Catastrophic man-made global warming advocates have claimed that while this may have been the case in the past, since 1975 the warming has been caused by, and therefore preceded by, increases in atmospheric CO2 due to man's use of fossil fuels. However, actual evidence that the general temperature increase since 1975 was actually caused by increases in atmospheric CO2 was severely wanting.
So has the recent increase in atmospheric CO2 preceded or followed the recent increase in temperature? A relatively recent paper by Humlum, Stordahl, and Solheim entitled The phase relation between atmospheric carbon dioxide and global temperature published in Global and Planetary Change, Vol. 100, January 2013, p. 51-69 answers this question.
They found that since 1982, atmospheric CO2 concentration changes lagged:
- global sea surface temperature changes by 11 to 12 months.
- global surface air temperature changes by 9.5 to 10 months.
- global lower troposphere temperature changes by 9 months.
If atmospheric CO2 increases lag temperature increases both in the recent warming since 1982 and warming periods over the last 400,000 years, then increased CO2 in the atmosphere is caused by the warming. There is no case for the hypothesis that increased atmospheric CO2 is the cause of warming.
Adding this observation to the failure of temperatures to increase over the last 13 years even as atmospheric CO2 concentrations have increased must be very disturbing to the climate alarmists. The settled science of catastrophic man-made global warming due to CO2 emissions is becoming so unsettled that we have to conclude that the hypothesis has failed. That it has failed comes as no surprise given the basic physics of the climate which I have recently explained here.
There is no case based on climate catastrophe for forcing man to stop using reliable and inexpensive fossil fuels in favor of unreliable and very expensive energy sources such as biomass, wind generation, and solar photovoltaic or concentration plants. This is no excuse here for destroying the coal industry and killing coal-fired power plants, discouraging oil pipelines and drilling for oil and natural gas, and condemning commercial and residential consumers to spending much more on energy that is much less reliable.
Posts
22 comments:
It's not like we wait for the temperature to go up before we emit CO2. Obviously CO2 does not lag temperature when human beings are emitting it straight into the atmosphere, regardless of the temperature.
From the viewpoint that the emissions of man are greater than changes in natural emissions, your comment appears well-founded. But it is that very assumption that the CO2 emissions of man are greater than natural emission of CO2 variations that these observations are bringing into question.
I am not assuming man's emissions are greater than nature's. They aren't.
But nature takes up carbon as well as emits it. In fact, nature is taking up more carbon than it emits, which is why only about half of man's emissions stay in the atmosphere annually. It is man's emissions that are causing the atmosphere's CO2 concentration to increase, and that has nothing to do with temperature or a temperature lag.
Man's emissions are such a small fraction of natural emissions that it is not proven that man's emissions are causing the increase in atmospheric CO2 concentrations. However, since the increase in CO2 concentrations in the atmosphere is a good thing, if man is causing the increase, man is doing well to do so.
The CO2 concentration in the atmosphere was essentially constant for many millennia before the industrial era. Only then did it start increasing exponentially.
Isotopic analysis of atmospheric CO2 shows that the increase is from burning fossil fuels, not from natural CO2 sources:
http://www.realclimate.org/index.php/archives/2004/12/how-do-we-know-that-recent-cosub2sub-increases-are-due-to-human-activities-updated/
Besides, where do you think all the CO2 man generates by burning fossil fuels goes anyway -- tens of billions of tons a year of it?
