We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
Here are the two facts about CO2 absorption that is often missing in the debate. 1) There is a maximum amount of absorption that we can expect from CO2, beyond which increased CO2 will have no effect on global warming, and we are getting close to it and 2) The absorption by CO2 is a diminishing relationship with CO2 concentration. This means that if the first doubling has X effect on world temperatures, the next doubling has much less than X effect, etc.
What this all means is that the effect of CO2 on warming will max out in the coming decades, and the total effect on world temperatures will be small, say a degree or two. And, believe it or not, most global warming advocates agree with this.
So how do they get big warming forecasts? Well, they assume positive feedback loops. For example, they assume 1 degree of CO2 caused warming will result in a bunch of water vaporizing into the atmosphere. Water is a much more powerful greenhouse gas than CO2, so they get models that say 1 degree of CO2 warming causes an extra 3 degrees (for example) of H20 driven warming. This is how they get the nightmare forecasts. The take two degrees of CO2 warming and drive it up in their models with these hypothesized positive feedbacks and get eight degrees of warming.
The problem is that if our understanding of CO2 warming on a scale of 1-10 is a 7 (which is probably high) our understanding of these positive feedback loops is about a 1. We have no proof of them, and in fact we don't observe these effects in recent history. In fact, some of these loops could actually work the other way around - ie higher temperatures could cause water to form more clouds, which would cool things off. For water, therefore, we don't even know the SIGN of the feedback, much less the magnitude. But all the models you ever hear of in the press assume this loop is positive and big. Because no one is funding or giving any love to scientists who come up with a small number for warming.