CO2 is not the only greenhouse gas, and greenhouse effects are not the only CO2 problem
) The title here should strike a familiar theme for most readers. Climate forcings do not just include CO2 (other greenhouse gases, aerosols, land use, the sun, the orbit and volcanoes all contribute), and the impact of human emissions often has non-climatic effects on biology and ecosystems.
First up last week was a call from Michael Prather and colleagues that the production of a previously neglected greenhouse gas (NF3) was increasing and could become a significant radiative forcing. This paper was basically an update of calculations done for the IPCC combined with new information about the production of this non-Kyoto gas.
Most of the media stories that picked this up focused on the use of this gas in a particular manufacturing process - flat screen TVs. Thus the headlines almost all read something like "Flat-screen TVs cause global warming"! (see here, here, here etc.). Unfortunately, very few of the headline writers read the small print.
NF3 is indeed a more powerful greenhouse gas than CO2 (as are methane, CFCs and SF6 etc.), but because it is much less prevalent, the net radiative forcing (as with other Kyoto gases) is much smaller. Unfortunately, no-one has any measures of the concentration of NF3 in the atmosphere. This is likely to be increasing, since production has stepped up rapidly in recent years, but the amount of gas that escapes to the air is unknown. Manufacturers claim that it is only a very small percentage - but historically such claims have not always been very reliable. However, it is almost certain that NF3 has not caused a significant amount of global warming (yet).
The one issue that many stories did get wrong was in the comparison with coal. Prather's paper compared the effect of the entire global production of NF3 being released into the atmosphere with the CO2 impact of one coal-fired power station. Since that is the maximum estimate of the current effect, and only matches a single power-station, the subtlety of the comparison got a little lost on the way to "Flat screen TVs 'worse than coal'" story….
Needless to say, no-one should be throwing away their flat screen TVs because of this (it's not in the use of the TV that causes a problem), but manufacturers will likely need to step up monitoring of NF3 leakage or switch to an alternative process which some have already done.
The second story getting some attention, is the ocean acidification issue. As we've discussed previously, the increased take up in the oceans of human-released CO2 is rapidly increasing the acidity (lowering the pH) of the oceans, making it more difficult for many carbonate-producing organisms to produce calcite or aragonite. These organisms include corals, coccolithophores, foraminfera, shell fish etc.
Both of these issues are relevant to the ongoing climate change discussion and it's good to see the media picking up (albeit imperfectly) on these ancillary discussions. But as with the "North Pole" lightning rod discussed last week, there always needs to be a hook before something gets wide press (the 'tyranny of the news peg' as ably described by Andy Revkin). In the first case, there was a link to a popular consumer item and in the second, there has been a concerted effort to get the ocean acidification issue higher up the agenda.
The fact of the matter is that most of what goes on in the sciences is completely (and usually correctly) well below the radar of the public at large. But when there are discoveries and issues that do have public policy ramifications, getting the public to pay attention often requires finding just these kinds of resonances. Now if there was only a way to make sure the story underneath was accurate….
7 July 2008 at 9:44 PM
Speaking of getting the details right, you say plasma TVs, but the articles you cite say LCD if they specify at all. Which is correct?
[Response: Not sure - this press release simply says ‘flat panel displays’, as does the Prather article. NF3 is used in plasma etching, but I have no idea if that is connected specifically to plasma TVs. To be on the safe side, I deleted the ‘plasma’ reference above. If anyone has more information, please let us know. - gavin]
7 July 2008 at 10:11 PM
The bad thing is that it has a radiative forcing of 0.21 W/m^2 per ppb and we do not have atmospheric measurements, the good thing is that its release is being looked at in terms of picomoles per mole. I’m curious as to where this gas cuts off outgoing radiation (definitely must be in the atmospheric window), but I can’t find anything on HITRAN.
7 July 2008 at 10:45 PM
Only slightly off topic… but how extensive this kind of rhetorical attack is…
HERE
The time you take from your real work is appreciated more than you can possibly know.
Thank you, for what you do, and for keeping us informed.
7 July 2008 at 11:16 PM
A third one, which as far as I know, has gotten little attention, since it’s more local, is that of the negative health effects of higher CO2 concentrations in already-polluted areas, i.e., like some cities here in California.
Stanford Prof. Mark Z. Jacobson has a bunch of interesting papers, but in particular, it’s worth reading:
Testimony to House April 2008.
7 July 2008 at 11:48 PM
Exactly.
“IGNORANT AMERICA: JUST HOW STUPID ARE WE?
By Rick Shenkman, Tomdispatch.com
Millions of Americans are embarrassingly ill-informed and
they do not care that they are.
http://www.alternet.org/democracy/90161/”
[edit - please stay on topic and off politics.]
8 July 2008 at 12:16 AM
I sometimes post to DeSmog.blog, or RealClimate.I’m going to review whar I’ve said before.The oceans have absorbed so much co2 that they have masked the true extent of the climate crisis.We had plenty of warning as much as 10 years ago about the increasing acidification of the oceans. I’m glad it is getting some press, but for those of us who have followed the news closely it is old news.Also, as I’ve said, most people seriously underestimate the danger of the methal(frozen methane) hydrates at the bottom of the worlds oceans melting.Along with massive expulsion of methane and co2 from melting peat and tundra in the Arctic, but especially in Siberia, the methal hydrates meling will indeed seal our fate.The Greenland ice sheets and Arctic ice, as well as the Antarctic major ice shelves, are all in real, real, danger of melting completely. The floods in the Midwest are jut a start.Desertification is increasing on a logarithmic scale upward, and the oceans have begun serious upwelling current changes, especially in the salinity levels off Greenland, a key downward force on the North Atlantic current.My research indicates that the North Atlantic current has already begun to change.
And yet, at the current G8 summit, the US continues to obfuscate, minimize, and dimiss the severity of the problem.Now,finally, there is a call for an 80% reduction in manmade co2 by 2020. Finally. If you look at my posts, I said an 80% reduction must occur right now, for there to be any chance at all of averting real catastrophe for the planet.Finally, some are saying 80%, by 2020.
I want the entire internet community to understand the way I feel.
[edit - this is not the place for partisan politics, no matter how heartfelt]
Mark J. Fiore
markfiore50@hotmail.com
Boston College Law School,1987 and Harvard University, 1982
8 July 2008 at 2:27 AM
Mr Schmidt, I have read the links and understand the principal points. Thanks for the always interesting comments on this site.
There has been an agreement to agree, at G8 today, to reduce emissions by 50% by 2050. Assuming all agree to reduce by 50% and achieve it (an heroic assumption), what affect will that have on ocean acidification. I tried to find out for myself the answer to this question by reading the original paper but it is a pay website. But perhaps the original paper doesnt contain enough information anyway.
8 July 2008 at 2:52 AM
Indeed. For many years in dealing with policymakers I have pointed out that the lowering of seawater pH alone, via atmospheric CO2, justifies significant emission reductions.
8 July 2008 at 2:54 AM
a very interesting line of thought, pegging (with only minimal condescension
the issues to both the media and to the public consciousness (or unconsciousness as the case may be) - there is another thought, that homo sapiens has split into two species, one moral and one immoral, you come across the notion now and then
anyway, I appreciate your digression, thought provoking, well done, thanks.
8 July 2008 at 4:03 AM
Probably explains why it is best to just stick with global warming and CO2 with some reference to rain forest destruction and land use changes. after all Al Gore and others have done enough work in this arena to get the momentum going and even the G8 have committed to 50% CO2 cut by 2050.
Is this enough of a cut to stop AGW from being the disaster it is reported it is goign to be with BAU scenarios?
8 July 2008 at 4:43 AM
I note that the Press Association report states, “Scientists have calculated that it [NF3] has a half-life in the atmosphere of 550 years.”
I assume this half life may relate to the reaction of NF3 with, presumably, oxygen and/or water to form more stable end products that are either not GHGs or are rapidly washed out of the atmosphere, such as N2 and HF respectively. Maybe NF3 also slowly spontaneously decomposes. Its iodine analogue, the solid NI3, easily prepared by adding conc. ammonia solution to iodine crystals, does so: it explodes with a loud bang and a puff of violet smoke if sprinkled on the floor and trodden on. It was beloved of miscreant sixth-formers in the days before health and safety took the pleasure out of chemistry lessons.
I have often wondered why the duration of CO2 (and other GHGs) in the atmosphere is not generally expressed in terms of half lives. Rather, it is usually stated that ‘CO2 lasts for a century or more in the atmosphere.’
Can anyone shed some light on this question of half lives?
[Response: For NF3 the half-life is dominated by photolysis (presumably in the stratosphere) and the reaction with the O(1D) radical. Since these reactions depend on the concentration of NF3, an exponential decay process with a well-defined half-life is a good fit. For CH4 or CO2, the chemistry is more complicated (much more so for CO2) and half-lives less useful a concept. For CH4, 12 years for the perturbative half-life (longer than the ~8 year residence time) is reasonable, while for CO2 the best approximation is a combination of 5 different exponential processes with half lives that range from 3 to 100,000 years. Thus there is a component of CO2 emissions (roughly 15%) that is effectively in the atmosphere forever. - gavin]
8 July 2008 at 5:06 AM
“Needless to say, no-one should be throwing away their flat screen TVs because of this (it’s not in the use of the TV that causes a problem)…”
Isn’t the higher energy use of plasma screens the biggest problem here? Or is that mainly because the newly bought screens are usually much larger than the old ones? See for example:
http://www.guardian.co.uk/environment/2006/aug/13/energy.nuclearindustry
8 July 2008 at 5:38 AM
“Now if there was only a way to make sure the story underneath was accurate….”
Well. For a start, it could help if the IPCC and the real climate scientists made a commitment to tell the truth. One example: http://www.onlineopinion.com.au/view.asp?article=7553
And in your response, please don’t just ad hom me. How about a reasoned response showing why this reference is actually incorrect.