Despite the warming of the oceans since the end of the Little Ice Age or since about 1850, the catastrophic man-made global warming view is that the increase of CO2 in the atmosphere is almost entirely due to the Industrial Age use of fossil fuels and wood. The evolution of CO2 from the warming oceans due to its decreased solubility at higher temperatures is dismissed as just too inconvenient for their hypothesis. C13 is preferentially retained by the oceans as they allow the dissolution of more of the lighter C12. So increased concentrations of C12 of the atmosphere need not come only from man's use of fossil fuels. What is more, many of the natural sources of CO2, such as geothermal sources, are not well-characterized as to either the amount of CO2 emissions or the isotopic ratio. That the amounts are large and highly variable is readily seen in the AIRS satellite images I discussed in this post: http://objectivistindividualist.blogspot.com/2015/08/you-would-not-believe-how-busy-santas.html
The advocates of the government-mandated catastrophic man-made global warming hypothesis have a long history of cherry-picking tree ring and ice core data to make their case for man being responsible for the increase in CO2 in the atmosphere. Of course, natural sources have raised the level of CO2 in the atmosphere many times above present levels in the past. Some diffusion of CO2 dissolved in ice does occur, so we do not know how many 200 year or less increases in CO2 atmospheric concentrations are simply lost in the resulting decrease of time resolution in the ice cores. But we do know from the very ice core data that you are trying to use to make your point that actual temperature increases follow 800 or more years after CO2 increases in the atmosphere have occurred. Nonetheless, the anti-fossil fuel people claim that in the present case, an increase in CO2 concentrations in the atmosphere has caused immediate temperature increases.
Carbon isotopic dating has recently been shown to have many more problems with reliability than had been thought. In general, changes in isotopic ratios of 0.15% are subject to much more uncertainty than your reference claims such changes to have.
Finally, I am most certainly not making the claim that man's use of fossil fuels has not added to the concentration of CO2 in the atmosphere. It must do so. I am claiming that the claim that man's use of fossil fuels has caused almost all of the increase of CO2 in the atmosphere since 1850 is exaggerated. I would also repeat that plants are very grateful to us for whatever contribution we have made to the increase in CO2 in the atmosphere. What makes plants happy makes many animals happy, including humans who are better able to feed the growing population of humans on Earth. To be sure, the increase in CO2 does cause a small cooling, which is not as desirable as a small warming would be, but the benefits to our plants far outweigh the cost of the small cooling effect.
"The evolution of CO2 from the warming oceans due to its decreased solubility at higher temperatures is dismissed as just too inconvenient for their hypothesis."
It's not inconvenient, it's wrong -- the ocean is also gaining CO2, acidifying.
The atmosphere, ocean, soil and vegetation are all taking up more carbon than before. Because we're digging up carbon that was sequestered tens of millions of years ago and burning it.
"I would also repeat that plants are very grateful to us for whatever contribution we have made to the increase in CO2 in the atmosphere. What makes plants happy makes many animals happy, including humans who are better able to feed the growing population of humans on Earth."
This also isn't true. Food quality is already declining, and will decline more with higher CO2 and higher temperatures:
“Total protein and nitrogen concentrations in plants generally decline under elevated CO2 atmospheres…. Recently, several meta-analyses have indicated that CO2 inhibition of nitrate assimilation is the explanation most consistent with observations. Here, we present the first direct field test of this explanation….. In leaf tissue, the ratio of nitrate to total nitrogen concentration and the stable isotope ratios of organic nitrogen and free nitrate showed that nitrate assimilation was slower under elevated than ambient CO2. These findings imply that food quality will suffer under the CO2 levels anticipated during this century unless more sophisticated approaches to nitrogen fertilization are employed.”
-- “Nitrate assimilation is inhibited by elevated CO2 in field-grown wheat,” Arnold J. Bloom et al, Nature Climate Change, April 6 2014.
http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2183.html
“For wheat, maize and barley, there is a clearly negative response of global yields to increased temperatures. Based on these sensitivities and observed climate trends, we estimate that warming since 1981 has resulted in annual combined losses of these three crops representing roughly 40 Mt or $5 billion per year, as of 2002.”
-- “Global scale climate–crop yield relationships and the impacts of recent warming," David B Lobell and Christopher B Field 2007 Environ. Res. Lett. 2 014002 doi:10.1088/1748-9326/2/1/014002
http://iopscience.iop.org/1748-9326/2/1/014002
"We also find that the overall effect of warming on yields is negative, even after accounting for the benefits of reduced exposure to freezing temperatures."
