An Icy Chill
Poznan has been – from the warmist perspective – a failure. Put in an over-simplified nutshell – the more developed countries are reluctant in times of grave economic uncertainty to bring in measures which would cripple their economies and the less developed countries are damned if they are going to stay perpetually less developed by failing to adopt the technologies they need.
This failure comes a no surprise to people who look at the economics of carbon reduction and it comes as a relief to those of us who are more than a little doubtful about the effectiveness of such a strategy.
The warmist argument comes down to the assertion that a) manmade CO2 acts as a significant greenhouse gas, b) that as the result of its emission the world is getting warmer, c) that there are no other plausible explanations for “global warming” and, d) that it makes economic sense to reduce CO2 emissions.
The policy conclusion, d), implies a huge economic effort, the loss of millions of jobs, the transfer of billions of dollars from rich economies to poor ones and the assertion that “global warming” is a threat of sufficient magnitude to justify such action. To maintain that argument, at a minimum, the science underlying a,b, c above has to be right.
Is it?
b) requires some proof that the Earth is, in fact, getting warmer. And that, in its turn, implies some sort of scale. Warmer than what? For example, it is pretty clear that in the last decade the Earth has been getting cooler. And, despite the efforts of the warmists to statistically eliminate it, it seems clear that the medieval warm period was warmer than even 1998 and the warm years of the 1930’s.
Worse, there is a growing body of evidence that the modern instrumental temperature record (which shows warming in at least the Northern hemisphere) may be significantly flawed and biased towards warming. The Urban Heat Island effect is significant enough that the temperature record has had to be adjusted. But those adjustments, in themselves are open to question. As well, as Anthony Watts has so damningly demonstrated, at least in the United States surface station placement has resulted in literally hundreds of stations place in sub-ideal locations for measuring temperature. (Not too bright to stick them in the middle of asphalt parking lots, atop tarred roofs or beside the exhaust of air conditioning units.)
The fallback of the warmists is the past, non-instrumental, record. Tree rings, sediments, ice cores – all of which may be proxies for temperature and some of which may suggest that there has been an increase in temperature in the last 150 or so years. The problems with these proxies and their statistical treatment are detailed at Climate Audit. However, the biggest problem is that none of the proxies are obviously about temperature. To give a simple case: tree ring data reflects growth and growth is effected by all manner of variables – moisture, temperature, snow cover, cloud and nutrient environment being just a few. So, long before one has to deal with the statistical novelties the paleo-climate folk inflict on their data, the issue of what that data actually reflects has to be addressed.
However, assume for the moment that, somehow, despite current evidence, the warmists manage to convince you that the world is getting warmer. Is CO2 the culprit and, if it is, is manmade, CO2 to blame. This is the essential question in “a” above.
It is rather obvious that CO2 is a trace gas which is critically important to life on Earth – no CO2, no green plants – and is non-toxic to humans and other animals. A great deal of the CO2 in the atmosphere comes from natural sources, volcano, breathing, vegetation rotting and the oceans evaporating. It has varied wildly in concentration ranging from nearly 100% of the Early Earth atmosphere to around 280 parts per million at the end of the 18th century to 370 parts per million today. The argument is that the difference between the 1800 concentration and the current concentration is due to human activity. (There is no scientific proof for this assertion, just the reasonable claim that we have been burning fossil fuels prodigiously and therefor are likely responsible.)
The interesting thing about CO2 in general, and manmade CO2 specifically, is that there is no clear link between concentrations of CO2 and temperature. There are models which suggest that as CO2 rises so does temperature; but these models run into a plethora of confounding variables – water vapor (which may well account for 95% of all global warming), methane and a host of other “greenhouse” gases all contribute to any model which postulates warming. The precise contribution of CO2 - much less manmade CO2 - depends on the assumptions going to these other gases. Worse, a lot of the most basic science on CO2 is in its infancy. For example, we have only an approximation as to how long CO2 lasts in the atmosphere – the estimates range from a few years to a century.
The models also suffer from the issues which confront all computer models: they can only use past events to forecast current and future events and they are extremely difficult to calibrate to the real world. A good computer model should be able to predict the past nearly perfectly. That is, running the model against the known past should give a nearly perfect fit. (A task made more complicated when the “known past” is known imperfectly or through proxies which, themselves, may be open to question.) If a model is able to match the past then it makes sense to test it against the future.
Current climate models are being tested against the future and they are failing. The climate models favoured by the IPCC and the climate science community all suggested that as CO2 concentration rose so would temperature. However, for the last decade, CO2 levels have risen but temperature has either plateaued or dropped depending on where you place the starting point. The predictive “skill” of the models seems to be declining as more real world data is fed into them.
Part of the reason for this is that in the nature of models they must be simplifications. A one to one model of the Earth’s climate is simply too large and too complex to be run. So climate models integrate various assumptions some of which may be only partly right. Another reason the models fail is that complex relationships are certainly not linear but their actual description may be very complicated indeed. Models work best with linear relationships or relatively simple non-linear relationships.
The failure of the current crop of models tells us one of two things or maybe a little of both: temperature does not move in lockstep with CO2 concentrations and there maybe other, confounding, variables which account for changes in temperature.
