Carbon dioxide absorbs the infrared radiation that the earth emits, trapping it before it leaves the planet. This warms up the atmosphere, making the earth a haven for life. Obviously, then, the more carbon dioxide we put into the atmosphere, the warmer it will get, right? Not necessarily! As I tell my high school and university students over and over again: Science isn’t simple! As a result, conclusions that seem “obvious” to most people (even most scientists) are often absurdly wrong. A recently-produced study that has not yet been published in the peer-reviewed literature makes this case about carbon dioxide and global warming, aka “climate change.”
The “obvious” conclusion that more carbon dioxide means more global warming ignores the fact that carbon dioxide doesn’t absorb all the infrared radiation it encounters. Instead, it only absorbs specific wavelengths. In addition, the amount of each wavelength that carbon dioxide can absorb varies with wavelength, the temperature at which the absorption happens, the concentration of the gases in the surroundings, etc., etc. Because of such effects, there comes a time when adding more carbon dioxide to the atmosphere has a negligible effect on the amount of infrared radiation absorbed. When that happens, you have reached saturation, and increasing the amount of carbon dioxide will not increase the atmosphere’s warming.
Now all of this is well known, and most global warming models attempt to include these effects in their calculations. The problem is that they treat them in a crude way. This is understandable, since a model that is trying to simulate the entire atmosphere has to consider a lot of things. As a result, most of them are treated crudely so that the model doesn’t become overwhelmingly convoluted. That’s where this unpublished study comes in. The authors test the effect of treating the science related to saturation crudely, and they say it renders the models pretty much useless when it comes to understanding how carbon dioxide affects the present atmosphere.
How do they come to this conclusion? They consider more than 300,000 different infrared wavelengths that carbon dioxide and other greenhouse gases (water, ozone, methane, and dinitrogen oxide) absorb. They compute how much the gases will warm the atmosphere by absorbing each wavelength. First, they make the computation without considering details like the temperature, the other gases in the atmosphere, etc. This is roughly equivalent to how current models treat the situation. Then, they do it considering all those details, using the present makeup of the atmosphere. They find that in the present atmosphere, the amount that more carbon dioxide can contribute to global warming is 10,000 times smaller than what current models assume. The same can be said for water vapor. For carbon dioxide and water vapor, then, the atmosphere is very, very close to saturation. As a result, more carbon dioxide and water vapor in the atmosphere will not warm the planet in any meaningful way. Ozone, dinitrogen oxide, and methane are also close to saturation, but not nearly as close as carbon dioxide and water vapor.
How do we know that their analysis is correct? We don’t. When they compare their calculations of how much infrared radiation is being absorbed for each wavelength to what satellites have been measuring, they see virtually no difference. Thus, their calculations seem to reflect reality very well. However, I am not very knowledgeable about the details, so there might be fatal flaws in their analysis that I am not seeing. Once again, science isn’t simple. I really hope this gets published in the peer-reviewed literature so that experts can weigh in on the conclusions. Unfortunately, I am not confident this paper will get that far. If its conclusions are correct, then there is absolutely no basis for the fear-mongering that surrounds carbon dioxide emissions. There are so many scientists whose careers have been made based on that fear-mongering, they may simply keep the paper from being published.
Fortunately, science is self-correcting. One way or another, we will figure out the details related to this issue. It might take longer than it should, and it might be after terrible decisions have been made based on faulty climate science, but at some point in the future, we will find out whether or not these authors are correct. I hope it is sooner rather than later!
Dr. Wile, I had previously read in multiple sources that the CO2 levels are already at the saturation level when it comes to absorption of IR radiation. Here is an example:
http://clivebest.com/blog/?p=1169
“In fact already 95% of the radiant energy is absorbed by CO2 at pre-industrial levels leaving a maximum of just 5% for any increase you like.”
I’d be curious to know what you think of this blog post written in 2010.
I had honestly never heard that. I think that the paper I am discussing here mostly addresses the two reasons your link gives after, “There are two main arguments why global warming is important despite apparent saturation when man adds CO2 to the atmosphere.” It shows that neither reason is valid.
Always something to learn or add to knowledge here. Thank you! As someone raised in agriculture, I understand CO2 is as vital to plants as nitrogen. When someone tries to use Venus as an example of global warming, I ask where’s Venus? Is it closer to the un than earth? And what about Mars? It’s 95% CO2 and an icebox. Because earth is covered in water and plants, and in the perfect place in the system, CO2 and methane are self-correcting. More CO2, more plants. Methane is food for fungi which break it down to nitrogen and other components. Walk in His beauty
I like your optimism, though it getting harder to share it. A Catholic bishop, Archbishop Vigano, recently warned in a letter that society is geared towards what is known as “The Great Reset”. If you look this up on YouTube it’s pretty plain to see the Great Reset videos (put out directly by the world economic forum) do plan to radically change society based on Global warming and social justice.
At some point you have to wonder if the truth stands a chance in the face of such technocratic power. I do appreciate people like you who keep these blogs. We need as much common sense as possible right now.
I finished my first pass reading the linked article. It reminds me of when I was studying thermodynamics in college. The math isn’t simple. It’s easy to overlook one small thing that throws everything off. I’ll get back to that at the end of my comment.
They say that radiative forcing by greenhouse gasses is already saturated. Nevertheless, they still say that the “climate sensitivity” of doubling the concentration of CO2 is 2.2 or 2.3K, which is consistent with global warming alarmist predictions. I that guess that nod to consensus enabled them to get this paper published.