[Response: Well since you seem convinced that we are dishonest already, what is the point? However, a moment’s thought should tell you that the whole article is based on false premise: When reviewing an article, do you comment on the 90% of the paper you think is ok, or on the 10% you think is wrong? Thus parts of the IPCC text that people agreed with were generally not commented on - for instance, I read the SPM and did not comment - because I was in agreement. Hundreds of scientists read the various drafts of the SPM, and only a few raised relatively minor issues. If it was one of my papers, I’d have been pretty happy. But even if you don’t think the IPCC reviewing is rigorous (even though it is, and it is certainly a lot more rigorous than anything peddled by Harris and company has undergone), how about all the reviews by the National Academies, and professional societies and special committees? The number of scientists who have explicitly endorsed the central IPCC conclusions is legion - as anyone who has ever gone to the AGU or EGU meeting will see and as anyone who reads the literature will see. It’s a valid argument to say that consensus does not guarantee correctness, but it’s complete nonsense to argue there is no consensus. - gavin]
8 July 2008 at 6:34 AM
The fault for climate change having been “well below the radar of the public at large” for decades has been with NOAA National Weather Service (NWS) headquarters, NWS weather and NWS river forecast offices - not with the media and others not “finding just these kind of resonances”.
8 July 2008 at 7:42 AM
Mark,
I don’t think it’s a good idea to attack Republicans per se. I know the GOP has become significantly far-right in recent decades and that almost all the loony public attacks on AGW theory have come from GOP apologists like Rush Limbaugh and Ann Coulter, not to mention the egregious James Inhofe. Nonetheless, there are Republicans, even Republican office-holders, who recognize the problem and want to do something about it. In addition, half the audience is Republican, and we don’t want them to think this is a Republican/Democratic issue. That way lies endless gridlock. The issue must be non-partisan or it will not get solved.
8 July 2008 at 7:46 AM
A quick question from a relative layman: if we reduce the concentration of CO2 in the atmosphere will the oceans then start releasing CO2? Or is the absorbed CO2 in the oceans basically there to stay until it’s used by some biological process (reef building, shell formation, etc)?
If it’s the latter it’s tough for me to see how a (much needed!) reduction in atmospheric CO2 mitigates the oceanic PH level.
8 July 2008 at 8:05 AM
The story does not need to be accurate. It only needs to be true!
If there is a there is a theat to humanity from NF3 then whether the current production is equivalent to one, one thousand, or one million coal power stations is irrelevant. The public only need, or want, to know that something should be done about it.
Meanwhile, the scientific truth is being severely compromised by scare stories about ocean acidifcation. How can those species be under threat when they have survived much higher levels of CO2 in geological past? Levels of atmospheric CO2 far higher than even those predicted for the next century? That sort of story does much more to sap the faith of the intelligent layman in scientists, than any confusion by journalists about numbers of power stations.
HTH,
Cheers, Alastair.
8 July 2008 at 8:16 AM
Or, perhaps they’ll stop voting Republican, as I did when Reagan hit the national scene and it became clear that the socially responsible, science literate, and fiscally conservative bits of the party I grew up with was doomed to irrelevance.
Now, I didn’t vote for Nixon because of character issues and his bullshit “secret plan to end the war” which was transparent baloney meant to win votes of those uncomfortable with the notion of withdrawing from Vietnam while at the same time being tired of it. (brings to mind John McCain’s recent claim to have a plan to end the conflict in Iraq, harumph).
But his administration was great measured by its environmental and conservation accomplishments.
He’d be tarred and feathered by today’s party. And my own state’s Tom McCall was, in essence, tarred and feathered by the Reagan-era rabid right who’d taken over the Oregon Republican party when he attempted to make a comeback and regain the governor’s office.
[Response: No more partisan politics - gavin]
8 July 2008 at 9:07 AM
OK, I sent an e-mail to one of the authors of the pH paper suggesting that they might like to go a bit further with the general and interested and worried public : worried because the timelines keep getting truncated.
How about posting something on realclimate, I suggested.
I am particularly interested in the relationship of muck in the atmosphere to acidity in the oceans.
I dont much like 1 degree temperature rise (goodness gracious all that energy) in 100 years let alone 2 degrees but the oceans in 40 years?
Any smart scientists out there to help Joe Public and me?
8 July 2008 at 9:26 AM
Gavin,
You state that the increased take up in the oceans of human-released CO2 is rapidly increasing the acidity (lowering the pH) of the oceans. I understand the pH of the ocean had dropped 0.1 units in the period between 1750 and 1994, and that the current pH of the ocean varies from about 7.9 to 8.4. What data support your contention that the oceans are acidifying rapidly?
[Response: Direct measurements of ‘rapid’ (this is on a geological timescale) acidification, and a sufficient understanding of ocean seawater carbonate chemistry to know why, plus the almost certain continuing increase in atmospheric concentrations of CO2. See the wikipedia article for references. - gavin]
8 July 2008 at 9:58 AM
I’m not sure whether this was sarcasm or not, but just in case… Current ocean species have spent hundreds of thousands of years evolving under a certain range of ocean pH. If that pH suddenly plunges, there will absolutely be a shakeup of the various ocean ecosystems, as different species have different responses to increased acidity.
8 July 2008 at 10:21 AM
Just a quick (and probably irrelevant) clarification: I was using a common figure of speech and meant no denigration of real Softball. The fastest and best pitcher of any kind of ball, Eddie Feiner, threw softballs
8 July 2008 at 10:23 AM
It seems that one important response to shoddy science reporting is to contribute letters to the editor. They might set a portion of readers straight, as well as demonstrate to the newspaper staff that there are people paying attention to the accuracy of their science stories.
8 July 2008 at 10:24 AM
For purposes of legislative action, dire rhetoric is not usually all that effective because everybody cites worse case scenarios for every issue and legislators get used to dismissing it. Environmentalists have cried wolf more than most and that has given opponents a lot of ammo and leverage.
To quickly get rid of an apparently dangerous product like NF3, it is necessary to show the practical alternative. The car companies got a reprieve for several years on taking asbestos out of brakes because they claimed that the alternatives were unsafe (they weren’t, but it took time and effort to show that). VOCs from auto paint shops were a demonstrable health and environmental harm on many levels but lawmakers had to actually see that water-based paints and drying sheds were a viable alternative before they pulled the trigger.
I know from conversation with lobbyists, hill staffers and members over the years that consumer and environmental advocates are often ineffective because of compulsive self-righteousness and a strange pride in economic ignorance. Taking the position that everyone who disagrees is both immoral and stupid is rarely a winning tactic in any social setting.
I am not a chemical engineer but I assume there is probably an alternative to NF3 or a way to create closed process for vapor collection that could be mandated, probably even with express industry cooperation in formulating the details. When the choices are concrete, the costs known and the rhetoric deflated, things can get bi-partisan in a hurry.
8 July 2008 at 10:28 AM
Lordy lord lord, a great initial post and most every response is either tangential, a digression, or from another planet. Focus, people.
Gavin, you asked for a reference, here’s one — NF3 was a trivial chemical a few years ago, it’s becoming widely used very quickly.
Here’s why:
http://www.icis.com/Articles/2008/03/24/9109896/strong-photovoltaic-and-electronics-sectors-support-nitrogen-trifluoride-silane-and-ammonia-demand.html
8 July 2008 at 10:28 AM
Wasn’t the recent G8 result a “loose” goal, not a commitment? Wouldn’t such agreements mean more if they include China and India?
8 July 2008 at 11:00 AM
A sandbox 101 question: What is it that makes methane and others “much more powerful” greenhouse gases? Is it because their internal makeup allows considerably more IR absorption, molecule for molecule? Or is it because they absorb in bands like the window that are “virgin territories”? For example if we had no GHG in the atmosphere, then added say 50ppm of both CO2 and CH4, which gas would contribute more toward warming? Or is it related to the relative lifetime of the various gases? Or some combination?
[Response: All of the above. Different bands are differently absorbed depending on what the resonance is (vibrational, stretching etc.) and that depends somewhat on the strength of the bonds (which is obviously molecule specific). Concentration matters a lot - absorption is linear at very low concentrations and flattens out to logarithmic at higher values. And overlap is really important. If a molecule absorbs in the atmospheric window region, it is much more important than one that overlaps with water vapour. - gavin]
8 July 2008 at 11:02 AM
And an even more holistic approach would include (aside from all the effects from GW and GHG releases), the various other harms from doing the things that entail GHG releases; for example:
1. the other, more local pollutants from driving I.C.E. cars & their harms;
2. the money lost from not being energy/resource efficient/conservative, which at the macrolevel weakens our economy (never mind threats to the economy & livelihood from GW harms)
3. the health benefits lost from driving rather than cycling & walking.
4. increased crime because people drive rather than walk or cycle (there was a study that neighborhoods with heavier pedestrian and cycling traffic experienced less burglaries).
5. the physical/psychological stress of commuting long distances, bec one chose to live far from work, when closer comparable houses were avaiable, plus the lost family time, leading to various family dysfunctions….
6. War and conflict to secure our resources
7. Destruction of rainforests to get the bauxite for aluminum coke cans, bec we didn’t recycle our cans (which saves 95% energy & reduces GHGs).
And so on.
Of course, to be fair, we must balance harms against benefits to some extent (as long as it’s not a case of “I beneift, others are harmed”).
But in cases of desired benefits that entail harms, we should be looking for harmless or less/least harmful alternatives. This has not been done enough, since the industry-gov-media-military complex, focused and dependent on oil/coal profits, sort of makes it difficult for us to perceive problems they don’t want us to perceive, like GW and its many, many ramifications, and difficult to work on solutions (I’m still waiting for my plug-in-hybrid).
8 July 2008 at 11:03 AM
Pat N. at #14:
‘The fault for climate change having been “well below the radar of the public at large” for decades has been with NOAA National Weather Service (NWS) headquarters, NWS weather and NWS river forecast offices - not with the media and others not “finding just these kind of resonances”.’
