Mostly what's going on is that infrared that would have escaped to space at about 12 km up in the atmosphere is now partially absorbed and re-radiated by the in

Mostly what's going on is that infrared that would have escaped to space at about 12 km up in the atmosphere is now partially absorbed and re-radiated by the increased CO2 at this level. At these altitudes, the atmosphere is cold and dry so injecting more CO2 has a knock-on effect: https://history.aip.org/climate/co2.htm https://history.aip.org/climate/co2.htm > "Improved physics theory and precise laboratory measurements in the 1940s and after encouraged a new way of looking at the absorption. Scientists were especially struck to find that at low pressure and temperature, each band resolved into a cluster of sharply defined lines, like a picket fence, with gaps between the lines where radiation would get through.(24) As Hulburt and Callendar had claimed, the most important CO2 absorption lines did not lie exactly on top of water vapor lines. Instead of two overlapping bands, there were two sets of narrow lines with spaces for radiation to slip through. So even if water vapor in the lower layers of the atmosphere did entirely block any radiation that could have been absorbed by CO2, that would not keep the gas from making a difference in the rarified and frigid upper layers." However, this CO2 at 12km only accounts for about 1/3 of the warming - what happens is that the warming is amplified by more evaporation (due to increased warmth) which injects more water vapor into the atmosphere (from the oceans and land evaportation) and that's the other 2/3 of the effect more or less. It is a slow change, but steady. It's entirely possible that humans will be able to adapt to much of the change, assuming we stop pumping fossil CO2 into the atmosphere within the next few decades or so.