other land-use impacts; animal agriculture; etc. — to AGW is ludicrously false.

  9. 109
    Paul Gosling says:

    Re- 52

    I would be amazed if slope/aspect were not having an influence on tree mortality if summer drought is the driver of this increased mortality. I am certainly no expert on mountain micro-climates, but I would have thought N and E facing slopes would loose snow pack well after S and W facing slopes, possibly a few weeks after and thus have a shorter drought period, combined with lower summer temperatures. The relationship could strengthen or weaken the hypothesis, I was just surprised the authors had not considered it.

    As for nitrogen – an overview

    See also
    Influence of ozone and nitrogen deposition on bark beetle activity under drought conditions. Forest ecology and management 2004, vol. 200, pp. 67-76

    Phenological Disorder Induced by Atmospheric Nitrogen Deposition: Original Causes of Pine Forest Decline over Japan. Part II. Relationship Among Earlier Phenological Development, Extreme of Minimum Air Temperature, and Forest Decline of Pines over the Japan, Water, Air, & Soil Pollution 117 p205 (don’t have access to this so have only read abstract)

  10. 110

    Alan of Oz #106: Chapter 7 of the Fourth Assessment Report, will tell you more than you wanted to know… well maybe not. There are actually quite big error bars in this.

    Scroll to Section 7.3. Tables, graphs, the lot.

    As for your number of 30 Gt/yr, I don’t know where you got that, but it depends on what you look at. The amount of carbon cycling through the system runs in the hundreds of gigatons, but that is very nearly a closed cycle. The numbers that interest us are the deviations from closure, as they build up over time, and they are much smaller.

    [Response: 30 Gt/yr is probably in terms of Gt of CO2 rather than C (factor of 3.7) – it is often confused in discussions. – gavin]

  11. 111
    SecularAnimist says:

    truth wrote: “… AGW proponents , with their enormous influence, very rarely exhort us to do the reforestation …”

    That is false no matter how many times you repeat it, mister “truth”.

    Ending deforestation, and engaging in reforestation, are widely supported by environmentalists and the scientific community as vitally important measures to mitigate AGW. Both are crucial. Neither is a substitute for ending CO2 emissions from fossil fuels.

    truth wrote: “This is why this issue is as moral and political as it is scientific.”

    Very true.

    Which is exactly why the fossil fuel corporations’ campaign of deliberate deceit and denial of the scientific reality that CO2 emissions from their products are causing global warming, for the political purpose of protecting their profits and their power, is immoral.

  12. 112

    truth paints a picture that I sure don’t recognize. I’ve heard environmentalists–yes, the same ones agitating for meaningful controls on CO2 emissions–fighting to combat deforestation, especially in the Amazon, for decades now. I’ve seen concerned citizens try to take action on their own, putting their own money into various schemes to try and support preservation of the rainforest–sometimes even achieving some mild degree of success. And of course the IPCC reports explicitly include land use in warming attribution.

    From the other side, I’ve heard scorn heaped on anyone, from Al Gore on down, who puts money into carbon offsets. (These commentators usually term them “scams” and “climate indulgences,” ridiculed as pointless acts of penance, and not infrequently allegee to be the source of Al Gore’s post-VP wealth–though this is not just unsupported, but known through publicly-reported data to be false.) And yet, what is the primary activity supported by offset money–why, planting trees and protecting woodlands, of course. What a surprise! Surely those commentators–defenders of forests as truth paints them–would favor such efforts. Wouldn’t they?

    So now those who express concern about carbon emissions don’t care about deforestation? Piffle! They’ve been precisely the ones who were concerned about deforestation all along, and who have tried to do something about it throughout the whole modern “warming era.”

  13. 113
    Chris Colose says:

    # 106 (Alan of Oz)

    The 10 Gt/yr number is pretty accurate (it’s probably slightly less than this). Definitely not 30. You’ll find relevant data at this link

    Concentration-wise, the CO2 equivalent is roughly 1 Gt C = 2.12 ppmv. Roughly half of the CO2 we emit is naturally taken up by the oceans and the terrestrial biosphere.