Which brings me to c). The failure of the models to predict the current cooling suggests that there may be things other than CO2 (man made or natural) which have an impact on temperature. Here are a few candidates – the sun’s output, cyclical fluctuations in the oceans, relative concentrations of greenhouse gases, relative levels of snow cover, the colour of snow – and there are many more.
To make the argument for the radical reduction of man made CO2 with its attendant economic and human costs, we need to be certain that such a reduction is actually going to address the issue of climate change. And such certainty collapses in the face of alternative explanations even where those alternatives account for a relatively small fraction of the predicted or observed change.
The reason for this collapse is that the contribution of man made CO2 to global warming is .117% of the greenhouse effect and if, for example, 20% of that effect can be attributed to solar variation, the effect of CO2 would drop beneath the 1/10 of 1 percent level. Most of the trivialization of CO2 arises when we actually pay attention to water vapor, the rest when we note the effect
Confronted with the rather rickety nature of their claims warmists tend to retreat to versions of the “precautionary principle” – what if doing or not doing “x” now leads to terrible consequences later? Shouldn’t we stop doing/start doing stuff to reduce those consequences?
Of course, that is a sword which cuts both ways. Cutting CO2 emissions has real costs right now. And those costs have real consequences both in the developed world and in the less developed world. If we proceed on the basis of uncertain science, unsophisticated models and the arrogant belief that we actually understand the complex system which is climate, we are making an extremely risky choice. Real people will experience real harm more or less immediately as they lose their jobs, their mobility, their capacity to develop and their hope for a brighter future.
The difference is that the losses created by radical CO2 emissions reductions are very real and very quantifiable. The gains created by such reductions are entirely speculative and cannot be quantified.
Certain harm versus potential harm averted. This should not be a difficult policy decision.
December 15th, 2008 at 5:43 am
Jay…a very logical, well-presented piece. I’m impressed! Out of curiosity, what is your educational background? From reading your blog, I would have guessed a background in economics, but now I’m wondering if it is science. In any event, you’re a smart cookie and I always appreciate your analysis on your blog and on The New Al and Mike (and Jay!!) Show. Cheers!
December 15th, 2008 at 7:19 am
Good summary. You should submit it to the Times Colonist or one of the other dead tree papers which “destroy” the environment every day to tell us in what bad shape the environment is in.
December 15th, 2008 at 9:49 am
Thanks David,
I have a varied background. Philosophy, Political Science, Law with a huge concentration on policy studies and economics. But I have been reading science since I was about ten and have enough math that I can follow, if not make, a statistical or econometric argument.
December 15th, 2008 at 9:50 am
Hi Jay: I like your presentation especially because it provides some clear statements which we can use as the basis for an analysis.
You mention your points a, b, c as being questionable and begin with point b. That serve as a good place as any to start, so……. I would not agree that in fact the Earth is getting cooler. The data set that we use is pretty noisy so lets look at the stats involved (and I would encourage you or anyone to check my stats – I used Excel). The data set that I like to use is the GISS land ocean. If you plot the data using 1996 as a starting point you get a trend of about 0.15 C/decade. If you start in 1998 you get 0.09 C/decade and if you start in 1999 you get 0.17C/decade. So there is no indication of a cooling trend in that data.
If you wish, you can use the satellite measurements (which avoid a lot of problems – and introduce some of their own as S&C will tell you). Using the RSS dataset if you plot the data from 1998 onward you do get a slight cooling rate of –0.06C. However if you plot it from 1997 you get a warming rate of 0.03 and if you plot it from 1999 you get 0.10. So to summarize, if you pick one year you can get a cooling rate, but if you take either more or less data then you get a warming rate. That sounds like cherry picking to me.
In regards to the location of the climate stations, keep in mind that a lot of those were sited before modifications were made to the site, so there was no intentional poor siteing as you seem to suggest. However the important thing is what effect does the site have. If you review the ClimateAudit archives on this topic you will see a series of posts by someone named John V. What John V did was to separate out the best sites (those graded 1 or 2) and then compare the results to the worst sites (3, 4 and 5). His work showed that there was very little difference between the results – indicating that the poor siteing did not affect the results significantly.
However, keep in mind that there are other things that tell us the world is warming. Arctic ice extent in summer, glacial extent, sea-level rise, a number of phenology related changes and several others all say that the globe is warming. So I think that we can say that the world is warming.
One note, I am going to ask you to provide a reference that the MWP was warmer than current temperatures. That is the first I heard of it and it seems surprising.
You then go on to look at point a. You appear to not really wish to argue that we are responsible for the current rise in CO2, but you are not correct when you say there is no scientific proof for that assertion. I can think of two different ways to show it. The first deals with the amount of CO2 produced and the amount that shows up in the atmosphere and is a simple logical argument. The second is a more scientific one and looks at the isotope ratios in the atmosphere (fossil fuel C is very depleted in C14).
In regards to the linkage between CO2 and warming, there is a fundamental linkage that shows that CO2 must cause warming (I can go into it here if you wish, but I am sure you have seen my comments on other sites) – however no one ever said that it was the only cause of warming. Thus the climate responds to CO2 as well as to other short term phenomena. Essentially climate is a 30 year phenomena, so that is the time scale that we are looking at.