It would appear that politics has played a part in what you report. But politics (and big money) has probably also played a part in how science is reported through the media and in the very selection of those who write for and appear in the media stories about climate change.
To borrow a phrase, this is the politics of minds suffering from ‘Nature Deficit Disorder’. Education can help stamp out this ubiquitous disease.
8 July 2008 at 11:13 AM
> How can those species be under threat when they have survived
Many did not, as you’d know if you looked it up. Rates of change….
8 July 2008 at 12:01 PM
In relation to the article, the Plasma TV’s have NF3. What do we know of NF3 and in technical matters what other choices do consumers have? In a greener ethical matter, don’t all companies find this as a concern? If these are being sold in the market at a higher demand rate, do we even have to think about the greatest number of the greatest good of everyone trying to buy into the companies products of plasma TV’s? I think so. This happens to be a main focus and a larger issue that should be discussed to the manufacturers. I believe that the research that has been brought up to this matter should be open for the public to learn and understand the information given.
8 July 2008 at 12:10 PM
re #17 Abbe Mac
You have to go back an awful long way to get atmospheric CO2 levels that are that much higher than current ones. Around 20 million years. That’s a very long time even on evolutionary time scales (humankind has only been around for around 200,000 years and the tree-dwelling apes from which the h-ominid line descended were around about 10 million years ago).
It’s the rates of change that are important. The current set of sea-dwelling creatures, and specifically calcite/aragonite-fixing species, have evolved under conditions of relatively constant or extremely slowly changing ocean pH, and so have a relatively limited som-atic adaptability to changes in ocean pH. Ocean pH just doesn’t change much on the many 1000’s of years time scale (barring catastrophic events). So these creatures are rather sensitive to what seem to be relatively small changes in pH of only a few tenths of a pH unit (remember the pH scale is a logarithmic one). This is easily demonstrated in the laboratory.
So the answer to your question “How can those species be under threat when they have survived much higher levels of CO2 in geological past?”….is that they haven’t survived much higher levels of CO2 in the geological past. Either their evolutionary predecessors were adapted to higher CO2 levels in the past, or (as happened during some of the major extinction events) they didn’t survive the insults (raised global temperatures/ocean acidification etc.) of greatly enhanced atmospheric CO2 concentrations..
..that’s the concern…
8 July 2008 at 12:44 PM
I think this goal implicitly assumes that (a) methane clathrates will not be problem, (b) CO2 & methane release from melting permafrost will not be a problem, and (c) a melting of 50% or more of the Greenland Ice Sheet is something we can adapt to. While it’s still possible that these three assumptions will turn out to be true, the impact of one or two of them being wrong could be awfully high ….
As for ocean acidification, this goal seems likely to cut the rate of acidification by about half. Ocean acidification is like global warming in that zero CO2-emissions are a prerequisite to a turn-around.
8 July 2008 at 1:00 PM
The industrial use explained (see also the link I posted earlier which leads to much on industrial volume and production):
“… forming an amorphous silicon nitride (a-SiN) deposited film … N-supplying raw material gas … examples are nitrogen (N2), ammonia (NH3), hydrazine (H2 NNH2), hydrogen azide (HN3) and ammonium azide (NH4 N3). Besides these, nitrogen halide compounds such as nitrogen trifluoride (F3 N) and nitrogen tetrafluoride (F4 N2) can be used. …”
http://www.patentstorm.us/patents/6712019/description.html
Forewarned:
“… if the chemical industry had developed organobromine compounds instead of the CFCs … then without any preparedness, we would have been faced with a catastrophic ozone hole everywhere and at all seasons during the 1970s, probably before the atmospheric chemists had developed the necessary knowledge to identify the problem and the appropriate techniques for the necessary critical measurements. Noting that nobody had given any thought to the atmospheric consequences of the release of Cl or Br before 1974, I can only conclude that mankind has been extremely lucky, that Cl activation can only occur under very special circumstances. This shows that we should always be on our guard for the potential consequences of the release of new products into the environment.”
Time to accept the precautionary principle?
http://nobelprize.org/nobel_prizes/chemistry/laureates/1995/crutzen-lecture.pdf
8 July 2008 at 1:11 PM
Rod B,
I’m going to quote a couple exerpts from raypierre’s climate book, and this is partially in line with what gavin said (particularly the fact that methane is stronger on a molecule-by-molecule basis because of lower background concentrations), but I’m not so sure it is in 100% agreement:
…………………….
//”There is, however, a widespread misconception that methane is in some sense an intrinsically better greenhouse gas than CO2. A few simple calculations will serve to clarify the true state of affairs….
The common statement that methane is, molecule for molecule, a better greenhouse gas than CO2 is true only for situations like the present where methane is present in far lower concentrations
than CO2. In this situation, the greater power of a molecule of CH4 to reduce the OLR results simply from the fact that the greenhouse effect of both CH4 and CO2 are approximately logarithmic in concentration. Reading from Fig. 4.35, we see that for methane concentrations of around 1ppmv, each doubling of methane reduces OLR by about 2W/m2. On the other hand, for CO2 concentrations near 300 ppmv, each doubling of CO2 reduces the OLR by about 6 W/m2. Hence,
to achieve the same OLR reduction as a doubling of CO2 one needs three doublings of methane, but since methane starts from a concentration of only 1ppmv, this only takes the concentration to
8ppmv, and requires only 7/300 as many molecules to bring about as was needed to achieve the same reduction using a doubling of CO2. Equivalently, we can say that adding 1ppmv of methane yields as much reduction of OLR as adding 75ppmv of CO2…..
If methane were the most abundant long-lived greenhouse gas in
our atmosphere, and CO2 were present only in very small concentrations, we would say instead that CO2 is, molecule for molecule, the better greenhouse gas. “//
………………..
Hope that helps.
8 July 2008 at 1:15 PM
And there are other ramifications from our GHG emissions. (I’ve just been reading Mark Bowen’s CENSORING SCIENCE: Inside the Political Attack on Dr. James Hansen and the Truth of Global Warming.)
I also think we should reduce our GHGs, bec:
They cause GW, which leads to scientists finding out, which causes lots of politicos to lie, cheat, deceive, and do other dastardly deeds in their attempts to cover up, censor, and distort the science, which may cause them to end up in a much hotter place than a globally warmed world. At the very least it increases cynisim toward government (and toward industries which fund the gov and media, and hire the politicos after/before their gov jobs), which feeds into increasing societal demoralization. Not to mention, helps thwart action to address GW — both bec the public isn’t getting the truth and bec they’ve been demoralized by such cover-ups and distortions.
8 July 2008 at 1:24 PM
The article linked in #13 is paroting the nonsense from Vincent Gray, who worked in the coal industry (and thus must not have a “vested interest” according to the article) and has never published anything about climate change, and basically knows nothing about climate change in general. He is one of those people who uses the title “expert reviewer of the IPCC” to claim some kind of qualifications, when, of course, anyone can be an expert reviewer.
The Canadian Free Press article is talking about the second order draft of chapter 9, not the first draft, and it doesn’t take much thought to realize that the first draft is going to have more comments than the second. The reason why 60% of the reviewer comments were rejected is because 50% came from one person, Gray. And the reason why they were dismissive is because his comments were incompetent. He has around 70 comments asking not to use the word “anthropogenic” and similar word changes. Other comments were basically wild declarations with no supporting evidence.
Anyone who doubts this can read the comments for themselves and search for Gray’s name:
http://ipcc-wg1.ucar.edu/wg1/Comments/wg1-commentAgree.html
8 July 2008 at 2:28 PM
Re # 17 Abbe Mac:
‘the scientific truth is being severely compromised by scare stories about ocean acidifcation. How can those species be under threat when they have survived much higher levels of CO2 in geological past?’
Why don’t you read the scientific literature on ocean acidification and find out for yourself? Then, please come back and tell us who is compromising the scientific truth. The following will get you started:
Impacts of Ocean Acidification on Coral Reefs and Other Marine Calcifiers (NSF, USGS, NOAA) http://www.ucar.edu/news/releases/2006/report.shtml
Ocean acidification due to increasing atmospheric carbon dioxide (Royal Society, UK)
http://royalsociety.org/document.asp?id=3249
Evidence for Upwelling of Corrosive “Acidified” Water onto the Continental Shelf
Richard A. Feely, Christopher L. Sabine, J. Martin Hernandez-Ayon, Debby Ianson, Burke Hales
Science 13 June 2008: Vol. 320. no. 5882, pp. 1490 - 1492 DOI: 10.1126/science.1155676
http://www.sciencemag.org/cgi/content/short/sci;320/5882/1490
You might also check out NOAA’s Pacific Marine Environmental Laboratory Carbon Dioxide Program Ocean Acidification website: http://www.pmel.noaa.gov/co2/OA/
For more general discussions of this topic, check the Wikipedia reference Gavin provided in # 20, or, this article by a couple of the leading scientists studying ocean acidfication:
Carbon Dioxide and Our Ocean Legacy, by Richard A. Feely, Christopher L. Sabine, and Victoria J. Fabry http://www.pmel.noaa.gov/pubs/PDF/feel2899/feel2899.pdf
8 July 2008 at 2:44 PM
The Carrot (16) — Suppose we found some means to rapidly remove excess CO2 for the air. Then the shallow ocean would degas to follow along, lowering pH. The CO2 already committed to the deep ocean will be there still, for a long, long time.
That’s my amateur take on it.
8 July 2008 at 3:16 PM
As an emissions market analyst, I spend endless hours scanning every article that pops up on Google when you search for the words “greenhouse gas.” For all of the occasional slightly off-topic digressions, it was truely refreshing to read a genuinely intellectual, scientifically literate discussion on the topic. I will definitely come back to this site when I need to feed my brain something healtier than the rubbish that passes for journalism these days.