    The quote that humans emit roughly 2% of all sources combined on an annual basis is on-target, but rather misleading (if you include volcanoes or not). Natural CO2 sources are in equilibrium with natural CO2 sinks, so the net effect on atmospheric concentration change is constrained to be near zero. In fact CO2 change over the last 10,000 years is very small. If “sources” were all that mattered, concentrations would rise without bound until the entire reservoir was depleted, which is obviously not the case.

    The human emissions of fossil fuels take carbon that was buried millions of years ago, and that took millions of years to accumulate, and now we’re putting it back in decades. So, the fossil fuel emissions represent a strong “external input” of Carbon (which leads to CO2) which creates a net atmospheric change. Roughly 100% of the *change in* CO2 concentrations since pre-industrial era is anthropogenic. Comparing the change to the total emissions is not very useful (think of saying that the 1 degree change is small compared to the absolute 288 K temperature. It may be true but not physically meaningful). What’s more, CO2 has a long residence time in the atmosphere, so the anthropogenic CO2 accumulates over time…splitting it up into a “per year” basis is also not very meaningful.


  14. 114
    Jim Eager says:

    truth @107: “AGW proponents…very rarely exhort us to do the reforestation”

    Think Orwell’s “Ministry of Truth” here, because there is simply no way that pen name was chosen on the basis of the plain English meaning of the word truth.

  15. 115
    Ray Ladbury says:

    The ironically named “truth” proclaims: “My remarks were alluding to the fact that AGW proponents , with their enormous influence, very rarely exhort us to do the reforestation, and you’d think that if they really believed the situation is so dire, they’d be taking every opportunity to do so.”

    And that, dear readers, tells you all you need to know about his credibility. Anybody who claims those concerned with climate change are not also concerned with healthy forests is either ignorant, mendacious or illiterate. I will leave it up to “truth” which he considers the “lesser charge”.

  16. 116
    Hank Roberts says:

    Alan, you asked for specific numbers. Did you read the link I posted a couple of responses before your question, the Primer on primary productivity? That includes some good estimates and references.

    Also look in the links at the Start Here button (top of page).

    Searching “biogeochemical cycling” into a Google Scholar search will get you to relevant information. Some from that here:

    Try here:

    Some of what’s known and being estimated about CO2 cycling:

    Ruddiman on forest clearance:

    It’s not likely you’ll get good information just asking some guy on a blog to retype something; look up answers, which will also get you information about how reliable they are and who’s working on improving them.

    If you find the source of the specific numbers you posted, tell us where you got them and we can all take a look.

    Remember most of us here are just amateur readers. One of the scientists may come along with a good answer out of personal knowledge, but they often trust us to figure out how to look stuff up.

  17. 117
    Hank Roberts says:

    Look, ‘truth’ — when you write stuff like “AGW proponents , with their enormous influence, very rarely exhort us to do the reforestation” you sound like a troll. Most of us who’ve actually done field work in biology know this isn’t true in our own experience. Whoever you’re talking about (and you really ought to tell us) may be as dumb as you say. Anyone who claims to be an “AGW proponent” is certainly a nitwit.

    The thing is, nobody with any sense does claim to be an “AGW proponent” — but lots of trolls and fossil fuel PR people use that term a lot.

    So, why do you use it? Where did you get it? Who are you talking about specifically? Why do you believe your sources on this?

    And, if you claim to be a finder of “truth” how do you decide what it is? Tell us how much science you’ve studied, and what you believe.

    Else you just come off like a concern troll dropping one of the very familiar PR talking points. You may not know this is how it sounds.
    You may believe what you do quite sincerely.

    Sincerity isn’t reliable as a basis for evaluating accuracy. Tell us what you believe, where you found it out, and why you consider the source you’re relying on to be good.

    Who are these “AGW proponents” and where did you get the label?