In regards to knowing everything about CO2, I agree that there are limits to what we know, however you have to get pretty specific to start finding the gaps. For example, a lot of work has been done on residence time of CO2 and it seems to indicate a residency time longer than the time you quote. Keep in mind a great deal of the fundamental research on CO2 came out of the military when they were looking at heat seeker missiles in the 1950’s.
In regards to the models not being correct because they did not predict the “current cooling”. Well, I have already shown that there is no cooling over the longterm trend. However some general comments about the models can be found here! Of course I do some joint posts with John Cook so I may be prejudiced.
Which brings us to point c. I see that you use Monte Hieb’s page which is good because I have already looked at his page. I am a little short on time right now, but tonight I will devote another post to showing what is wrong with his work.
Regards,
John
December 15th, 2008 at 4:45 pm
John, thank you for responding at length. I am going to respond to your points as they come up in your piece and cite snippets for reference. People interested in following the conversation are urged to read John’s full remarks.
I would not agree that in fact the Earth is getting cooler. The data set that we use is pretty noisy so lets look at the stats involved (and I would encourage you or anyone to check my stats – I used Excel). The data set that I like to use is the GISS land ocean. If you plot the data using 1996 as a starting point you get a trend of about 0.15 C/decade. If you start in 1998 you get 0.09 C/decade and if you start in 1999 you get 0.17C/decade. So there is no indication of a cooling trend in that data.
If you look to trends I think it is fair to say that after a run up to the Super El Nino year of 1998 there has been a falling off of the temperature anomaly. I would argue that this amounts to a slight cooling in the last decade; but propose that I am wrong, the best that can be said from the warmist perspective is that there has been a very slight warming since ‘98.
Now a decade long plateau is not unheard of in temperature data. However, given that CO2 emissions and concentrations continued to rise during this decade the absence of significant warming is suggestive.
If you review the ClimateAudit archives on this topic you will see a series of posts by someone named John V…. His work showed that there was very little difference between the results – indicating that the poor siteing did not affect the results significantly.
I am familiar with John V’s work. I don’t take quite what you take from it, however. What I see in his work, as well as the work of surfacestations.com, is the outline of an error term which is, in fact, significant. And it especially significant when you are trying to claim rises in temp on the order of a few hundredths of a degree per decade. It does not take much of an error to render such a claim meaningless.
However, keep in mind that there are other things that tell us the world is warming. Arctic ice extent in summer, glacial extent, sea-level rise, a number of phenology related changes and several others all say that the globe is warming. So I think that we can say that the world is warming.
I will not get into the details of the “other things” save to say that each one you cite is contested. And, rather more to the point, I am not claiming there has been no warming; my claim is that such warming as there has been is difficult, if not impossible to ascribe to man-made increases in CO2 concentrations.
The AGW strong claim, and the only basis for policy change, requires that warming be tied to human CO2 emissions. Warming in itself is not enough.
provide a reference that the MWP was warmer than current temperatures.
I will have to root around for this.
You then go on to look at point a. You appear to not really wish to argue that we are responsible for the current rise in CO2, but you are not correct when you say there is no scientific proof for that assertion. I can think of two different ways to show it. The first deals with the amount of CO2 produced and the amount that shows up in the atmosphere and is a simple logical argument. The second is a more scientific one and looks at the isotope ratios in the atmosphere (fossil fuel C is very depleted in C14).
The first argument is not quite so simple as it must, necessarily, make assumptions about the CO2 latency rate and such matters as ocean CO2 recycling and the effect of climate change on natural carbon release. I won’t comment on the second argument until I recheck some information on the composition of atmospheric CO2.
In regards to the linkage between CO2 and warming, there is a fundamental linkage that shows that CO2 must cause warming … – however no one ever said that it was the only cause of warming. Thus the climate responds to CO2 as well as to other short term phenomena.
Well, if CO2 is not the only cause of warming why are we spending so much time worrying about it? And, less cheekily, how much of the relatively negligible warming we have seen in the last 150 years can be ascribed to CO2. Remember that we are proposing to spend tens of trillions of dollars and to restructure entire economies to combat CO2 emissions – so it is not unreasonable to ask what percentage of observable GW CO2 is actually responsible for.
I’ll leave it there for the moment and look forward to your second installment. The entire question of modeling is big enough to really take a long comment on its own.
December 15th, 2008 at 4:47 pm
Superb post, Jay.
Why don’t you cut it down to op-ed size and
send it off to a paper?
You’d have a hook with
the recent conference and Prentice’s comments.
December 15th, 2008 at 11:09 pm
Hi Jay: Here is part 2. It addresses your statement “the contribution of man made CO2 to global warming is .117% of the greenhouse effect”.
The 0.117% comes from an argument with two basic errors. The first is the statement that water accounts for 95% of the greenhouse effects. The second is for the assertion that the anthropogenic component of the atmosphere is 3.225%.
The reference for the 95% number appears to be a paper by S.M. Freidenreich and V. Ramaswamy that is given in 4a and also is the basis for the reference 4c (the other references don’t amount to much). However the paper does not say what Hieb thinks it does. That paper is talking about the absorption of solar energy and not the longwave radiation the surface emits which is the driver of the greenhouse effect. The key is in the title Solar Radiation Absorption … however I would encourage you to track down the paper and read it.