-- "Effect of warming temperatures on US wheat yields," Jesse Tack et al, PNAS 4/20/15
http://www.pnas.org/content/early/2015/05/06/1415181112
The solubility of CO2 in water near 15C is changes at a rate of about -0.0825 g/kg K, so a 1.2 K increase in temperature since 1850 would cause a loss of CO2 in water of about 0.071 g/kg of water. At 15C, the amount of CO2 in water at present partial pressures is about 1.95 g/kg, so a 1.2K increase in temperature leads to about a 3.6% loss of dissolved CO2 in water.
However, the solubility increases linearly with the partial pressure of CO2, so a change in partial pressure from 280 ppm to 400 ppm results in an increase of dissolved CO2 of about 43%. So, the claimed warming of the oceans does not produce nearly enough CO2 loss to compensate for the much larger increase in the solubility due to the partial pressure increase in CO2. Consequently, the oceans are expected to experience a small decrease in alkalinity, since about 0.0017 of the dissolved CO2 becomes carbonic acid, a weak acid.
So, the warming of the oceans is insufficient to account for the increase in atmospheric CO2 concentration. There is no doubt that some fraction of the remainder is due to man's use of fossil fuels and the combustion of wood and peat. The AIRS data I referred to in my last comment makes it clear that most of the CO2 entering the atmosphere is not coming from heavily populated and industrialized areas, however. Among areas implicated by the AIRS data are geothermally active areas in the oceans.
I will repeat that since increases in atmospheric CO2 do more good than harm, to the degree that man is responsible for the increased concentration of CO2 in the air, he is to be congratulated for it. Those congratulations would be even stronger is CO2 actually did warm the surface. As it is, I am happy to accept the slight cooling of the surface for the tremendous advantages to growing plants and to assisting plants in producing more oxygen.
Charles wrote:
"However, the solubility increases linearly with the partial pressure of CO2, so a change in partial pressure from 280 ppm to 400 ppm results in an increase of dissolved CO2 of about 43%."
But up above you wrote that the ocean was emitting CO2: ""The evolution of CO2 from the warming oceans due to its decreased solubility at higher temperatures is dismissed as just too inconvenient for their hypothesis.""
So which is it?
You didn't take into account the temperature dependence of the Henry's Law constant.
Ocean acidification already exceeds your calculation -- between 1751 and 1994 surface ocean pH is estimated to have decreased from approximately 8.25 to 8.14.
Jacobson, M. Z. (2005). "Studying ocean acidification with conservative, stable numerical schemes for nonequilibrium air-ocean exchange and ocean equilibrium chemistry". Journal of Geophysical Research – Atmospheres 110: D07302.
http://onlinelibrary.wiley.com/doi/10.1029/2004JD005220/abstract
Charles wrote:
"I will repeat that since increases in atmospheric CO2 do more good than harm...."
I notice you censored my comment with evidence increased CO2 leads to decreased food quality, and the warming it creates leads to lower yields on crops like wheat.
If you're going to censor comments, I'm not interested in continuing this discussion.
Why is it the deniers are always the ones who censor science?
This does more to harm your reputation than anything else.
You claim you are a scientist. Why then aren't you committed to a free and open exchange of ideas? What are you afraid of?
I own and operate a materials analysis laboratory and I have been very busy with projects of late. I try to scan my 375 e-mails a day to pick out the important ones to respond to, but when I am flat out working, by scans are subject to missing things. There was no censoring going on in the case of the above David Appell comments. They were just missed.
Clearly my comment to take into account the partial pressure increase of CO2 on the solubility of CO2 in water was to supplant the earlier argument in which I did not take that into account. There is no temperature dependence on the effect of the partial pressure by Henry's Law in the temperature range from 0 to 25C. See http://sites.chem.colostate.edu/diverdi/all_courses/CRC%20reference%20data/solubility%20of%20carbon%20dioxide%20in%20water.pdf
David: "I notice you censored my comment with evidence increased CO2 leads to decreased food quality, and the warming it creates leads to lower yields on crops like wheat."