  18. 118
    Hank Roberts says:

    I forgot — there are some in truth who are “AGW proponents” — look up the “Greening Earth Society” aka “Western Fuels Association” for more on their beliefs. And they do oppose reforestation–it interferes with strip mining coal. Maybe they’re the source of the confusion.

  19. 119
    Mark says:

    Chris 113 and Alan 106, I think what may be the problem here is one figure is talking about how much CARBON is being released where the other is talking about how much OXYGEN-CARBON-OXYGEN is released.

    Being there are two big atoms added in to one, it is, per carbon atom, about 3x bigger than the carbon atoms alone.

    Another anomaly may be the use of “CO2 equivalent” which includes all the other GHG that are released weighted by concentration and absorptive power. Obviously, there’s more CO2+CH4+O3+… than there is just CO2 on its own.

  20. 120
    Entropicist says:

    Re # 97 Comment by Chuck Booth.

    Human evolution today is called overpopulation. Global warming is just one consequence of this over-adaptation. So it would be better if there were no more human evolution. Humans seem to have been at their optimal condition, as far as brain development and anatomy goes for several thousand years, nothing further seems necessary and would probably introduce damaging mutations. The colonizing phase of homo sapiens is over. So your peculiar demographic hyperbole seems uninformed.

    “Within a finite period of time past, the earth must have been, and within a finite period of time to come the earth must again be, unfit for the habitation of man as at present constituted.”

    Lord Kelvin

    “Everything has a supreme moment and is crucial; that is where our friends the evolutionists go wrong.”

    G.K. Chesterton

  21. 121
    Hank Roberts says:

    > better if there were no more human evolution.

    The teleology, it burns.

    Please eschew. You can find those people holding forth in many other blogs on their favorite subject.

  22. 122
    Rod B says:

    Hank, I have often used “AGW proponents” but now see how it can have a meaning that isn’t what is intended. What would you suggest? Would simple “AGW believer” do? That doesn’t seem to address the overt nature (believers can be silent) which is where proponent stems from…, but what?

  23. 123
    Ray Ladbury says:

    Re #120: 1)Evolution is off topic.
    2)It is clear from your talk of “optimal conditions” that you don’t understand the subject in any case.

  24. 124
    David B. Benson says:

    The estimate that I recall for excess carbon emission for 2007 CE is

    8.5 GtC from fossil fuels

    1.6 GtC from deforestation

    total excess carbon = 10.1 GtC.

    That is (44/12)x10.1 = 37 GtCO2.

    Should be able to find the numbers here:

  25. 125
    Hank Roberts says:

    Rod, I never have understood why you reiterate your beliefs about others’ beliefs. Sorry. It’s not science.

  26. 126
    duBois says:

    Hank, I have often used “AGW proponents” but now see how it can have a meaning that isn’t what is intended. What would you suggest? Would simple “AGW believer” do? That doesn’t seem to address the overt nature (believers can be silent) which is where proponent stems from…, but what?

    I can live with “AGW proponent”, but then, I often use “Cheerleaders for the Apocalypse” when describing AGW deniers.

  27. 127
    Aaron Lewis says:

    Re 82: Rod, my point was that small changes in temperature as measured by conventional weather/climate metrics can have a significant impact on plants and pollinators. Moreover, that those impacts may be abrupt and quantum rather than gradual and linear.

    My observations say that we do not have a science that ties climate change expressed in degrees to agriculture and the environment. What body of science said, “Starting in 2005, daffodils in Pleasant Hill are going to start blooming in November and December rather than in March”? Mark Lynas understates the problem in “Six Degrees”. We thought linear, and it was *not* linear. We got it wrong. John Muir’s daffodils prove that we got it wrong. We need to get it correct before Mother Nature takes out her red pencil, checks our final exam, and grades us: “Failed”!

    I have not heard of “weather” that lasted for decades since a bunch of geologists were defending their design criteria for a waste disposal repository that was required by law to be stable for 10,000 years. They also missed the concept of climate change. However, that was 1989.