The 3.225% is derived from the numbers in table 1 where he claims that the anthropogenic CO2 is 11,880 ppb. The reference given for this number is the Carbon Dioxide Information Analysis Center (part of the US DOE). The problem is that the CDIAC does not say that anywhere! In fact, a conservative estimate is that over 30% of atmospheric CO2 is anthropogenic in nature.
So the 0.117 falls apart on both of its fundamental numbers.
Regards,
John
December 15th, 2008 at 11:24 pm
Hi Jay: thanks for the reply. You say If you look to trends I think it is fair to say that after a run up to the Super El Nino year of 1998 there has been a falling off of the temperature anomaly.
Again, looking at the data I don’t see that. Even if we take 1998 as a starting point then we are seeing an increase of 0.09 C/decade since then. I would not consider this slight warming. Also, since climate is generally taken to be an average over 30 years, I could argue that we actually look at the data through a 5 year moving average (or whatever filter you like) in which case the trend is more pronounced.
It is interesting that we are seeing different things in John V’s analysis. I would not have said that there was not that much of an error. While it is common to talk about trends per decade, keep in mind that we are talking about almost 100 years worth of data so a difference as large as you imply would be quite obvious. I don’t remember it being that large. I will take another look at this later on when I have time.
You conclude with ”Well, if CO2 is not the only cause of warming why are we spending so much time worrying about it?”
Because it is one of the ones that we can control and it is acting in only one direction. An El-Nino will cause warming for a while, then cooling. But CO2 will cause a long term trend.
A final question, do you have a reference for the trillions of dollars you mention? I find that financial analysis are not subjected to the same level or review that the science supporting AGW is. I recall about 5 years ago that someone was telling me that if we imposed Kyoto then oil would go up to $60 a bbl and our economy would collapse if prices were kept that high for a year!
Unfortunately I must attend a funeral tomorrow so I will not be able to post until the next day. but I will check in and reply then.
Regards,
John
December 15th, 2008 at 11:32 pm
John, one reason why I find the CO2 argument hard to swallow is that only .03% of the atmosphere is composed of this gas…manmade or otherwise. If man is responsible for 30% of that then we are responsible for .01% or .0001 of the total atmosphere. Which means that we are emitting the one ten thousandth of the atmosphere is reflecting back the long wave radiation you are claiming is responsible for global warming.
Those are busy little molecules!
December 15th, 2008 at 11:42 pm
Even if we take 1998 as a starting point then we are seeing an increase of 0.09 C/decade since then. I would not consider this slight warming.
Whyever not? .09 a decade is a tenth of a degree a century. My panic is contained.
Because it is one of the ones that we can control and it is acting in only one direction.
It is not clear we can control CO2 without imposing huge costs and it is equally unclear that the magnitude of the change potentially caused by CO2 warrants much concern. As I say, a tenth of degree per century is likely manageable.
As to a reference on the trillions: try Richard Nordhaus on Stern and Gore – “Sir Nicholas Stern’s proposed course of action would reduce that damage to $9 trillion, but at a cost of $27 trillion, for a total cost to the world of $36 trillion, $14 trillion more than unmitigated global warming. Al Gore’s package of measures would reduce global warming costs to $10 trillion at a cost of $34 trillion, for a total cost of $44 trillion, twice the total cost of global warming.”
(Just slightly more than bailing out the world’s banks ;)
December 16th, 2008 at 7:04 am
Thanks to Jay and John both. It’s refreshing to see an AGW discussion with such a high light-to-heat ratio.
December 16th, 2008 at 2:47 pm
Hi – the real multibillion dollar question is:
Is carbon emission reduction objectively , definitely worth the cost ?
Left and right wing economists are having cogent , real and compelling debates regarding auto bailouts , yet we should commit billions to AGW on the basis of faith alone? If you want religion , go to church and leave science at the door when you go in (As a practicing christian , I mean this respectfully)
This AGW debate has become a huge bait and switch trick , based on faith and not fact. Let’s go back to the science and stop calling skeptics “deniers” please.
To call a skeptic a denier in real science reveals you as a “cretin” and therefore too “moronic” to understand a thing called the “scientific method”.
December 16th, 2008 at 4:55 pm
Maybe I am behind the times (way behind). I had thought there were some indications that increase in CO2 actually follows temperature increase, rather than temperature following CO2 increase.
Is there a newer reference?
December 16th, 2008 at 4:55 pm
The historical proxy data, though imperfect, shows that CO2 rises AFTER warming, which completely nullifies the AGW theory. That’s all I need to dispel the hoax.
December 16th, 2008 at 5:37 pm
Hi Jay, nice summary with thought-provoking material. I think your four assertions are missing a couple. For example, how about “(c – 1/2) Warming of the global environment and/or increase of CO2 in the atmosphere is an inherently unhealthy/dangerous/cataclysmic prospect for the biosphere and mankind”.