8 July 2008 at 3:29 PM
RE: Greenhouse gases other than CO2
Is there any discussion of a regulatory framework to control the use of volatiles that have “bad” IR absorption spectra? In other words, it seems that industrial chemicals could be quantitatively ranked based on how well their IR absorption spectra overlap with that of H2O. This could be coupled with the lifetime of the gas in the atmosphere. The worse this coupled ranking, the more tightly the chemical would be regulated. That would effectively price poor “greenhouse gas” performers out of the marketplace.
Given the vast number of volatile chemicals in use in the world, such an approach would at least provide a general means for judging the use of these chemicals in industry.
8 July 2008 at 3:44 PM
Thanks Gavin for trying to keep politics to a minimum.
8 July 2008 at 3:51 PM
Re #38, its the speed at which it is hapenning I believe is a major factor, 30x previous events.
8 July 2008 at 3:57 PM
Previous response:
“How can those species be under threat when they have survived? Many did not, as you’d know if you looked it up. Rates of change…”
Those that did survive still have the genes left over from more acidic times. The phenomenally fast reproduction rate of most of these organisms ensures that they can adapt to changes.
Nature is pretty impressive. Don’t trust me though I believe in life on Mars.
8 July 2008 at 4:05 PM
Re #39
Did you mean “Then the shallow ocean would degas to follow along, raising pH”?
When CO2 dissolves in water it equilibrates with a hydrated form (H2CO3) which dissociates into bicarbonate and carbonate according to the pH:
CO2(air) {- - - - } CO2(aq) (+H2O) {- - - -} H2CO3 {- - - -} HCO3- + H+ {- - - -} CO3- - + H+
where {- - - -} represent reversible arrows (equilibria)
Knowing the total hydrated CO2 concentration, the concentrations of carbonic acid (H2CO3), bicarbonate (HCO3-) and carbonate (CO3- -) are easily calculated since the pKa’s defining the various equilibria are known.
So the pKa’s (the pKa is the pH at which there is 50% of each species on either side of any of the individual equilibria are):
H2CO3 {- - - - } HCO3- + H+ (pKa = 6.4)
HCO3- {- - - - } CO3- - + H+ (pKa = 10.3)
one can see that at pH 7.5 (sea water-ish) there is very little carbonate and most of the hydrated CO2 is in the form of bicarbonate
[the actual proportions of the species can be calculated from the Henderson-Hasselbalch equation:
pH = pKa + log ([base]/[acid])
so for the carbonate (base)/bicarbonate{acid) equilibrium:
[carbonate]/[bicarbonate] = 10^(pH-pKa)
and at pH 7.5 [carbonate]/[bicarbonate} = 10^(-2.8)
which is about 0.016]
I believe that this is the problem for ocean species that use carbonate to build their skeletons/shells. There is already a limited amount of carbonate in the oceans due to the high pKa of the bicarbonate-carbonate equilibrium, and as the pH drops the equilibrium is shifted even further away from the already very small dissociation of bicarbonate to carbonate.
Note that if CO2 were to “out-gas” from the oceans the equilibrium would be pulled in the direction of de-acidification (since bicarbonate needs to be protonated before it can dissociate into CO2 and H2O).
Interestingly this identical CO2-carbonic acid-bicarbonate-carbonate equilibrium maintains the homeostatic pH in our blood (pH 7.4)…a relic of our evolutionary deep oceanic past.
8 July 2008 at 4:22 PM
Re #20
You state that the increased take up in the oceans of human-released CO2 is rapidly increasing the acidity (lowering the pH) of the oceans. I understand the pH of the ocean had dropped 0.1 units in the period between 1750 and 1994, and that the current pH of the ocean varies from about 7.9 to 8.4. What data support your contention that the oceans are acidifying rapidly?
I hope you realize that the pH scale is logarithmic?
A change from 8.1 to 8.0 is a rise in hydrogen ion concentration of ~21%.
Re #44
Why do you assume that the acid resistance genes remain, particularly in an organism with a fast reproduction rate?
8 July 2008 at 4:30 PM
So this is what I sent to Mr Zeebe this morning (CET).
“Dear Mr Zeebe
I read ScienceDaily’s report on your work following up from a link on realclimate.org.
I understand the implications of ocean acidification but it is the first time that I have seen easily understandable numbers.
What interests me are your forecasts for pH changes by 2050 on the usual global warming scenarios. It wasnt clear from Science Daily’s report what the basis for your upper range forecast of 0,35 is.
I have posted a question to Mr Schmidt on the realclimate site but I wondered if it would help if you or one of your colleagues could yourselves post further explanatory information.
Best regards and dont weaken
Eachran”
Now, I am not a professional scientist but I am thinking about it even at my advanced age, but I would like to know what the number is and why.
This is the same issue as sea level rise or sea-ice extent or temperature rise, or the recent discussion about probability density functions.
It all boils down to the same thing : what is the number.
I posted on ice sheet mass balance and sea level rise on this very point and eventually two posters offered something.
My background is science, social sciences, and law and when I used to do law I worked with some pretty smart people in the profession. My instructions to them were, I am never going to sue you because if a decision is made it is my decision.
So all you scientists out there, there’s a challenge, no more ifs and buts or maybes or perhaps. I wont sue you.
What’s the number on pH by 2050 and why, and what are its implications?
I would add that I am impressed by Messrs Annan and Connelly for putting their money where their mouths are on climate issues.
8 July 2008 at 4:36 PM
#44 Sean:
[”Those that did survive still have the genes left over from more acidic times. The phenomenally fast reproduction rate of most of these organisms ensures that they can adapt to changes.”]
Not really. I don’t think that’s a supportable assertion without some evidence in its support! It’s more likely that the absence of selection pressure (more acidic oceans) will have resulted in the loss of the acid-adaptated genotype. Unless organisms have som-atic physiological adaptability (of the sort that lets us humans adapt to variations of altitude through the adjustment of the oxygen affinity of haemoglobin, for example) it’s unlikely that evolutionary adaptation could occur sufficiently quickly to allow adaptation to rapidly acidifying oceans..
…so it’s a question of time scales again. If atmospheric CO2 concentrations were to carry on increasing at current rates for another 100 years or more it’s rather likely that a large number of oceanic species would succumb, however “phenomenally fast” the little critters tried to reproduce. One/two hundred years is likely to be far too short a period for adaptive evolutionary responses, and the situation would be more akin to the previous extinction events in Earth’s history, many of which are associated with raised greenhouse gas levels/warming/ocean acidification/anoxia etc.
8 July 2008 at 4:44 PM
From an expert’s point of view, was the earth in a thermal equilibrium with the incident flux of sunlight before the industrial revolution?
8 July 2008 at 5:44 PM
What was the PH of the oceans at the time the carbonate-based life forms of Trilobites and Ammonites totally dominated the oceans and CO2 levels were 4,000 to 7,000 ppm?
8 July 2008 at 6:01 PM
John Lang: Trilobites and ammonites did not live at the same time, except during the Late Paleozoic when the trilobites were few and very much on the decline before their total extinction 245 milion years ago. Also trilobite carapaces aren’t necesssarily made of carbonate. Ammonites became dominant in Mesozoic oceans after the trilobite extinction.
8 July 2008 at 6:03 PM
Chris (45) — Yes. Thank you for the correction and the amplification.
8 July 2008 at 6:15 PM
#49 Aaron:
You can save the RC folks some time by rephrasing your question as what you already believe. I’m hazarding a guess that your point is “Well, the earth has experienced periods of non-equilibrium in the past, so what’s wrong if it isn’t in equilibrium now?”
Once you’ve done that, somebody can pipe up with the answer, probably to the effect that avoidably putting the system out of equilibrium in a way that will cause it to restabilize at a sub-optimal point is undesirable. I’m not I’m expert, but that’s probably the general gist of your “answer”.
8 July 2008 at 6:29 PM
A lot of the press reports on NF3 were confused, in the sense that they focussed mostly on flat panel displays, and thought the mention of plasma had something to do with plasma displays…
Plasma etching is a step in semiconductor manufacturing, and is different from the “plasma” in plasma displays.
NF3 is one of several choices used with CVD (Chemical Vapor Deposition) processes in general, i.e., in products that include:
- microprocessors, DRAM, etc
- flat-panel displays
- photovoltaic solar cells
To be clear, it’s one of the substances used in the manufacture of the products, it’s not *part* of the products (and better be long gone before the product ships), and actually, flat-panels may well be the lesser of uses.
As to why it’s used (it’s only one alternative), see Gas World, which says:
“NF3 is used as a chamber cleaning gas in the manufacture of semiconductors, flat panel displays and other electronic devices. When compared with competing products, NF3 offers customers significant reductions in emissions, throughput increases of up to 30%, longer chamber life and faster clean rates.
…
Nitrogen trifluoride is also used in the plasma and thermal cleaning of CVD reactors, while it is used as a source of fluorine radicals for plasma etching of polysilicon, silicon nitride, tungsten silicide and tungsten for example.
…
Although semiconductors remain the principal driver for electronic specialty gases, increased interest in photovoltaics is adding to the push.
Electronic gases are needed in thin-film deposition, such as chemical vapour deposition (CVD) or physical vapour deposition (PVD), technologies used to make a semiconductor or a photovoltaic cell.
The three major gases used in semiconductors, liquid crystal displays (LCDs) and photovoltaics are nitrogen trifluoride (NF3), silane (SiH4) and ammonia.
Demand for electronic gases in the semiconductor and solar cell industries continues to outpace global GDP growth by more than two times. In traditional semiconductor segments such as microchips and flat panel displays, market researchers expect sales growth of around 8% per year between now and 2010 – and for the solar segment, the annual forecast lies at around 30%.
Experts anticipate that from 2012, photovoltaic producers will spend more on gases than flat-screen manufacturers, and from 2017 they are even set to overtake the chip sector.
