In the CO2 bands radiation emitted by the surface that is not intercepted by WV excites CO2 and the absorbed energy is lost by contact transfer very close to the surface (~99%+ within 100mtrs). Contact transfer of energy to CO2 causes momentary radiation energy to be emitted. The increase in excited molecules due to additional CO2 stimulation causes an increase in convection that causes an acceleration in upward air movement. Increased incoming solar energy causes a higher level of IR emission in the full IR spectrum that warms the surface air and causes air expansion. The resultant greater distance between molecules causes contact produced IR to survive for longer and that is what is claimed to be an increase in "downwelling" IR due to the increasing density of CO2.
An excellent article that encapsulates current knowledge of CO2 and the many absences in knowledge of the climate;
Why I Am A Global Warming Skeptic Doug L Hoffman
To summarize, Earth's climate is amazingly, mind-blowingly complex and science has only just begun to figure out how it works. While our theoretical knowledge improves and our data become more accurate with each passing year, it is safe to say that there is still more we don't know about climate change than things we think we understand. Here are some fundamental questions about the state of Earth's climate:
- Is Earth's climate warming? Yes, by around 1°C (1.8°F) during the 150 years leading up to the present.
- Do human activities impact the climate? Yes, all numerous and widespread species do to some extent (see the concluding remarks of “What Killed The Mastodons?”).
- Do atmospheric CO2 levels rise and fall with temperature? Yes, according to historical data.
- Are atmospheric CO2 levels rising because of people? Yes, it would appear so.
- Does this mean that the theory of anthropogenic global warming is correct? Absolutely not.
For the reasons given in the article above, and those described in greater detail in The Resilient Earth, I have concluded that science does not understand the climate system well enough to make the predictions that climate change alarmists keep making. Scientists continue to argue about fundamental mechanisms and the accuracy of historical data. In the absence of better theoretical knowledge and sufficient accurate data, climate scientists have filled the void in understanding with output from computer models, which are the most fickle and fallible of tools.
Consider the following main points:
- Climate is a nonlinear system.
- Not all feedback relationships are known or well characterized.
- Based on known empirical evidence a doubling of atmospheric CO2 levels will only cause a further increase of 0.2 to 0.5°C in global temperature.
- In order to achieve the temperature levels predicted by the IPCC requires amplifying positive feedback from the climate system.
- There is no compelling proof that Earth's climate system acts as a temperature change amplifier.
- Not all known factors are included in climate models.
- Models cannot predict nonlinear responses not built into them.
- Baseline data used to calibrate the models are uncertain and possibly erroneous.
- Different climate models predict different future outcomes because they make different assumption or use different values for model parameters.
- All climate models contain errors that are fundamental to their construction.
In the wake of Climategate and Glaciergate it is tempting to dismiss the theory of anthropogenic global warming as bogus science foisted off on a gullible public by a number of bad scientists. The reasons for this climate science chicanery are not clear: the torrent of grant money, the novelty of fame or simply error amplified by ego. As entertaining as the news accounts of unfolding scandal have been, it is important to remember that many serious scientists believe in human caused global warming to one degree or another. But science is a human endeavor and as prone to mistakes as any other. This will not be the first time that a majority of the scientific community believed in an erroneous theory, and it certainly will not be the last. Eventually, science will decide the fate of AGW based on empirical evidence—nature itself will provide the proof, one way or the other.
To date, climate science has not produced any incontrovertible proof that rising CO2 levels will, in fact, cause the temperature increases predicted by GCM models. The information presented above reinforces the observations I made in my earlier post, “The Crumbling Pillars of Climate Change.” The theoretical understanding is incomplete, the historic data are spotty and uncertain, and the models are not an accurate representation of the climate system. Further, models have been used inappropriately to bolster the IPCC's case—models are not scientific evidence and should not be used to predict long-term real world behavior.
The truth is, climate science uses computer models like a drunk uses a lamppost, not for illumination but for support. Even AGW supporters agree that if the only evidence for global warming were computer models, then skepticism would be entirely justified. But, while models are most definitely a sore point in the global warming debate, they are not the central point. It is the science itself that is uncompelling. Neither current scientific knowledge nor historical data prove the theory of anthropogenic global warming as put forth by the IPCC. If anything, new data and new studies reveal that current climate change dogma has got it very wrong. That is why I remain a global warming skeptic.
On CO2, the main argument put forward as evidence that CO2 is causing warming is that radiation in the wavelengths that CO2 absorbs show a reduction in OLR. If true (I have a problem with increasing volumes of CO2 emitting less radiation) it is at the very least deceptive to say it proves CO2 drives warming without considering the full range of thermal energy leaving the planet. By all accounts this has been steadily increasing.