I proffer that there is scant evidence for this assertion. Indeed, both CO2 and moderate warming may each be an incredible boon to the ecosystem, and to the future prospects of our race. At present more people die due to cold each year than to heat. The oceans may rise a few meters. Barring some marvels of engineering, if temperatures rose a couple of degreeswe’d lose a few jewels like Venice and New Orleans, like many old cities (like Alexandria) have been lost over the ages due to shifting sediments and other environmental changes. Perhaps some of the ancient ports that are many kilometers inland today might once again return to their old glory. The end of the world? I don’t think so. Even the most cataclysmic models show literally millennia before the southern polar cap, the ultimate cushion against planetary overheating, going away.
As for CO2, I have great news: it is NOT A POISON. On the contrary, is the elixir of life. It’s not called a greenhouse gas for nothing: Commercial greenhouse operations pump CO2 in to raise the CO2 levels closer to the ideal for plant life—as it was millions of years ago—and are rewarded with far more productive crops than can be attained in open fields in our carbon-starved atmosphere.
Those combustibles we’re burning: not for nothing are they called “fossil fuels”. Every ounce of carbon came from the ecosphere and has been trapped for eons under the earth. Mankind today is returning carbon back into the cycle of life from whence it came, while benefiting from the long-hoarded stores of energy locked up with them in their ancient tombs. It may be that future generations will regard the modern era as the rebirth of earth as a paradise for living things. As we learn how to reduce REAL pollutants and continue to return to the environment its natural endowment of carbon, some of the genuine harm that’s been done to the world by our misguided actions in the past will begin to heal.
Carbon is the necessary building block, and CO2 its most readily available form, for all plant life, which is the base of the pyramid of life, the bedrock of the biosphere. Worried about the boreal forests? The ocean planktons, the subtropical grasslands, the wetlands, the great rainforests of the tropics, stressed by development and exploitation? Give them CO2, their basic nutrient, and let them flourish anew.
Change? Change is good. The environment, the climate, the biosphere, changes … MUST change … else it is dead. The climates of Mercury, Mars, Venus and the moon change very little. That is because they are dead—they do not possess the beating heart of our hale and hearty planet—a climate whose ebbs and flows over the centuries sees, alternately both warm spells and ice ages, small and great. Freeze earth in amber, prevent it from changing from someone’s imagined ideal state ideal, pin it and mount it on your corkboard .. and you kill it by destroying the very plasticity that is paramount to all life and vitality.
December 16th, 2008 at 6:00 pm
I am confused…...........this from The Telegraph,(London), of December 17th :
http://www.telegraph.co.uk/earth/environment/climatechange/3794475/Last-decade-is-the-warmest-on-record-scientists-say.html
Please advise as to whether this damned planet is warming or cooling?
December 16th, 2008 at 6:11 pm
Jay,
.09 degrees per decade comes out to .9 degrees per century… excellent post though, improved by the comments. If I join the ranks of the unemployed in the near future I think I’ll take some of my free time to get into the data and science to the depth that you and Mr. Cross have and see if I can make enough sense out of it to decide who’s kidding themselves, because two intelligent people looking at the same data and saying “I don’t see it that way, I see it the opposite way” just seems absurd to me (as many things do when they descend to the realm of politics).
December 16th, 2008 at 9:01 pm
This is a great discussion! Very instructive.
I’ve been wondering about something, and R. Craigen’s post hinted at this as well: Is there evidence that the aggregate amount of plant matter on the planet rises and falls with CO2 levels? Does the biosphere automatically regulate atmospheric CO2?
If so, do the IPCC models take this into account?
December 16th, 2008 at 10:28 pm
Thanks Jeff.
I don’t know enough about the effect of the decay of plant matter on CO2 levels to give you much of an answer. It would not surprise me if there was some sort of feedback but what sort I can’t say.
December 17th, 2008 at 1:19 am
A rigorous application of the precautionary principle eliminates the use of the precautionary principle as it would be too dangerous to apply. The unforseen or unintended effects make it’s application untenable, hence a circular argument of no worth. I think that the greatest pain from the weather controllers side is the assumption that change is bad, warm is bad, we are at fault and humans are a plague on the earth. Couple that with our inability to actually make a difference to changes in trace atmospheric gases renders the whole discussion moot.
December 17th, 2008 at 5:59 am
k,ksklxz.cxdslksldkdfsladf;l,dlsmkslpd;
OUCH, MY FOREHEAD. I don’t know about global warming, but the temperature in my living room just went up a few degrees…
To whoever claims that CO2 is great, you’re so very wrong. After being exposed to a certain (and not unfeasible, not very high) concentration of CO2, plant growth diminishes. They do grow faster within a certain small window, but that also has consequences related to nutrient uptake and a huge impact on seasonal cycles.
Anyway. It’s morning, I have a root canal in half an hour, and still have to shovel my driveway…
December 17th, 2008 at 6:08 am
k,ksklxz.cxdslksldkdfsladf;l,dlsmkslpd;
OUCH, MY FOREHEAD. I don’t know about global warming, but the temperature in my living room just went up a few degrees…
To whoever claims that CO2 is great, you’re so very wrong. After being exposed to a certain (and not unfeasible, not very high) concentration of CO2, plant growth diminishes. They do grow faster within a certain small window, but that also has consequences related to nutrient uptake and a huge impact on seasonal cycles.