Although only a handful of different gases are used in solar-cell manufacturing – in comparison with more than 20 for semiconductors – the volumes required are significantly greater.”
SO, as usual, one must be careful with popular press. They whacked flat-screens, which are second to semiconductor chips, and will likely be third to PV cells.
I haven’t seen the full Prather article, but:
1) WE certainly do need to be measuring this.
2)However, if there’s one place where chemicals are *very* carefully controlled, it’s a semiconductor fab, thank goodness. Equipment vendors (Applied Materials, etc) and fab operators certainly need to pay attention to keeping this under control or (maybe) finding alternatives, but it may be a potential problem reasonably kept under control. Again, fabs are at least used to working with witches’ brews of nasty chemicals.
8 July 2008 at 6:42 PM
Re #29
What you said is probably true, but politics (and big money) does not explain why NWS
deliberately kept climate change below the radar screen during the Clinton/Gore administration.
8 July 2008 at 6:54 PM
Re # 45 Chris
“… this identical CO2-carbonic acid-bicarbonate-carbonate equilibrium maintains the homeostatic pH in our blood (pH 7.4)…a relic of our evolutionary deep oceanic past.”
As you seem to be quite familiar with aqueous carbonate chemistry, I’m surprised you would end with a statement such as that. The CO2 buffering system in our blood doesn’t involve carbonate to any significant extent, as there is little carbonate at pH 7.4 (as you noted, the HCO3-/CO3= reaction has a pK around 10.3) . Second, the pH of 7.4 is maintained largely by amino acids, such as histidine (mostly in proteins and peptides), having a pK in that range; the pK for CO2/bicarbonate is a full pH unit lower (again, as you noted). Our blood chemistry is no doubt a carry over from our piscine ancestors, but most fish have a blood chemistry (i.e., concentrations of specific ions) very different from that of seawater. However, the CO2/bicarbonate buffer system is a fundamental property of aqueous systems, period - it is not restricted to seawater.
8 July 2008 at 7:20 PM
On the subject of ocean acidification, how much CO2 gets dissolved in the oceans on a day to day basis? Also, the Henderson-Hasselbalch doesn’t really apply here because there are other organism that use CO2 for other physiological functions, namely photosynthesis. Even if it was, you would first need a rough estimate of the amount of base to CO2 as an acid to know the effect of the unused CO2. I’m also guessing that most of that base is in high concentrations in reefs and other places where life is most likely found. Since CO2 is just as likely to dissolve anywhere in the ocean, even a large amount of CO2 dissolved would have little impact since its concentration will be much diluted and many orders of magnitude smaller than the concentration of the base say in a crab’s shell or a coral reef. Diffusion is a powerful process.
8 July 2008 at 7:26 PM
#53 Doug
There are stable fluctuations from equilibrium and there are unstable ones. The question is whether or not the earth existed in a stable equilibrium before the industrial revolution. Also, how would one tell if an equilibrium is stable or not other than the usual stat mech definitions of compressibility and heat capacity? I know that there is an attractor the atmosphere, but can the atmosphere venture far from this point in phase space? If so, how far?
8 July 2008 at 7:43 PM
#53 Doug
The question does not have an answer as far as I know. I would not have asked it if I thought I had the answer. I know that some fluctuations in a grand canonical ensemble, like the earth, are stable, meaning that they will return back to the same equilibrium state after the fluctuation. That’s how one knows that as you increase the amount of energy you increase the temperature. It is a stability requirement of the ensemble. I just wanted to know if this picture is applicable to the earth system with a solar sunlight bath reservoir in equilibrium. Its really a statical thermodynamics question.
8 July 2008 at 7:56 PM
Re the response to #11: Gavin, I have been trying to get a better understanding of the lifetime of methane than the usually quoted ten years. But can you please explain your statement “For CH4, 12 years for the perturbative half-life (longer than the ~8 year residence time) is reasonable. How can half-life be longer than residence time?
[Response: CH4 has what is called a feedback on it’s own lifetime. CH4 loss is controlled by the OH- concentration, but if you increase CH4, you use up OH-. The residence time is the total amount of CH4 divided by the loss rate (roughly 8 years), and if the loss rate was constant, then perturbations would decrease with an 8 year time-scale. But since the loss rate actually goes down if you increase CH4, that means that perturbations last a little longer than that (roughly 12 years). There’s more discussion (taken to extremes) in Schmidt and Shindell (2003). - gavin]
8 July 2008 at 8:04 PM
The article says 4,000 tonnes of NF3 were produced last year and the CO2 equivalent of NF3 is 17,000 times that of CO2.
While those numbers sound shocking, the CO2 equivalent of current NF3 production of 68 million tonnes should be compared to the CO2 production amounts of roughly 40 billion tonnes (ie, this is 1,000 times smaller than CO2 or a forcing of let’s say 0.0017 W/m2)
8 July 2008 at 9:37 PM
Gavin, Chris C., thanks for the help.
8 July 2008 at 11:14 PM
One of the comments claimed the warming effect of the NF3, was similar to that of a single coal plant. If I were to take that statement at face value then the impact of this chemical is pretty small, in fact probably very much less than any CO2 released by the production of the power used by those displays. If that is the case, then this chemical needs a small amount of monitoring just in case either its effect has been grossly underestimated, or its usage grows dramatically. It hardly seems like an issue of general concern.
9 July 2008 at 3:13 AM
The atmosphere holds 760 gigatons of CO2. Man emits about 6 gigatons of CO2. The total emissions from all sources are about 200 gigatons (I have seen numbers as low as 150 gigatons so clearly the level of understanding of the carbon cycle is poor), and each year there is a net uptake of about 3 gigatons. So 98.5% (98%) of all CO2 emissions are absorbed into the various sinks. How exactly is mans CO2 emissions due to energy consumption contributing to the 3 gigaton uptake. Shouldn’t our share be 3% (or 4%) of this, or 0.09 (0.12) gigatons? And how does CO2 stay in the atmosphere for 100 years or more when 30% (20%) of CO2 in the air is removed from the air each year. Seems the half life would be 3-5 years?.
Not saying man is not affecting things, and not saying CO2 is not responsible for part of the warming, or that there is not any warming. Deforestation, urban island effects, agricultural practices and other pollutants certainly must contribute to whatever changes man is responsible for, and natural variation in climate may be a factor. But I want to stay focused on man made CO2 from fossil fuels and why it takes the heat for global warming.
[Response: Because it has increased ~100ppm (37%) over pre-industrial levels - all of which is due to human emissions. Your calculations are wrong because you are neglecting that the ocean/land sources are almost in balance with the sinks, but that the real sink out of the land/atmosphere/upper ocean system is the flux into the deep ocean, which is much slower. Think of it like a bath tub that has a tap turned on and a small drain and has reached a stable level. In the bath there is someone sloshing the water from one side to the other. Now you come along and pour in some buckets of extra water - the average level will rise depending on how quickly the small drain responds, but it is doesn’t depend on the sloshing at all. - gavin]
9 July 2008 at 4:50 AM
Re #56:
Chuck: yes, you’re right that the bicarbonate - carbonate pKa is too high for this equilibrium to make a significant contribution to pH buffering in blood. It’s almost exclusively the carbonic acid-bicarbonate equilibrium that is involved. I used the entire equilbrium (carbonic acid-bicarbonate-carbonate) since, if there’s any hydrated CO2, the full equilbrium is represented, distributed amongst the various species according to the pH (it’s just that there is a minimal contribution from dissociation of bicarbonate to carbonate at blood pH).
The carbonic acid - bicarbonate equilibrium is an important pH system in blood ‘though, and especially so since the blood is continually coping with changes in CO2 concentration. So just in the same way that outgassing of CO2 from oceans results in a rise in ocean pH, so the “outgassing” of CO2 from blood (through the lungs) “pulls” protons from the blood onto bicarbonate and raises the pH (and if the pH becomes too alkaline, bicarbonate is removed by the kidneys).
Interestingly, whereas the reversible hydration of dissolved CO2:
CO2(aq) + H2O == HCO3- + H+
is quite a rapid reaction (half life around 5 seconds) so that CO2 equilibrates between the air and ocean surface according to the temperature and atmospheric CO2 concentration (and ocean surface dissolved CO2 concentration -equilibration of which with the deeper ocean layers is limited by the physical mixing of surface and deeper layers presumably), this reaction is catalysed in blood by carbonic anhydrase resident in our red blood cells, each enzyme molecule of which can bind and hydrate 1 million CO2 molecules to bicarbonate every second.
The other buffering components of blood pH are proteins as you say (especially haemoglobin which binds protons), and also inorganic phosphate which has a pKa (6.8) closer to blood pH…
9 July 2008 at 5:22 AM
The Great Barrier Reef has proved to be an effective ‘hook’ here in Australia. A google news search gives you an idea. The turn-around in the average aussie’s attitude to climate change in the last couple of years has been nothing less than stunning, it and Iraq were the major factors in the recent election.
9 July 2008 at 5:50 AM
#44
As a geneticist I thought I should comment on adaptation in general to give a picture of what effect “strong” (whatever means strong) acidification could have.
Biological organisms have been shaped by their environment, are still shaped nowadays and will still be shaped tomorrow.
They are, in parallel, shaped by “random drifting” based on their ability to acquire changes (mutate).
So we have two forces that are specific for each organisms and even (but to a lesser extend) to each individual of a given species:
1) Speed of genetic changes (intrinsic, species specific & in more moderate way individual specific)
2) Speed on environmental changes (extrinsic, global, regional,…)
if genetic changes match environmental changes -> good you survive & proliferate
if genetic changes fit less well with environmental changes -> well you survive less and you know what ? it’s a competition ! so you should change yourself or the environment otherwise you’ll disappear.
So it is true that species and some individuals in these species may have kept or re-acquire a greater resistance to acidification allowing them to cope better with acidification changes.