  28. 128
    Gareth says:

    There’s some very interesting stuff about changes in the distribution of marine species around the Arctic in the new The integrated Arctic Ocean Observing System (iAOOS) in 2008 report [PDF download from Damocles], with nice graphics. Very striking maps of changes in zooplankton populations around Britain and NW Europe (ecosystem section pps 48-65), for example.

    Lots of other interesting stuff in there for Arctic watchers – worth a read.

  29. 129
    Hank Roberts says:

    So — this topic is about the Western US science.
    Maybe if we shut up a bit some of the actual scientists working in this area will speak up. I’ll pipe down and hope we hear from some more scientists. C’mon, y’all.

  30. 130
    SecularAnimist says:

    Human “evolution” is now technological rather than biological. This has been true for a long time, certainly since the development of agriculture.

    As such humanity’s “evolution” through technological adaptation is very much to the point.

    Indeed, our survival as a species in the face of anthropogenic global warming now depends not on the slow trial-and-error algorithms of biological evolution — i.e. mutate randomly, keep what prospers, discard what doesn’t — but on intentional, fast-paced technological evolution. We can see that the technological adaptations of fossil-fuel driven industrial revolution are an evolutionary dead end. We need to move quickly to replace them with new and better technological adaptations, to render them extinct before they render us extinct.

    In other words, we could sure use some intelligent design around here right about now. Homo solaris, anyone?

  31. 131
    Alan of Oz says:

    Re#107 – “The ‘truth’ moniker means nothing more than that I’m looking for the truth—certainly not that I claim to know the whole truth.”

    You won’t find truth or certainty in science, at best you will find intellectual honesty and evidence.

    Science is a philosophy based on two articles of FAITH

    1. The “real world” exists.
    2. Other beings like myself can observe what I observe in the “real world”.

    An excellent book on the subject is Sagan’s “Demon Haunted World”.

    PS: Thanks to those who replied to my earlier question.

  32. 132
    Jim Bouldin says:

    Sorry for the delay, but my computer’s been attempting suicide recently.

    Kevin, 43:

    The main point of this post is that when attributing changes in ecosystems at small(er) scales, to human-induced global climate changes, it is necessary (and possible) to connect them to the climatic changes at that same scale, and then to climate changes at the larger scale, retaining justified attribution at each step in the process. Not sure I made or explained this point strongly enough.

    Steve, 44:

    I agree that there is an argument to be made for sequestering carbon via timber products. I do not believe that old-growth should be included in such considerations however–too many other (better) ways to conserve carbon, and too many ecological benefits to old growth. Thanks for the refs.

    Chris, 46:

    Thanks for the additional links. There are LOTS of possibilities, and a real need, for citizen contribution to this problem.

    Hank, 49 etc:

    Thanks for the numerous links Hank.


    The “what’s a few degrees among friends” argument ignores the critical sensitivity of ecosystem elements and processes to temperature’s direct and indirect effects (the “other” climate sensitivity I’ll call it), as Aaron Lewis has brought up.

    Aaron, 56:

    Important point regarding the proper measurement variable. The accumulated sum of thermal energy (a la growing degree days or hours) can be critical. So can maxima and minima or distribution tails in general. So can means. Depends on the process involved. Your overall point about oranism sensitivity to what are considered small, or even non-existent, climate changes is crucial. But you have to be able to tie those small scale climate changes to those at the larger scale, and attribute the latter properly. Not sure you’re getting that point.

    Jenik, 55:

    Thanks for the proper link Jenik.

    John, 55.

    Looks like we Amerians owe the Canadians, big time.

    Joe, 64.

    Thanks. An important goal is to provide probabilistic estimates of cause at as small a scale as possible. The climate scientists have led the way in this endeavour IMO.

    Mitch, 73:

    Like the sign: “Answers to questions, $1. Correct answers, $5”. Ecosystem management? Sure, no problem. Wise ecosystem management? Well that’s going to cost ya.

