[rlmorel]

One of the most critical flaws in the role of CO2 is assuming that, at the levels in our atmosphere we see it at, increasing it is the same as painting a window. Global Warming advocates say the behavior at these levels is apparent in the same way. The first coat of paint will somewhat cover the window, but light will still come in. Each subsequent coat of paint will produce a linear response until no light comes in through the window.

At these levels of CO2, that is a completely false premise. One of many.

As critics, too many of us fall into the trap of saying that CO2 doesn’t have the effects it is credited with because it is only .004% of the atmosphere. Supporters will immediately fire back that science is full of things that have effects apparent at those low concentrations.

[palmer]

As you suggest, CO2 sends less and less heat back to earth at its concentration increases (logarithmic curve). The alarmists then say that water vapor will increase or clouds will change to be warmer or other nonsense. Not only do they not understand weather, but they don't model it either (the GCM's are too coarse in space and time).

As for the trap, it is true and has captured quite a few skeptics. I sometimes think some alarmists mount disinformation campaigns to make skeptics look stupid. But then I realize a fair number of skeptics don't know their science.