Are you talking about your comment of 29 November above or is there one which is slightly different that I might have missed?
It is interesting that the claim of lowered crop yields has come when most crop yields have been increasing throughout the last 30 years. Corn yield has climbed steadily since 1936, see http://www.ers.usda.gov/topics/crops/corn/background.aspx Wheat yields have increased slightly from 1980 to 2012, see http://www.ers.usda.gov/media/1182545/eib116.pdf Soybean yield is also up slightly from 1975, see http://www.ers.usda.gov/topics/crops/soybeans-oil-crops/background.aspx These time periods cover those in which CO2 has been increasing and temperature increases have been claimed by the mercenary scientists bought by government grant money.
Of course, should temperatures change the optimal locations for growing various crops will shift slightly. Less wheat would be planted in southern Kansas and more in North Dakota if any warming actually did occur. However, added CO2 does not cause warming so one cannot attribute such shifts to changes in the CO2 concentration in the atmosphere.
"It is interesting that the claim of lowered crop yields has come when most crop yields have been increasing throughout the last 30 years."
You are not a very good scientist.
Obviously, crop yields depend on more than one variable. Is that so difficult to understand?
Studies find that AGW is decreasing yields. That hardly means total yield is decreasing. Didn't you ever learn about multivariable analysis?
"However, added CO2 does not cause warming so one cannot attribute such shifts to changes in the CO2 concentration in the atmosphere."
So do you think CO2 doesn't absorb infrared radiation, or do you think the Earth doesn't emit any?
Crop yields certainly do depend on more than one factor. Increased CO2 in the atmosphere provides plants with more food, CO2 being essential to their growth. There are many studies that verify better growth of many plants due to higher concentrations of CO2. At this time it is entirely unclear what the effect of additional CO2 in the atmosphere is on other factors such as temperature and water moisture and rainfall which affect plant growth. Consequently, these other effects on plant growth do not have a known dependence upon CO2 atmospheric concentrations, though some papers assume such knowledge.
CO2 both absorbs and emits infrared radiation. It absorbs some incoming solar insolation well up in the atmosphere, preventing that radiation from reaching the surface and warming it. It soaks up heat from nearby nitrogen and oxygen molecules and emits some of it as infrared radiation to cooler layers of atmosphere above the layer it is in. Since this energy emitted as radiation travels to a cooler and higher layer before being absorbed, this effect transports energy upward more quickly than convection does. This is a cooling effect. CO2 at still higher altitudes such as the upper troposphere, the tropopause, and the stratosphere emits radiation straight out to space, which is most certainly a cooling effect. The absorption of radiation from the surface slows the cooling of the surface by radiation and is a warming effect. This is a rapidly saturating effect as atmospheric CO2 concentrations increase. All of the other effects are cooling effects and most of them do not saturate so rapidly. Upon increasing CO2 from zero concentration initially the net CO2 effect is a warming effect. Further increases will cause the effect to transition from a less and less warming effect to a more and more cooling effect.
No, it's not "entirely unclear" what the effect of factors other than CO2 is on plants.
“For wheat, maize and barley, there is a clearly negative response of global yields to increased temperatures. Based on these sensitivities and observed climate trends, we estimate that warming since 1981 has resulted in annual combined losses of these three crops representing roughly 40 Mt or $5 billion per year, as of 2002.”
-- “Global scale climate–crop yield relationships and the impacts of recent warming," David B Lobell and Christopher B Field 2007 Environ. Res. Lett. 2 014002 doi:10.1088/1748-9326/2/1/014002
http://iopscience.iop.org/1748-9326/2/1/014002
“Higher CO2 tends to inhibit the ability of plants to make protein… And this explains why food quality seems to have been declining and will continue to decline as CO2 rises — because of this inhibition of nitrate conversion into protein…. “It’s going to be fairly universal that we’ll be struggling with trying to sustain food quality and it’s not just protein… it’s also micronutrients such as zinc and iron that suffer as well as protein.”