    Rick, 81:

    Very impressed with your report Rick, comprehensive and well written. Thanks again.

    Rod, 82:

    Changes in local weather “as long as many decades” ARE, by definition, climatic changes. The point is the degree to which such observed changes at small spatial scales can be attributed to human activites that are known to be forcing climatic changes at the global scale. And it’s not just a “connection” (as in synonymous with correlation), but a probabilistic attribution among a suite of possible causes, i.e. an ability to assess the likelihoods of possible causes.

    Harmen, 87:

    Thanks for the link.

    Lawrence, 90.

    Don’t know if they’re the best proof, but they’re the most ecologically relevant, and can certainly be quite sensitive.

  33. 133
    Ray Ladbury says:

    Rod B. asks: “Would simple “AGW believer” do?”

    How about scientist, since anthropogenic causation of the current warming epoch is simply what the evidence suggests?

  34. 134
    Hank Roberts says:

    > Managing western forests

    Those in the field know this book; others would find it eye-opening, I think:

    A Conspiracy of Optimism: Management of the National Forests since World War Two
    PW Hirt, U of Nebraska Press, 1996
    ISBN 080327288X, 9780803272880

    Cited by 111:

  35. 135
    Jim Bouldin says:

    Ike, 80.

    Thanks Ike. Two of the best refs for large scale plant and animal phenology and distribution changes are: Parmesan and Yohe (2003) Nature 421:37-, and Parmesan, (2006), Annual Review Ecology and Systematics 37:637–69. Also Root, 2003, Nature 421:57-

    Pat, 94:

    That’s the news story, in Science, of the article I’m referring to here. Unfortunately, even it is not free w/o subscription (what are they thinking?).

    xyz, 95:

    Look also at the table in the link provided above to the Netherlands data by Harmen ( Look at 2nd column from right in Table 2, which is the number of days advance from the 1940-1968 mean (presumably the mean of the yearly medians, but i can’t read dutch–Harmen?), to the 2007 median. Make your own interpretation.

    Paul, 109:

    I don’t think you understood my explanation. N to E facing slopes DO hold snow longer, but that’s not the point here. There is not necessarily any reason to assume the mortality RATE would increase differentially between the two aspect classes. But supposing there were, the data show that any such effect is minimal at best. Only 13% of the plots showed no increase, and even if you assume the worst case scenario (all 13% located on northerly facing slopes, thus maximizing the effect of slope on mortality, given the data), there’s still only a small effect. The only way aspect could be an important factor is if southerly slopes are heavily favored in the plots, which I’m pretty sure the authors would have noticed and accounted for, given that they were careful to account for a number of other possible confounding effects. I’m looking at the N article cited and others. Am skeptical but willing to be persuaded.

    Aaron, 127:

    I agree with the gist of your comment (it most definitely is anything but linear), but regarding the suitable metric, growing degree hours, where hourly data are either available or interpolate-able, should do what you want.

    Animist, 130

    I vote for your last line as quote of the post.

    captcha: be disturbing. Guess we got that one down.

  36. 136
    Entropist says:

    Re # 121, 122, 123.

    What does teleology have to do with overpopulation? Human overpopulation is the cause of global warming. I believe I said the human brain and genome have not changed for several thousand years, hence ‘optimal’. This is just the English language. Any changes like say the Sickle Cell as an adaptive trait to environmental stresses are indeed deleterious and unhealthy. Its clear you are ignorant of basic biological concepts like ‘colonizing phase’ that is an evolving, growing, species, hence my reference to human overpopulation, and ‘climactic phase’ where a species has filled up the carrying capacity of its surroundings. But apparently we’re dealing here with paranoia, where acolytes of outdated notions of progress and Darwinism feel threatened by the laws of thermodynamics.

  37. 137
    Ray Ladbury says:

    Entropist says… well, not very much, really.

    Ho hum. Too early in the morning for a boring post like that. Come back when you get new material…or when you understand biology or thermodynamics for that matter.