However, you have to pay very careful attention to the terminology. “Radiative forcing” and “temperature change” are quite different. Here’s what they say about it: “The forcings due to instantaneous changes of greenhouse gas concentrations can be calculated quite accurately. Temperature changes induced by the forcings are less clearly defined because various feedbacks change the temperature profile of the atmosphere”
In other words, they’re very confident in their calculations of “forcing” but the effect of this forcing on temperature is a completely different story. “Less clearly defined” should be translated as “don’t really know”. The numbers they came up with assume either fixed absolute humidity or fixed relative humidity, both of which are huge simplifications that make the calculations simpler but not accurate. The water feedback model isn’t really proven.
But another even bigger thing people might miss, although it is in the first sentence of the conclusion, is: “This work examined the transmission of infrared radiation through a cloud-free atmosphere from the Earth’s surface to outer space.” Please note: CLOUD FREE.
It turns out that modeling the effects of clouds on radiative transfer is so complex that they completely left it out. But that doesn’t mean it’s not super important! Clouds definitely affect heat transfer. So even their “radiative forcing” calculations that they are so confident in are completely unrealistic. Feed those unrealistic forcing numbers into an oversimplified water feedback model and you don’t get a reliable answer.
The only honest answer to the question “what is the effect on climate of doubling the concentration of CO2 in the atmosphere” is that God knows and we don’t. My guess based on other things scientists have said about the earth’s climate in the past (ice ages, giant prehistoric forests, etc.) is that climate change is normal and natural. We should worry more about things that are under our direct control, such as how much money we spend, how we treat other people, etc.
Thanks for your analysis. The way I understand it, the climate sensitivity they report is for the initial calculation (optically thin atmosphere, where there is negligible saturation of the absorption bands). So what they are saying is that they are equivalent to the standard models before they consider saturation. Thus, their “baseline” is similar to the standard models. I do agree with your other points.
Thanks for posting this, Dr. Wile. I recently attended a lecture presenting data that seemed to make a convincing case that human activity, specifically our contribution of greenhouse gases, is the primary mechanism responsible for warming of average global temperatures. I am referring specifically to a graph in this link about 2/3rds of the way through the article titled, “Global temperatures: Human and natural factors, 1850 – 2100.” The graph plots the impact of various factors on global temperatures compared to observed global temperatures over time. According to the graph, the contribution of greenhouse gases matches the observed temperature increase very well, while all other factors in isolation (ozone, volcanoes, aerosols, etc.) do not. This seems to imply that greenhouse gases are the primary factor explaining the observed increase, which implies it is human-induced.
Do you think these data make a good case for human-induced global warming? Are there any important data missing in your opinion?
They do not make any kind of case at all. First, there is a problem with the data. The data involve surface temperatures, with which there are a number of problems. These data are regularly adjusted, homogenised and mucked around with. The more reasonable data to look at are satellite temperatures, which sample the entire globe. Their record is significantly different. Second, there is a problem with the “simple model.” It’s exactly that. Far too simple. Unlike the article claims, the simple models don’t come anywhere close to the more reasonable models. As you can see, the vast majority of global climate models produce much more global warming than the data indicate.
If I make a simple enough model, I can reproduce any data I want to reproduce. Thus, the simple model just confirms what the modelers want to believe, because it ignores all the inconvenient realities. When real data are compared to realistic models, we see that if there is any warming caused by carbon dioxide, it is small.
Thank you for your reply and the references. I might be missing something, but the graph in the link I originally posted seems to suggest that temperatures rose by roughly 1.3 degrees C over a period of ~170 years (1850 – 2017). You said that temperatures measured by satellites are “significantly different,” but the graph you referred to shows a rise of ~0.8 degrees C over an even shorter time period, 41 years (1979 – 2020). This seems to be an even faster rise. What do you mean when you say the satellite temperatures don’t show the same rise in temperature over time? Am I misinterpreting something in either of the graphs?
Look at the trends. In the BEST data, the rise is nearly constant after 1979. In the satellite data, there are several flat parts to the graph. More importantly, the maximum at 2016 in the satellite data is just over 0.1 C higher than the maximum at 1998. For BEST, the maximum at 2016 is more than 0.3 C higher than the 1998 maximum. In addition, current temperatures on the satellite graph are LOWER than the temperature in 1998. In the BEST graph, they are higher. So the satellite data show a more steady global temperature, while BEST shows more warming. This is the standard thing that all climatologists know but only the honest ones discuss. The satellite data and the surface data do not agree.
IMHO, the satellite data are the only data of importance in global warming because (a) They are the only truly global temperatures and (b) They measure the temperature of the atmosphere, where global warming is supposed to be happening.
I understand what you’re saying about how the trends differ between the land temperatures and satellite temperatures, and why the satellite temperatures are a better measurement. But it still seems that averaged over the last 40 years, the satellite graph exhibits a gradual rise in global temperature. There are fluctuations, but overall, there is an increase. How should we interpret this? Does this mean there is warming to some extent? Can we reasonably conclude anything about temperature change over time from this graph?
Yes, there has been a gradual increase in global temperatures, just as there was in the middle ages. We don’t know how much of an increase has happened, because our temperature measurements don’t agree. We also have no idea how much is natural and how much is the result of human activity.
Thanks for bringing this paper to our attention. I have reposted your blogpost:
https://georgesjournal.net/2020/11/08/a-robust-climate/
Thanks. Nice post.