It should also be noted however that there is even more species and individual that did NOT maintain such resistance or even became very sensitive to acidification. For example all these organisms that were spared from acidic environment for long (evolutionarily speaking) periods of time.
To simplify, the more brutal the change (evolution scale remember) the more species and individuals will be eliminated (strong selection), the slower the change the more species and individual will be maintained (weak selection).
I think corals (a lot of coral species but not all) are a good example of organisms that are sensitive to acidification. Many coral species may disappear, very few may survive and even expand reducing diversity until they drift to recreate a certain diversity.
But the stronger the acidification, the smaller the number of species that can survive and the smaller their possibilities to evolve (strong constraints limits possibilities).
Hope I haven’t been too much off-topic…
9 July 2008 at 6:34 AM
Aaron writes:
Yes, and on short time scales, it is now. If it weren’t, Earth would heat up or cool down, as required, until balance is restored.
We’re a bit out of balance now, and staying that way, because the amount of greenhouse gases in our atmosphere is steadily increasing. But to a first approximation you can model the Earth’s atmosphere very closely by assuming radiative equilibrium at top-of-atmosphere.
9 July 2008 at 6:46 AM
Somewhat off topic, but speaking of other greenhouse gasses, in this case ozone, Alastair Lewis was interviewed on the very pro-environmental National Public Radio show Living On Earth (see http://www.loe.org/shows/shows.htm?programID=08-P13-00027#feature2 ) broadcast this weekend. It was very upbeat on global cooling from tropical ozone depletion due to bromine and iodine, probably from sea spray. The following exchange was particularly interesting to me:
ELLERMAN: So I guess this is really gonna change our perspective on climate models and change the climate models?
LEWIS: Well it certainly shows that we need to keep an open mind, that actually there are some things out there in remote places that are pretty important, that we actually haven’t discovered or accounted for yet, that it’s not a completely done deal in terms of the chemistry of the atmosphere, that there are still some discoveries to come. Understanding how the climate works is still subject to big uncertainties so there are big processes that perhaps we haven’t discovered, or processes that we don’t understand accurately and we need to go to these places to really try
[Response: What you see is a journalist asking a seemingly important question and the scientist trying to get back to what they know about. There is no ‘global cooling’ from halogens above the ocean, since there is no reason to expect them to be changing. What this does is affect the background state for ozone in chemistry-climate models in some regions, which is likelyl to have little or no effect on changes in ozone due to increased emissions of precursors. It’s obviously better to get all these details in, but the whether this is ‘really gonna to change our perspective on climate models’ - the answer is no. - gavin]
9 July 2008 at 8:06 AM
O.K. I’m going to ask low-level question of the day.
T. Boone Pickens this week announced plans to set up (on private property, minimal governmental approval needed) a network of windmills to generate power. The radio show I was listening to this morning, Brad & Britt on WZTK in Greensboro (not a national show, and usually rather balanced. One of them is conservative and one is liberal, both have shown a lot of leaning towards environmental conservatism), they said the plan was to try to string enough power generation together to power 50 million households.
Will that amount of power generation reduce the production need enough for some of the other non-environmentally friendly power plants to stop producing so much polution? With the Majove desert solar projects, the current Hydro-electric and nuclear plants online and now the wind project, would that be enough to pull coal out of the equation? Or somewhat close?
(As was proven on another thread, I’m somewhat new to the game, so asking those who know to see if there might be some hope…)
Paul
9 July 2008 at 8:44 AM
#57 Aaron
Yes the Henderson Hasselbalch equation applies here. The H-H equation effectively defines the equilibrium distribution of the basic (proton acceptor) and acidic (proton donor) components (conjugate pair) of a titratable group (a buffer). So it can be used to calculate the ratio of carbonate/bicarbonate (or the absolute concentrations of these if the total buffer concentration is known, which I’m sure it is in the oceans - it’s around 27 mM in blood, of which nearly 26 mM is bicarbonate) in the oceans, in blood or in a bucket.
It doesn’t really depend on other organisms [if a photosynthetic algae uses a bit of dissolved CO2 this will have a tiny effect on the CO2-carbonic acid-bicarbonate-equilibrium, but this will just “readjust” (Le Chatalier’s principle) and (assuming the local sea pH doesn’t change), the equilibrium ratios of conjugate acids and bases (e.g. carbonic acid/bicarbonate) won’t change].
I’m not sure what you mean with:
[“Even if it was, you would first need a rough estimate of the amount of base to CO2 as an acid to know the effect of the unused CO2. I’m also guessing that most of that base is in high concentrations in reefs and other places where life is most likely found.”]
Notice that in the Henderson-Hasselbalch equation “base” means “basic component of the buffer”.
So in the equilibrium:
H2CO3 === HCO3- + H+ === CO3- - + H+
Bicarbonate is the “base” when considering the carbonic acid – bicarbonate equilibrium and is the “acid” when considering the bicarbonate – carbonate equilibrium. So I wonder if you are using the term “base” in the same manner that I, and Mssrs Henderson and Hasselbalch, are! Obviously carbonate is the most basic component of the buffer. So if that’s what you are referring to, I see sort of what you are saying with respect to the reefs/coral etc. However this carbonate is essentially “fixed” (as aragonite or calcite)..the carbonate in equilibrium with bicarbonate in sea water is dissolved carbonate. That’s not to say that the “fixed” carbonate (in shells and skeletons of sea creatures) isn’t also in “equilibrium” with the dissolved carbonate, and of course one of the problems of ocean acidification is that the shift in the carbonate/bicarbonate equilibrium even further towards bicarbonate enhances the leaching of “fixed” carbonate back into solution…..
…i.e. the shells of the poor sea creatures start to dissolve…
9 July 2008 at 9:10 AM
Aaron,
When we speak of nonequilibrium thermodynamics, we are really talking about near-equilibrium thermodynamics. There really aren’t great methods for treating systems that are far from equilibrium. However, most systems do not spend a significant proportion of time far from equilibrium, and this includes Earth. The concept of local thermodynamic equilibrium applies except right at the top of the atmosphere. The boundary condition is tricky, but can be handled.
9 July 2008 at 9:19 AM
Re #72, apart from Life itself perhaps which is far from equilibrium.
9 July 2008 at 9:28 AM
Am I missing something here? At home, I have copies of publications going back to the early 1980’s, which refer to the problem of increased oceanic acidification due to enhanced levels of atmospheric CO2. So why are certain sectors of the media only beginning to take notice of a “new” issue now?
This ought to be given more prominence; one of the main contentions in “The Great Global Warming Swindle.” last year, claimed that the oceans could be a net exporter of CO2 to the atmosphere, resulting from increased temperatures (entirely natural, of course) But if oceans are acidifying as a result of increased CO2 uptake, they logically cannot be a net exporter of CO2 back to the atmosphere.
Yet most people I have spoken to, on both sides of the divide, appear not to have even heard of the issue of acidification.
9 July 2008 at 9:39 AM
As for other factors contributing to AGW, let’s not forget all that carbon released by all the fires (800 currently in California alone) caused by the extra heat and drought caused by AGW. A vicious cycle that will probably snowball. And drought will unfortunately probably mean less regrowth of carbon-eating trees and more initially of dryland chaparral communities and giving way finally to desert conditions.
9 July 2008 at 9:46 AM
#71 Chris
But if the Henderson-Hasselbalch equation is applicable after accounting for the amount CO2 has been used to photosynthesize sugars, and concentration of base, from the definition in the equation (either single or bicarbonate), is much, much higher than the trace amount of CO2 that are dispersed throughout the ocean, based on an analysis that would like the Langmuir adsorption isotherm, how can these traces amounts of the acid (CO2) contribute enough to dissolve crabs’ shells which have a much higher concentration of the base? We are taking a small number and dividing it by a bigger number and then taking a log. That sounds like a very small number to me. Also, if there is more CO2 for more algae to make more sugar and then more algae, that puts more carbon to turn into carbonate by crabs and the like. So carbonate may not be truly fixed, but there are definitely competing processes. The question is, once these other factors are accounted for, production of new carbonate from more microorganisms and consumption of CO2 by said microorganisms, what does this do to the relative concentrations of both bases and CO2 at the point of activity?
#72 Ray
If the common practice is to treat the earth as a thermal system in equilibrium with a sunlight bath, what is a rough estimate for the absolute magnitude for the largest stable fluctuation in the internal energy of the earth? I would guess that this might be related to the square root of number of particles in the atmosphere as would be the case for a grand canonical ensemble, but I don’t if that is allowable with the different physical phases found in the atmosphere (i.e. gas, clouds and crystals).
9 July 2008 at 9:52 AM
Out of curiosity, how do we know that we’re not completely out of balance right now? In other words, what if temperature is rapidly increasing primarily because we’re not in equilibrium, regardless of whether green house gases continue to accumulate in the atmosphere? Can this scenario be discounted? If not, is there a reliable way to know when equilibrium should be expected to be reached?
9 July 2008 at 9:55 AM
I thought this was interesting new analysis on methane in the ocean
http://www.sciencedaily.com/releases/2008/07/080703113642.htm
It came out on July 4th, seems to be in the positive feedback progression.
From Article:
Although the implications for global climate change are still being studied, the warming and further stratification of the ocean seem likely to affect marine methane production. “This is a newly recognized pathway of methane formation that needs to be incorporated into our thinking of global climate,”
9 July 2008 at 10:51 AM
#77 Joseph
Using Kirchoff’s Law one can tell whether or not a graybody like the earth is near or far from equilibrium. This is done by related the amount of incident radiation from the sun is absorbed and how much the earth thereafter emits. If the ratio of these two factors stays relatively constant, which it has for the earth, then one can assume that the earth is pretty close to equilibrium. This is how greenhouse gases play a role in this drama. More CO2, CH4, H2O and other gases there are, the bigger the absorption and an increase in T. But so far, this has been a hard thing to measure so I would say that it is up in the air at best.