  38. 138
    Dan says:

    Off topic, I realize, but how disappointing this is for science: The NASA global CO2 monitoring satellite failed to reach orbit.

  39. 139
    Paul Gosling says:

    Re 135

    I think you are missing my point. My general criticism of the paper is that the authors have too easily concluded that climate change is the cause of increased tree mortality without proper consideration of other factors. I suspect that there are a number of factors involved acting synergistically, one of which may be nitrogen deposition, one of which is probably increased drought stress due to higher temperatures, there may even be other possibilities, such as a change in species dominance to shorter lived species (pure speculation there). My point about slope/aspect is not that it is a factor in increased mortality (it hasn’t changed after all) but that if water deficit is an important factor in increased mortality there should be a relationship between aspect and mortality. It will be more subtle than N facing slopes have seen reduced mortality and S facing increased, there are other factors involved as well, but if it is not a factor I would suggest that drought is not the primary driver of increased mortality. The authors may have considered it, but they do not indicate so in the supplementary material and if they did not it is a surprising omission.

  40. 140
    Nick Gotts says:

    ““Within a finite period of time past, the earth must have been, and within a finite period of time to come the earth must again be, unfit for the habitation of man as at present constituted.”

    Lord Kelvin

    “Everything has a supreme moment and is crucial; that is where our friends the evolutionists go wrong.”

    G.K. Chesterton” – Entropocist

    Argument by quotation: the favourite approach of the irrational.

  41. 141
    Aaron Lewis says:

    # 135 Dr. Bouldin,
    Attribution is discussed in IPCC Technical Paper 5, “Climate Change and Biodiversity”. The required chill hour data is on the UC Davis Pomology site. Perhaps one of your undergrad students would like to do a paper on “Changes and Effects of California Chill and Frost Hours as a Result of Global Warming?”

    It concerns me how little of Technical Paper 5 made it into AR4, and particularly the Summary for Policy Makers. From here, it seems that a primary and immediate source of risk from global warming that should be in the forefront of every policymaker’s mind was left out of the Summary for Policy Makers, i.e., current and potential impacts on plants and hence impacts on food supplies.

  42. 142
    Mark says:

    Paul 139 are you misapprehending and making the jump from “climate changes can easily explain most of the tree mortality” to “climate change is causing tree mortality”?

    We’ve already had a couple of points on other threads about denialism having a big problem with multiple causations and with one being the main but not only cause.

  43. 143
    Jim Bouldin says:


    You state: “My point about slope/aspect is not that it is a factor in increased mortality (it hasn’t changed after all) but that if water deficit is an important factor in increased mortality there should be a relationship between aspect and mortality… if it is not a factor I would suggest that drought is not the primary driver of increased mortality”

    NO! You are NOT getting the point. Please re-read my two responses above to this claim re aspect. You are throwing out a bunch of random possible influences without any real reason to believe that any of them are important, or worse, that have evidence to argue that they are probably NOT important (e.g. aspect). There is no inherent reason to believe that increased mortality rates are caused by aspect considerations, or N loading for that matter, which generally helps not hurts, tree health and vigor. As for transition to shorter lived species, absolutely not, these are undisturbed, late successional forests, dominated by long-lived conifers.

  44. 144
    Doug Bostrom says:

    In related news, the Orbiting Climate Observatory made an ironic plunge into the Antarctic region after a fairing failed to separate during launch:

    I had a bad feeling about this when I saw the launch vehicle being assembled with bucket trucks, looking completely orphaned in the scrub at Vandenburg. It appears climate change research is given some of the same lip service we pay to children’s education: oh so very important but we can’t actually bring ourselves to spend enough money…

    [Response: In the absence of any actual information as to what the background cause was, assuming that the failure was because of penny-pinching is completely premature. – gavin]

  45. 145
    Doug Bostrom says:

    re 144: Point taken, and the Taurus track record has been fairly reasonable, with only about a 20% failure rate. I guess my general thrust was more along the lines that you won’t see Rupert Murdoch’s latest geosynchronous drivel pump (AKA direct broadcast television relay) being handled the the way the Carbon Observatory was. More money is larded into that type of launch and it shows up in the success rate. What’s more, there’s no immediate plan for handling this failure with a replacement, another sad diagnostic that makes me wish we had a greater sense of urgency in funding climate science.