Anyway. It’s morning, I have a root canal in half an hour, and I still have to shovel my driveway… John’s doing a great job so far. But if you want I can pile all of the papers I’ve read about various aspects of earth and ocean systems in my living room and jump up and down in them for you… like alterations in the earth’s fricken wobble due to polar melt. There are also huge problems with focusing on AGW to the exclusion of water scarcity, food security, soil degradation (and hugely substandard soils in places where we’d want to plant things in 20 years if AGW is happening, and even likely if it is not), mercury in the arctic, CFCs (still a problem), nitrogen – the new CO2, irreversible habitat loss, benthic layers lowering causing krill death leading to catastrophic food chain issues, coral bleaching (whatever the cause), lake acidification (also still a problem), lake warming due to industrial issues (particularly pertinent where I live), OH YEA toxic industrial wastes, huge increases in cancers in humans, feminization of fish due to estrogen-mimicking chemicals in the water, um, hmm, that driveway isn’t getting shovelled by itself.
December 17th, 2008 at 6:12 am
(Oops, forgot my granola. Plants also fix certain chemicals and VOCs (take them into their roots and break them down into smaller less toxic molecules) so reductions in ground and forest cover are doubly problematic. CO2 in dead plant matter is about 10% of wet weight, I believe, you can do the math but I have numbers about the 80m2 of plants that I took care of that they fixed maybe half a kg of CO2 a year at most into carbon by weighed dead mass.)
December 17th, 2008 at 6:15 am
Hi Jay: back in touch again. I will address some of your comments and then in another post discuss what some of the other people have said.
The 0.09C/decade is the smallest rate of increase I could find by cherry picking a very warm start point. I think the interesting thing is that if you take an earlier start point or a later start point you get a larger rate of increase. To get that small an increase you MUST take 1998 (and only 1998) as a starting point. My point was that it would appear to be an anomaly (arising from a large el-Nino) and thus it is dangerous (statistically speaking) to use it as a starting point. Since the November number just came out, I though I would look at the data for this year and plotted the monthly anomalies and then did a linear regression. The rise from that is 2.8C/decade (or 25 C rise by 2100). Do I believe that – of course not. The main problem is that I used January as a starting point and January 2008 was an extremely cool month.
What statisticians do is to run multiple regressions over multiple timescales and then see how the results hold up. If you do this, then you will see that in fact there has not been any significant decrease in the rate of temperature rise over the last few years. Note that this analysis is based only on the GISS dataset.
In your comment # 9 above you raise an interesting point. You say John, one reason why I find the CO2 argument hard to swallow is that only .03% of the atmosphere is composed of this gas…manmade or otherwise.
While that is a tempting argument, there are many examples in the world where an effect seems to outweigh what causes it. For example take a 100 kg man and look at the effects of botulinum toxin on him. A dose of about 0.2 micrograms would be fatal. This is about 1/500,000,000,000!
More to the point, the atmosphere (99.97% of it) consists of nitrogen, oxygen and argon all of which are diatomic molecules. Without getting too much into the physics of it, the modes of vibration of a diatomic molecule do not allow the capture of longwave radiation. However a triatomic molecule will capture longwave radiation. Thus greenhouse gases are generally triatomic such as CO2 or H2O. So when doing your calculation, you should look at the anthropogenic contribution only in terms of CO2 and H2O, not the other atmospheric gases.
Thanks to the link by Richard Nordhaus. I had a skim through it and I find it a fairly good document. I have some questions about it – mostly on what they base their figures on (I was not able to find much of what I thought would be standard reference for a section like that). However we can leave that discussion for another time – perhaps under your posts on models.
Regards,
John
December 17th, 2008 at 6:15 am
GAH, to Joe: CO2 rises after warming because plants aren’t doing their jobs as effectively. If agriculture is increasing then you can count on the fact that soil tillage releases huge amounts of fixed carbon back into the atmosphere too.
Hmm. The snow just keeps a fallin’...
December 17th, 2008 at 6:16 am
2sheds – thanks for the comment!
JohnP: You raise some important points in your post. I would disagree with you that the basis of AGW is faith and I hope that I have established that here. I can understand your dislike of the term denier, but please try to understand that it is used to distinguish between a real skeptic and someone who won’t consider what is placed in front of them or change their thoughts when presented with evidence. Skeptics are necessary in terms of science, denialists – not so much.
Joe: I think that you are talking about the transitions from glacial to interglacial periods. If so, then it is fairly obvious that ice ages are linked to Milankovitch cycles so the question becomes, why would orbital mechanics cause such a large change in the earth?
R. Craigen: I would be careful with your statement about CO2. Obviously, CO2 in higher concentrations is fatal to human life. Is it important for plants – the answer to that is a qualified plant. It depends on a number of factors such as whether the plant is of a type C3 or C4 (we can go into this if you are interested). In my opinion, the most positive aspect of enhanced CO2 will be in arid locations. In higher CO2 a plant will be able to capture CO2 more efficiently which means less water loss to transpiration. Unfortunately, CO2 enhanced plant growth turns out to be deficient in nutrients (nitrogen based ones).
Gabriel: Perhaps, but I find that even on fairly simple topics in science and engineering there is always a wide range of opinions. For example when I run an engineering design meeting, the biggest fights we have (fights in a good way mind you) are over design considerations that you would think would have an obvious “correct” solution. The differences come in based on our backgrounds and experiences. That is perhaps part of the human experience.