Also, it is very hard to push a system as big as the atmosphere far away from equilibrium. I would even say that the amount of CO2 we put into the atmosphere would not even make the internal energy of the atmosphere fluctuate enough to not have it come back to equilibrium some other way, but this is just a hunch. I mean , if we pushed the atmosphere so far from equilibrium, how have the last three very large volcanic events have not done the same in the other direction?
[Response: This is extremely confused. Kirchoff’s law says no such thing, the greenhouse effect is not a hard thing to measure and is not ‘up in the air’ in any sense except literally. Volcanoes do have large negative impacts on the TOA radiative balance but they don’t occur frequently enough to have cancelled out the increasing effect of GHGs (see here). - gavin]
9 July 2008 at 11:14 AM
Re pft @ 64: “The atmosphere holds 760 gigatons of CO2. Man emits about 6 gigatons of CO2.”
Out of date figures, human emissions are currently over 8Gt per year.
“The total emissions from all sources are about 200 gigatons…and each year there is a net uptake of about 3 gigatons”
That’s 3Gt of human generated CO2 (measuring just the C, again should be ~4Gt currently). As Gavin pointed out in his response, total natural emissions and uptakes by natural carbon sinks are roughly in balance, plus the sinks are also taking up roughly half of human emissions. Hence the rest of human emissions, ~4Gt, account for all of the annual increase of 2+ppm/yr.
9 July 2008 at 11:39 AM
# 76 Aaron
Chris was correct about the H-H equation - in its standard form, it relates pH, dissolved CO2 gas concentration, and bicarbonate concentration. If one of those values changes (e.g, bicarbonate is taken up by photosynthetic algae, or excreted by the kidney), the other two will change in a predictable way (once equilibrium is re-established, and assuming there is no change in temperature or salt content, which could alter the pK a bit).
Chris: The point I was actually trying to make (# 56), but didn’t make very well, was that the CO2-bicarbonate buffering system is an unavoidable consequence of life based on an aqueous environment in the cells and other body fluid compartments. The homeostatic mechanisms that keep our blood pH at 7.4 (and keep fish blood pH at 7.7-8.0, depending on the temperature) are, in large part, those that evolved to regulate the components of that buffer system, i.e., elimination of CO2 by ventilation of gills and/or lungs) and uptake or excretion of bicarbonate and H+ via ion transporters in gills and/or kidneys. Your statement seemed to suggest that it was the chemical buffering system that maintained homeostasis, whereas I would argue that the buffer system merely responds to changes resulting from physiological processes subject to feedback control; homeostasis is (usually) the result. In short, I was merely nitpicking a bit for the sake of clarity and accuracy. You obviously understand the physiology quite well.
9 July 2008 at 11:42 AM
Joseph, I’m not sure what you are asking? The climate is not behaving like a system far from equilibrium, but rather like an equilibrium system perturbed from that equilibrium by a forcing.
Aaron, I’m not sure that your question is a reasonable way to look at a dynamical system with components that interact on very different timescales. That’s sort of the problem Schwartz had with his overly simplified depiction of climate. But basically, the answer to your questions is that different scales of fluctuations will happen with different probability distributions on different timescales. That’s the noise. The thing is that none of the noise has a monotonically increasing character, so the longer the timescale, the more–on average–we expect to see trends due to CO2.
9 July 2008 at 11:54 AM
Re #69, the NPR interview of Lewis:
When I heard the interviewer ask that loaded question during the broadcast, I started yelling warnings at Lewis as I yell at characters in bad horror movies who are about to open the closet from which blood is dripping.
Lewis’s response was perfectly adequate for a listener who knows what Lewis knows. Unfortunately, he didn’t preface his response with a sufficiently simple and strong answer for listeners who are less in the know, or listeners who know incorrect things.
I certainly don’t blame Lewis. He was thinking on his feet, his answer was excellent for some audience members, and he seemed to be giving the interviewer the benefit of the doubt. Unfortunately, nowadays I think all interviewees on any topic that might remotely have a connection to climate change should prepare for interviews by preparing one short, strong, unequivocal, clear sentence about the relation of their topic to climate change. They should write that sentence on a note card that they keep in front of them during the entire interview, so they can read that sentence on a moment’s notice.
9 July 2008 at 11:54 AM
I apologise in advance for what I know is a bit off topic - even though it is very much connected with AGW. I am sitting here on an English summer day suffering the dismal drizzle dripping form a grey gloomy sky all brought on by a deep and slow moving mid-latitude cyclone (depression)that has hovered over Britain for near 48 hours. A seemingly endless succession of such depressions have sluiced their way across NW Europe this year - and indeed even the western Mediterranean has not been unassailed by damp and dripping depressions. I am recently back from Tuscany and Rome in not so Sunny Italy where one period the deluge was continuous in a Scottish Highlands sort of way for 36 hours. The dreary summers afflicting Ireland, Britain, France, Scandinavia and Benelux as well as Spain, Portugal and Italy are causing increased scepticism about the reality of global warming.
There is I believe, research that suggests that the higher temperatures associated with increased levels of greenhouse gases may be reflected in an increase in the intensity (though not the frequency) of tropical cyclones - hurricanes and typhoons etc. Presumably, deeper cyclones with higher winds and heavier rain would ultimately result from the warmer air of the present having a higher maximum possible absolute humidity than the cooler air of before AGW i.e. the warm air has a higher “capacity” for water vapour, than does cool air. When warm air rises and cools adiabatically, the water vapour condenses our, releasing latent heat, encouraging continued rising, cooling, and condensation under conditions of instability when adiabatic lapse rates are higher than the environmental lapse rate. In short, warmer air may provide more energy to the cyclone to result in higher windspeeds, lower barometric readings at the centre of the cyclones, and heavier precipitation.
Could such processes also be operating in mid-latitude depressions that develope over the west Atlantic and move north west to Europe? Is there any evidence that mid-latitude depressions/cyclones are more intense (and perhaps more frequent) than say 50 or 100 years ago? Does anybody know of any research that has looked into
1. Possible increases in pressure gradients within depressions
2. Increased mean windspeeds.
3. Increased intensity of precipitation.
4. Increased frequency of depressions.
5 Increased complexity of frontal systems and occlusions.
My thought is that global warming may actually increase uptake of water vapour from the oceans and in certain geographical areas - West Europe for example - result in increased cloud and storm, and possibly localised cooling relative to the rest of the globe.
9 July 2008 at 12:08 PM
Joeseph, #77:
As this RC article explains, our planet is indeed out of radiative balance, and the temperature increase is due to not being in equilibrium. This is primary evidence for global warming - and this imbalance is entirely due to human-emitted greenhouse gasses. And indeed, substantial warming remains ‘in the pipeline’, and if GHG levels froze right now, we would still experience about 0.6 C further warming.
9 July 2008 at 12:26 PM
Gavin, you’re right. The ratio is described does not have to equal a constant for there to be thermal equilibrium, it has to equal one. In the IR region, this is the case. Now for Kirchoff’s law to really make sense this has to hold true for all the parts of the em spectrum and I don’t know if this has been tested. If you know of data on the absorption and emission of radiation by the earth in regions like x-ray and gamma, please let me know. I would like to look at them. If you would like more information on Kirchoff’s law please see
http://en.wikipedia.org/wiki/Kirchhoff%27s_law_of_thermal_radiation
As for volcanoes, I was not suggesting that they could somehow offset the contributions of greenhouse gases by people. I was claiming that these large scale volcanic effects provide very large fluctuations to the internal energy of the atmosphere, modeled as a grand canonical ensemble. Despite these fluctuations the atmosphere is able to bounce back and return to the basically the same equilibrium position in a rather short period of time, much less than geological time. It would be interesting to see what the maximum absolute fluctuations in the internal energy would still allow the atmosphere to return to the same equilibrium state with the incident radiation from the sun and whether or not adding so much CO2 or other gas would provide this much of a fluctuation on what type of a time scale.
9 July 2008 at 12:27 PM
pft:
Leaf dies and rots. CO2 released.
Leaf grows. CO2 sequestered.
Unless we have fewer plants year on year (by, say, cutting them down…) this is a balance. That there are a quadrillion tons of leaves means nothing. They all grow back.
Now:
We extract the oil and burn it. CO2 released.
We ????
Ah. We don’t have a natural sink for this.
So even 1 ton of CO2 burned needs to be taken up by something else. And you need to PROVE this single ton is taken up because the default is “nothing”. you must prove your assertion to a skeptical crowd.
When we note that it is trillions of tons of oil, we have problems.
9 July 2008 at 12:35 PM
If I understand that graph correctly, there’s a clear trend in net forcing, which means we’re not in equilibrium, and getting further away from equilibrium.
How do we know that, even if GHGs stay at current levels indefinitely, equilibrium will be reached, say, at a 2 or 3 degree anomaly vs. an 8 degree anomaly? In other words, can an assurance be offered that the current level of disequilibrium is not much more catastrophic than normally thought?
Historically, it seems that an increase of 100 ppmv CO2 has quite a major impact on temperature (although I’m not sure to what extent that’s due to feedbacks).
9 July 2008 at 12:48 PM
Regarding the CO2 absorption or release question (posts 16, 39, 45, 46): the oceans absorb CO2 (check the NOAA numbers). Increasing atmospheric CO2 concentrations increase the air-sea flux, which has its most significant impact on the shallow surface waters. This causes increasing acidification in these waters due to the slow rate of deepwater formation, which would transfer the water with increased surface CO2 to the deep abyssal waters. Plus, the major impact is in the Pacific where carbonate saturation depths are shallow, but the significant transfer of water with increased TCO2 (and the associated carbonate system changes) is going to occur in the North Atlantic and the Southern Ocean.
Slowing down the rate of atmospheric CO2 increase would thus slow down the rate of the increase of the air-sea CO2 flux. Reversing the increasing atmospheric CO2 trend (we can dream) would also reduce the air-sea CO2 flux, but I’m qualitatively sure that even if it goes down to pre-industrial levels, the air-sea flux of CO2 would still be into the oceans. But it would be closer to balance with deepwater formation rates, so there would much less acidification of surface waters.