    [Response: Remember too that OCO was an experimental instrument to demonstrate proof of concept (see here) and wouldn’t have happened at all if it was much more expensive. This is just one of those things unfortunately. – gavin]

  46. 146
    Mark says:

    Doug, 145, 2 out of 8 launches is what I read. 25%.

    And the first time this version was used.

  47. 147
    Brian Dodge says:

    Drought triggered tree mortality in mixed conifer forests in Yosemite National Park, California, USA; GUARIN Alejandro (1) ; TAYLOR Alan H. (1) ;

    “We sought answers to the following questions: (1) Do periods of high tree mortality correspond with drought? (2) Do spatial and temporal patterns of high tree mortality vary by slope aspect? and (3) Do different tree species exhibit similar temporal and spatial patterns of tree mortality? We identified temporal patterns of tree mortality on three north- and south-facing slopes by determining the death date of trees using dendrochronology. Tree death date frequency was then compared by slope aspect and to Palmer Drought Severity Index (PDSI), and April snowpack depth as measures of growing season water availability. The frequency of tree death dates was negatively correlated with annual and seasonal PDSI and April snowpack depth, and more trees died in years with below normal PDSI and snowpack. Correlations between tree mortality and drought were evident only for multi-year periods (2-5 years).

    Temporal patterns of tree death were similar on north- and south-facing slopes and among species, but the density of dead trees was higher on north than south slopes. Dense stand conditions caused by fire suppression, and the coincident outbreak of bark beetles during drought, may have limited any buffering effect of topography on tree mortality.”

    hit # 2 on google search ‘aspect “tree mortality”‘

  48. 148
    Hank Roberts says:

    We can hope the labs have enough spare parts to
    recreate the satellite while the Japanese satellite is still on orbit, so they can do the overlapping coverage planned. Hope they put a tip jar open online (wry grin).

  49. 149
    Brian Dodge says:

    “atmospheric nitrogen deposition increased tree susceptibility to beetle attack”

    “it may be concluded that the combined effects of accelerated phenological progress and reduced frost hardiness caused by acid deposition, mainly nitrogen deposition … are the original main factors of mortality of pine trees…”

    “We found that the strongest predictors of tree mortality were regional patterns of precipitation and temperature, though the magnitude and direction of the effects of these varied among functional and taxonomic groups.

    In terms of anthropogenic pollutants, increases in both acid and nitrogen deposition moderately increased mortality, while the effects of ozone were weak but statistically significant.”

    “Four years of severe drought from 1999 through 2003 led to unprecedented bark beetle activity in ponderosa and Jeffrey pine …
    Pines in the San Bernardino Mountains also were heavily impacted by ozone and nitrogenous pollutants …..
    Tree mortality and beetle activity were significantly higher at the high pollution site.”

    “Given the rapid colonization by mountain pine beetles of former climatically unsuitable areas during the last several decades, continued warming in western North America associated with climate change will allow the beetle to further expand its range northward, eastward and toward higher elevations.

    It appears to me that the underlying causes of increased tree mortality are primarily driven by global warming – early bud break before the last killing frost, drought and other changes in precipitation, expansion of beetle activity – and that nitrogen deposition intensifies some of the effects (decreased frost tolerance, increased beetle attack), rather than being a prime cause.

  50. 150
    Brian Dodge says:

    In testimony before House aviation subcommittee hearings about Flight 1549 Tuesday “The bird problem has been growing. Since 1990, the number of Canada geese that live year-round in the country rather than migrating has grown from 1 million to 3.9 million,” John E. Ostrom, chairman of the Bird Strike Committee-USA, testified.

    Another problem to blame anecdotally on AGW? &;>)