Jeff: I am not sure I understand your question, when you talk about plant matter do you mean living, dead or both?
As always, links to back up my statements are available on request.
Regards,
John
December 17th, 2008 at 6:47 am
There’s another point that can be added to your list which relates to the amount of CO2 in the atmosphere now compared to before. Ernst-Georg Beck published a paper last year in the E&E journal which made the case that pre-industrial CO2 levels were much higher than is being accepted and that CO2 peaked in the ‘40’s at over 400ppm.
It’s a really interesting read. In it you’ll find some nice gems, like the fact that J. Collander eliminated any published CO2 levels from his report that didn’t agree with his theory, or how they went about ‘smoothing’ the reported ice core CO2 levels.
As to the question of the MWP being warmer than today, well, there’s so much evidence that the earth has been warmer than today many times in the past. For one example you can read about the Viking settlements in Greenland circa 900 CE.
I think there’s one point of your that should really be hammered home and it’s this: If man is responsible for 30% of that then we are responsible for .01% or .0001 of the total atmosphere. Which means that we are emitting the one ten thousandth of the atmosphere is reflecting back the long wave radiation you are claiming is responsible for global warming.
December 17th, 2008 at 9:27 am
“I am not sure I understand your question, when you talk about plant matter do you mean living, dead or both?”
I should have been more clear.
My question comes down to this. Suppose the addition of 100 tons of CO2 from previously sequestered sources (ie, fossil fuels). We now have 100 tons of additional CO2 in the atmosphere. To what extent does the biosphere absorb that CO2, incrementally, into living plant matter? Will the planet have (after some passage of time as may be required, and ignoring other factors) 100 tons of additional plant material? 50 tons? 1 ton? Or is the effect negative, and the incremental CO2 actually causes a reduction in aggregate living plant material.
My supposition is that within some limits (obviously, plants can not survive at 0% CO2, and I assume they can also not survive at 100% CO2) we will see aggregate living plant mass increase with increased CO2. So I suppose it boils down to three core questions:
1) What percentage of atmospheric CO2 will maximize aggregate plant mass planet-wide?
2) To the extent that incremental atmospheric CO2 results in incremental aggregate plant mass (thus “consuming” some proportion of the incremental CO2), do the IPCC models reflect that?
3) Does human plant cultivation matter? Does planting trees for the purpose of carbon sequestration make sense, or is the aggregate plant mass going to be constant as a function of CO2 levels? (IE, is the tree you plant just displacing one that would have occurred naturally somewhere else?)
December 17th, 2008 at 10:02 am
Jeff:
1. A few ppm within where we are now.
2. Yes. Sequestering carbon via plants is a slow process that takes hundreds of years. Don’t forget that the CO2 we’re burning is coming from things that took tens of thousands of years to form – oil, coal, etc. Look at it this way: they were already sequestered, and we sequestered them. We’re releasing it in a heartbeat. We certainly can’t replicate tense of thousands of years worth of geological pressures in the next fifty to make up for it. We’re also releasing CO2 from the soil (via agriculture and tillage). Granted that since the Green Revolution agricultural yields have been much higher, farms still don’t make up for their carbon footprints.
3. Not really. I mean, it makes sense in the sense that boycotts or taxes make sense – a little bit from everybody adds up to a lot. There is no limit on how many trees we have (??) – although there is a limit on arable land. The more the better, because trees stop soil erosion and filter water and do all sorts of lovely things to help.
December 17th, 2008 at 10:02 am
and we sequestered them
should read “and we UNsequestered them”
December 17th, 2008 at 11:53 am
Jeff: thanks for the clarification. Let me add a couple of comments to Renne’s and see if between the two we have answered (to some extent) your question.
Specifically, looking at your 100 tons of CO2, I don’t think we have the ability to say it will cause an increase from current observations since we are removing fixed carbon at a very fast rate (i.e. forest clearing). The increase in CO2 will cause an increase in plant bio-mass but of course plants eventually die and release the CO2 they stored.
As Renne points out sequestration is a long term process. The ocean is the main location of sequestration and it is currently taking in about ½ of the CO2 that we produce. This CO2 ends up dissolved in the ocean and is used by various organisms which then die and sink to the bottom. Over time the ocean bottom deposits get removed on geological time scales to form rocks, oil, etc.
There was an interesting study done a few years ago where they added liquid iron to an area of the South Pacific ocean (iron is the limiting nutrient in the middle of the ocean). This caused a plankton bloom which then died off and sank to the bottom. They were hoping that this could be a way to sequester carbon on a longterm basis. Unfortunately while it worked well the first time, analysis showed that there were other limits including silicone which would be required to be added in much larger concentrations and would make the process unfeasible. I can dig up a reference to the paper if you are interested.
The IPCC does account for changes in the carbon cycle due to increasing CO2. I even recall a paper that looked at the evolution of plankton under high CO2 concentrations on the theory that in higher concentrations of CO2 would produce plankton that were better able to absorb CO2. I don’t think the result bore out the theory but I was a few years ago that I read the paper.
In regards to planting trees, I think that Renne summed it up well and I can;t really add much except to point out that planting trees is a good short term solution and couldn’t hurt, but eventually they die / burn and then release their carbon.