9 July 2008 at 12:57 PM
#76 Aaron
That’s very confused - you’re mixing up all sorts of unrelated concepts.
The Henderson-Hasselbalch equation simply defines the ratio of the acidic and basic components of a buffer according to the pH and pKa. Nothing more, nothing less. It defines the position of a physical equilibrium. It’s got nothing to do with what animals do with CO2, sugars and so on. We’re talking about how dissolved CO2 in the ocean that is hydrated to carbonic acid further partitions between its monobasic (bicarbonate) and dibasic (carbonate) forms, and how this affects the ocean acidity.
Carbonate-fixing animals in the sea fix various forms of carbonate (CO3- -) usually as CaCO3 (calcium carbonate, which in various forms like calcite and aragonite is the dominant component of shells/coral). The concentration of carbonate in sea water is small (around 230 umol kg-1 or 230 micromoles per kilogram of sea water), because the dissociation of bicarbonate to carbonate is not favoured in sea water (the equilibrium at the pH of sea water is almost 1000-fold in the direction of bicarbonate; see my post #45). As the pH drops further, due to increasing atmospheric CO2 concentrations, the equilbrium shifts even further away from carbonate towards bicarbonate. During the last 420,000 years through several glacial/interglacial cycles, it’s unlikely that the carbonate concentration dropped below 250 umol kg-1, so already the acidification of sea water resulting from our massive CO2 emissions has resulted in a very significant drop in the sea water carbonate concentration.
This follows directly from the straightforward physical equilibrium described in my posts #45 and #71. As CO2 dissolves and is hydrated in sea water, the carbonic acid releases protons acidifying the water and shifting the bicarbonate – carbonate equilibrium further in the direction of bicarbonate. The carbonate concentration drops.
It’s really as simple as that.
How problematic is this phenomenon? Potentially very problematic. The sea water carbonate concentration that was in the range around 310-250 umol kg-1 during the last 420,000 years (calculated from CO2 concentrations from the Vostock ice core), has been reduced to 230 umol kg-1. Experimental studies have shown that carbonate accretion (“fixing”) on coral reefs drops to zero or becomes negative (aragonite leaching back into the water as dissolved carbonate) when the carbonate concentration drops to around 200 umol kg-1. That’s expected to occur at an atmospheric CO2 concentration of 480 ppm.
These things can be calculated since they are simple physical equilibria. The effects on coral reef growth can be directly observed in field studies and experiments.
A useful acount of the effects of atmospheric CO2 emissions on ocean pH and coral reefs was published recently:
O. Hoegh-Guldberg et al (2007) “Coral reefs under rapid climate change and ocean acidification” Science 318, 1737-1742
9 July 2008 at 12:59 PM
re Paul (70), actually Pickens’ North Texas 200,000 acre wind power project will (hopefully) by 2014 generate 4000MWatts, which is estimated to handle 1,300,000 average homes — about the same as two large nuclear power plants. … at a cost of about $12B (which also includes some transmission lines and a separate water delivery pipeline). This is a bit bigger than the 2700MW wind farm in West Texas and way larger than the 300MW the State is planning for the Gulf of Mexico, but is said to be the largest (planned) in the world to date.
It’s curiously interesting since, as you probably know, T. Boone made his $billions over the last 50 years from oil and natural gas. It will be interesting to see if 1) he can pull it off (2 installed every 3 days over six years+ for the turbines alone in an area with virtually no infrastructure), and then 2) make any money off it (requires the continuing federal operating (tax) subsidy, e.g.)
9 July 2008 at 1:23 PM
@Thermodynamic equilibrium and earth
Maybe somebody can enlighten me,
I learned that for a macroscopic body in thermodynamic equilibrium all extensive parameters like pressure, volume, temperature, composition and number of molecules are independent of time.
I learned also that thermodynamic equilibrium requires detailed balance on a microscopic scale. This means per example for two black bodies in thermodynamic equilibrium that the incoming intensity is balanced with the outgoing intensity in every wavelength interval across the spectrum.
I also learned that the earth is an open system far away from thermodynamic equilibrium, but of course in a stationary state or close to it with radiative balance.
9 July 2008 at 1:28 PM
#77 Joseph
Slightly out of balance is subjective and relative.
Maybe the best way to say it is to generalize. We were fairly in balance prior to the industrial revolution. The climate forcing was following the natural cycle and in a slight cooling trend.
Then we added industrial based GHG’s which added forcing to the system. Now the ocean has to absorb the extra forcing to get a new warmer equilibrium. So getting back into equilibrium is not as favorable as it may sound.
I’d rather attain equilibrium at a lower lever than where this is headed. But as Steven Colbert from the Colbert report has mentioned in response to Michael Griffins (NASA Director) statement about “who is to say the climate we have is the ideal climate…”, Colbert responding, “who are we to say that pacific islanders prefer their islands above water”
http://www.uscentrist.org/videos/word-items/mission-control
http://www.uscentrist.org/videos/word-items/airogance
We really don’t have a handle on the compounding of positive feedbacks, but there is some paleo precedence for an anomaly in the direction of 8 degrees. There is reason to lean toward the upward scenario, in my opinion, given variables, given BAU, given, what we know, et cetera, et cetera…
Yes we are pushing further away from equilibrium at this point.
9 July 2008 at 1:53 PM
Re Aaron @86: “Despite these fluctuations the atmosphere is able to bounce back and return to the basically the same equilibrium position in a rather short period of time”
That’s because both volcanic ash and sulfuric acid aerosols don’t stay in the atmosphere very long, hence the forcing does not last very long.
9 July 2008 at 2:37 PM
Paul (70) — Your question probably more properly ought to be asked on
http://climateprogress.org/
which is run by energy expert Joe Romm.
9 July 2008 at 4:31 PM
re #81 Chuck,
Your nits are well picked….! In my understanding the carbonic acid-bicarbonate equilibrium does contribute to the maintenance of blood pH (as a very weak buffer 1 pH unit away from its pKa - it buffers somewhat against acidification which takes the pH back towards the pKa). However your depiction of a more “passive” role for the carbonic acid-bicarbonate equilibrium around which the physiology of pH homeostasis and O2 uptake/CO2 excretion evolved, is a beter way of considering the broader picture.
9 July 2008 at 4:39 PM
#94 Jim
The point I was trying to make with volcanoes, especially the big ones, is that when they erupt, they provide a very large, short impulse fluctuation to the earth’s atmosphere. Despite these very large fluctuations (Tambora created temperature differences of up to 20 degrees at some latitudes and even caused famine all the way across the world!) the atmosphere was still able to find an equilibrium that looked similar to that of before the eruption not long there after. I’m really just asking if there is some kind of estimate for how much the earth’s atmosphere can take it terms of a fluctuation. I know it can take large volcanic eruptions. If you integrate over enough time, does CO2 input from people push the atmosphere passed this fluctuation limit? I don’t know, but it seems like a pretty straight forward question from a pure physics standpoint. As far as I know, there is no reason to believe that this is an overly simplified point of view.
#82 Ray
Can you please give me some more information on Schwarz? I would be interested into seeing more of this person’s work.
9 July 2008 at 5:02 PM
Re #84: Mike, you make this statement –
“The dreary summers afflicting Ireland, Britain, France, Scandinavia and Benelux as well as Spain, Portugal and Italy are causing increased scepticism about the reality of global warming.”
– and then ask if anyone has any statistics about these “dreary summers”? A climate shift along the lines of what you describe would be rather big news, I think. You can use the internet to look at the numbers and see if there’s anything to this. It shouldn’t take you long.
Also, increased scepticism on whose part? Do you have some sort of survey data to back up this claim?
Weather/climate and public opinion are two areas where sceptcism should first be applied to seat-of-the-pants personal assessments. Try that, please.
9 July 2008 at 5:28 PM
Aaron, you can read about Schwartz here:
http://www.realclimate.org/index.php/archives/2007/09/climate-insensitivity
Schwartz is not a bad scientist, but this shows what can happen when somebody with an incomplete understanding of the science wades too deep.
I am curious about your contention that you are weighing “both sides” of the argument. Where are you getting the denialist side–because it sure ain’t in the peer-reviewed literature. The profession of publishing significant insights into climate while denying that humans are playing a significant role is absolutely moribund. So where is this “other side” you keep talking about.
9 July 2008 at 5:56 PM
Re #97, Aaron asked whether there is “some kind of estimate for how much the earth’s atmosphere can take in terms of a fluctuation.”
Aaron, I infer you think the atmosphere has some sort of general-purpose equilibrator. It does not have mechanisms that per se strive for equilibrium of all the Earth’s characteristics. (The Gaia metaphor must not be taken too literally.)
It does have some specific mechanisms that counteract some specific changes. But those mechanisms do not pay attention to whether they are exacerbating other changes.
Jim’s example (#94) was that volcanic ash and sulfuric acid aerosols cool the Earth by reflecting incoming solar radiation. Those substances quickly precipitate out, thereby counteracting the specific effect of cooling from those specific substances.
But suppose the Earth was already cooling, and so much so that it was heading into an ice age. The precipitation of the volcanic sputum then would exacerbate the global, net cooling trend from all influences.
So that precipitation is not inherently a global equilibrator. It just does its own thing, sometimes with the global effect of counteracting net global trends (equilibrating), and sometimes amplifying those trends (disequilibrating).
So the answer to your question of whether there is “some kind of estimate for how much the earth’s atmosphere can take in terms of a fluctuation” [my emphasis on “a”], is that there is no single answer, because the answer differs depending on the specific causes, directions, and sizes of the fluctuations.
Back on point of Jim’s reply: Fluctuations due to volcanic eruptions peter out quicker than fluctuations due to, say, chronically increasing CO2 levels in the atmosphere.