- University of California at Davis Professor Arnold J. Bloom, on Yale Climate Connections 10/7/14
http://www.yaleclimateconnections.org/2014/10/crop-nutrition/2014
"We also find that the overall effect of warming on yields is negative, even after accounting for the benefits of reduced exposure to freezing temperatures."
-- "Effect of warming temperatures on US wheat yields," Jesse Tack et al, PNAS 4/20/15
http://www.pnas.org/content/early/2015/05/06/1415181112
"Negative impacts of global warming on agriculture, health & environment far outweigh any supposed positives." Smith et al. PNAS (2009), http://www.pnas.org/content/106/11/4133.full.pdf
"Does a Warmer World Mean a Greener World? Not Likely!," Jonathan Chase, PLOS Biology, June 10, 2015.
http://journals.plos.org/plosbiology/article?id=info:doi/10.1371/journal.pbio.1002166
There are many more.
If CO2 was so good for plants, Venus, where the atmosphere is 96% CO2, would have them in great abundance.
Of course CO2 both absorbs and emits IR. But its net effect is warming (part of the greenhouse effect) and, now, more warming (the enhanced greenhouse effect).
CO2 absorbs very little incoming solar irradiation, because solar radiation contains little IR.
CO2 does not "soak up heat from nearby nitrogen and oxygen molecules" because those molecules don't emit in the IR. (If they did they'd also be GHGs!)
"CO2 at still higher altitudes such as the upper troposphere, the tropopause, and the stratosphere emits radiation straight out to space, which is most certainly a cooling effect."
Yes -- after its warming effect.
"This is a rapidly saturating effect as atmospheric CO2 concentrations increase."
False, as this graph shows: https://www.giss.nasa.gov/research/briefs/schmidt_05/curve_s.gif
If CO2 were saturated, there'd be no IR escaping to space at the CO2 absorption frequencies. (You claim is also inconsistent with your claim above that some CO2 emissions escape to space.)
"Upon increasing CO2 from zero concentration initially the net CO2 effect is a warming effect. Further increases will cause the effect to transition from a less and less warming effect to a more and more cooling effect."
There is no science to support this claim, and you haven't provided any. It's false. (See: Venus.)
I am sure there is much to learn yet about the nutrition effects on some grains as a function of the CO2 concentration in the atmosphere. At this point, the religious mania to justify the catastrophic man-made global warming alarmism is so great that it is very difficult to be confident in all the published papers. Some of the papers you pointed at seem to say that warming may decrease US production of some crops. Perhaps that just means that Canadian production of those same crops might increase.
The net effect of CO2 is warming at very low concentrations. As the concentrations increase, the additional warming becomes less and less and then finally becomes a cooling effect. This is known to be the case with water vapor, though water vapor has even more cooling mechanisms than does CO2.
CO2 most certainly does soak up heat from the collisions with nitrogen and oxygen molecules that cause it to equilibrate in temperature with them. Then as convection currents rise, it carries more heat upward per molecule because it has a higher heat capacity than do nitrogen and oxygen molecules. This is a cooling mechanism.
CO2 cannot possibly prevent all of the radiation at the wavelengths that CO2 absorbs from escaping into space for the simple reason that it will never be a black body absorber at 0K even over its limited wavelength range of absorption. More importantly, the mean free path for absorption of CO2 emitted thermal radiation is very short in the lower to mid troposphere, so the differential temperature between emitter and absorber is small. This means that the fraction of surface emitted energy absorbed by CO2 is very small, as is that from each layer of air within the lower and mid troposphere.
Venus has a much denser atmosphere than does the Earth and the final weighted altitude for emission of radiation to space is high, so it is hot. What is more, the relation of CO2 to N2 and O2 is very different on Venus.
Physicists are great, yet if 97% of the people were physicists, society might not function very well. Plants need things in addition to CO2, such as temperatures below the average Venus surface temperature of 750K. You do realize that water boils at a much lower temperature than 750K, do you not? So now you understand why plants do not thrive on Venus.
Post a Comment