If the above does not help, please let me know and I will see if I provide further clarification / confusion!
Regards,
John
December 17th, 2008 at 12:33 pm
John and Renee, thanks for very complete and interesting answers with respect to plants and CO2. I think we should be planting trees for their own sake and conserving forests as much as we can irrespective of their contribution to temporary carbon sequestration.
More generally, the bio-mass carbon sink is useful and certainly an important element in how the Earth self regulates CO2; however,I suspect that the effect of any increase in CO2 on the overall biomass of the planet will not be terrifically significant when it comes to CO2 reduction. Or, put another way, the cost of a huge increase in biomass, would likely exceed any benefit which might be gained unless one were to price carbon at tremendously high values.
But, by all means, plant a tree.
December 17th, 2008 at 2:06 pm
Agreed, but it bears pointing out again that forests and wetlands do things other than store CO2. They provide habitat for furry things and feathered things and slimy things, they filter toxins from water and air, they stop soil erosion, they help build soil (it takes about 1000 years to make a half-decent topsoil layer) and they are very pretty.
December 17th, 2008 at 2:41 pm
I’m with you Renee!
December 17th, 2008 at 3:30 pm
Thanks for the great info.
The only thing I’d suggest that still hasn’t been addressed is the question of the aggregate amount of living plant matter on the planet.
Migrating carbon from plant to sediment to geological formations isn’t the only way to sequester it. What about just increasing the aggregate amount of living biomass on the planet? Its true that no individual plant represents “permanent” sequestration, if the total amount of biomass is increased by some percentage will have the same effect. Even as the individual plants die off and new plants regrow, the total amount of carbon they contain will remain.
Renee, you said that, in terms of optimizing plant matter the required CO2 levels are within a few ppm of current. Can you point me to some papers on this. I’m interested in digging a little deeper.
December 17th, 2008 at 7:48 pm
Hey Jeff,
Ok, there’s a lot at play here, not least of which was the fact that I was being a bit flippant :)
Er, hmm. As intro, the earth has had 100ppm and it’s had 1000ppm of CO2 at various times. CO2 does have effects on plant growth, of course, because it drives photosynthesis, but it also decreases water uptake – which can mean more drought-resistant plants, but changes in soil moisture can in turn reduce nutrient uptake. And while a majority (but not all) plants that use one kind of metabolism benefit from higher CO2 up to ~900ppm – light availability and warmer temperature is key, they become more efficient at using it – plants that use another kind or metabolism really don’t at all, or and hit a ceiling at around 450-500ppm. Current earth ambient is 380ppm.
So for the layperson who grows begonias in the greenhouse, a bit of extra CO2 is a good thing when the sun is shining and you’ve got the 20-50-20 out. And you can pipe CO2 into a greenhouse filled with wheat and increase your yields – yet with corn, that won’t work, it has the wrong kind of metabolism.
By and large it’s much more complicated than this in an ecosystem anyway… mainly because nature isn’t a greenhouse, and we’re looking at it longitudinally, looking at community effects, and looking across generations. A good intro to the ecosystem effects of increased CO2 on plants is in this paper:
Körner, Christian. Ecological impacts of atmospheric CO2 enrichment on terrestrial ecosystems. 2006. J. Phil Trans (B) Royal Society.
The same guy gave a good scientific meta-analysis as well, if you’re into the numbers and not just the fancy graphs (there are so many studies on CO2 and plants it’s not funny):
Körner, Christian. New Phytologist. 2006. Volume 172, Issue 3, Pages 393-411
The conclusions from the meta-analysis jibe with others I’ve read and am too lazy to look up right now. Basically it’s that while straight CO2 leads to increases in biomass via increased photosynthesis in the lab, it often comes at the cost of leaf quality and prey preferences (ie: they get eaten faster); there are plateau and acclimatization effects as well in some plants. Also, gains in biomass of a population at large due to higher CO2 are often due to only one or two kinds of plant that thrive (typically legumes), rather than the whole population. This has ecosystem repercussions for the plants who don’t (like evergreens) or just respond slower – and even then it’s often a short-term and non-linear (and sometimes, eventually, negative) response for the precocious ones.
There are a few studies of multi-generational evolutionary effects, too, like this one which discovered that as plants are “treated” with CO2 their offspring become more “resistant” to it – ie their growth rates don’t increase as fast as they should. In short, they adapt to the CO2-rich environment quickly and grow slower, so there are no net primary productivity increases. Some studies also find that seed size suffers, others not… Suffice it to say that acclimation to increased CO2 levels after initial increases in productivity is an acknowledge effect.
Some studies predict an increase in biomass due to warming and CO2 availability together, and others don’t (it’s 1 out of 3 in that meta-analysis), but I had trouble finding studies that didn’t assume a warmer climate given the preferences here for the assumption that there won’t be one :)
In short: far more important to plant growth than CO2 is nutrient availability and other environmental factors such as community makeup. And trees in mature forests, and tundra (a huge carbon sink) don’t really benefit from even somewhat increased CO2 concentrations (and they often grow in sub-optimal soil conditions anyway.)
December 17th, 2008 at 7:54 pm
Whoops, forgot the title for that second paper: Plant CO2 responses: an issue of definition, time and resource supply. Got a URL for you too.