I borrowed the following from a comment to Empirical evidence that humans are causing global warming
"Looking at Harries 2001 Figure 1B (not shown), the range 800-1000 cm-1 shows an increase in outgoing long wave that exceeds the decrease due to GHG's. This observation is also present in Griggs 2004 and Chen 2007.
Harries 2001 attributes this increase over the range 800-1000 cm-1 to 'small residual ice crystals' not fully removed from the data due to field of view differences between the detectors. This assertion is not supported by the addition of the NASA AIRS satellite.
Additionally, satellite measurements of total outgoing long wave radiation show an increasing trend with time (and CO2, although not causative).
UAH shows that there has been no statistically significant warming for 15 years. See the Air Vent. (This data can be downloaded and you can plot it yourself to verify it) RSS’s no statistically significant warming period is slightly shorter.
Figure 2C from Harries 2001 is being used to show that outgoing long wave radiation is decreasing as a result of CO2 and other greenhouse gases.
Figure 2B (not shown) indicates an increase the range 750-1000 cm^-1. The net effect is an actual increase in OLR over time. This increase is shown spectrally in the other papers mentioned as well (Griggs 2004, Chen 2007).
Although Harries 2001 writes it off as contaminated data - it is a real measurement and not an artifact (Griggs 2004). The increase has been measured in other satellite measurements of total OLR. The total OLR is increasing over time, not decreasing."
Harries 2001 (paywall) (Spectrum from the paper here)
However see CO2Science "Greenhouse Effect – Summary"
Also offsetting factors to be considered yet generally ignored -
CO2 absorption of UV that starts at 202nm
Deep-UV absorption and Rayleigh scattering of carbon dioxide (PDF)
And solar IR absorption by CO2
The Atmospheric Absorption Spectrum
The predominant absorption of near infrared wavelengths (0.7-4.0 μm) is by several vibrational-rotational H2O absorption bands. CO2 also contributes to near IR absorption by bands centered at 2.7 and 2.0 μm and weak bands at 1.6 and 1.4 μm. These features appear in Fig. 10.1b.
Again the most dominant absorption in the far IR is that of water vapor. Figure 10.3 shows the H2O absorption spectra based on use of a theoretical line shape. Superimposed on this absorption is the absorption centered at 15 μm and at 4.4 μm by CO2 and weaker bands at 10 and 5 μm. Ozone has a strong vibration-rotation band centered at 10.6 μm and a weaker band at 14 μm.
Suppression of IR emission from bodies of water in CO2's bands is said to cause a small increase in evaporation rates. The additional WV created is postulated to be a warming factor, however evaporation cools the water equivalent to the energy transferred to the air. Oceans regulate the air T so postulated CO2 addition driven evaporation must be included as an offset to warming.
There is also the factor of increasing take up not least by extending biomass, desert absorption, evolving soil fungi and bacteria and diminishing influence of CO2 additions as IR emissions by the surface reduce due to the reduction in TSI, the recent dramatic reduction in UV emission and the increase in ozone. But the UV reduction will likely cause (be causing) an offsetting reduction in cloud cover as evaporation reduces.
Reality Check CO2 (PDF) by Richard F. Yanda, Ph.D.
Carbon dioxide (CO2) plays an interesting role in the distribution of heat in the atmosphere. Confusion about its ability to influence the global temperature has given rise to misunderstanding and misdirected efforts in both science and politics.
Every discussion about a scientific topic should begin with a careful review of the principles of science that are known and universally accepted. Better conclusions can then be drawn based upon facts.
[...] It is interesting to see on this graph the numerous low points where the gaseous H2O and
CO2 in the atmosphere are absorbing those wavelengths of light, reducing the amount of [solar]
energy that reaches the earth’s surface to varying degrees.
From the PDF
web site http://getthescienceright.com/page9.php
Cold Facts on Global Warming
[...] At the current rate of increase, CO2 will not double its current level until 2255.
From the web page
Some climatologists, making assumptions about ever-increasing rates of carbon dioxide production, assert that the doubling will occur within a few decades instead of a few centuries. However, they are doing sociology, not climatology. They are assuming that fossil fuel consumption will increase drastically over current levels. This is very unlikely. The only honest way to estimate the change of CO2 levels is to make predictions based on what is happening now, not what might happen in some hypothetical future society; otherwise, we are merely inflating our predictions by indulging in speculation about future social trends.
(via Icecap) GlobalWarming: The Other Side
See John Coleman’s one-hour special on KUSI Global Warming, the Other Side here. See his part II Global Warming Meltdown here. NEW: See his latest interview with Anthony Watts here. See his latest interview with Dr Fred Singer here. See his very revealing story on Roger Revelle here. See his powerful interview with E.M. Smith here. See his other videos here.
Off topic entertainment
Ice cream by Mail Online "immaculately conceived" and "‘we believe in salivation" - humour at the genius level.sert