In any event, after lots of wasted time dealing with irrelevancies, I have finally simplified my argument. I have shared this simplification before, but thought I might again, given how much shrieking I hear in the air.
The primary Greenhouse Gas is water vapor. It absorbs a very broad spectrum of infrared radiation, and does so at relatively low altitudes. Adding CO2 near the surface does nothing, since that energy was going to get absorbed anyway.
Where CO2 has a marked effect is in the upper Trophosphere, and the much thinner air perhaps a mile up. It can only absorb about 10% of the radiant spectrum, but that is still a lot of energy. Without its effects, Earth would freeze and life would be impossible.
The entire argument for Anthropogenic Global Warming rests on the ideas that this layer of air can be heated enough that it warms the air below it, which warms the air below it, which warms the air at surface level.
Now, it is well known that as CO2 concentrations rises, the relative impact of each PPM diminishes. For every doubling of CO2, the relative effect is cut in half. Double CO2 once you get one unit of warming. Double it twice you get a half unit of warming, for 1.5 units. Double that, and you get .25 units, or 1.75.
It is easy to see that there is an asymptotic function here, where somewhere along the line CO2 really just doesn’t matter that much.
This link deals with this helpfully: https://wattsupwiththat.com/2014/08/10/the-diminishing-influence-of-increasing-carbon-dioxide-on-temperature/
As they point out, most of what CO2 COULD do it is already doing.
But the core point I want to make is this: in the same way that air does not easily heat water, due to their very different densities, the thin air where CO2 operates cannot easily heat thicker air below it. This means that the AGW hypothesis REQUIRES considerable heating in specific places for any effect at all to be registered at ground level, and as it happens we have highly accurate satellite data for those regions, and have for at least 3-4 decades. Those regions are not warming any faster than the rest of the atmosphere, which means that the AGW hypothesis has been falsified.
IF–and I am obviously speaking counterfactually here–AGW was in the main a truly scientific idea being advanced by honest scientists–there would be no land based measurements used at all. The entire focus would be on the one place where we have good data, and which is critical to the validation–or as it happens, the empirical falsification–of the hypothesis.
I won’t go into all the methodological problems with land based data, but will simply note that for much of the Earth NASA simply invents data. They don’t have many thermometers at the poles, or for most of the Artic and Antarctic circles. They can’t measure the ocean temperatures very well. They have no reliable means of correcting for the heat island effect for the many stations they have that actually are accessible.
So you have on the one hand satellite data which is highly reliable and relevant, and on the other ground data which is completely unreliable, and irrelevant. Even if there is warming, there is no clear means of teasing out CO2 induced warming from other sources.
The ONLY reason they continue with this nonsense is that you can use statistical models to create any data pattern you want. This is at least as old as Michael Mann’s infamous Hockey Stick, which was created using algorithms intended and programmed to create a specific result. Anything that conformed to their goal they weighted, and anything which did not got minimized or deleted.
If I might amend Mark Twain: “Lies, damn lies, statistics, and Global warming”.
Trump unquestionably did the right thing. The open question now is why so much of the rest of the world is so fucking stupid.