I ran across an article, in The National Business Review (NZ), that (attempts to) explain why the climate is not highly sensitive to CO2 warming.
In December last year . . . (the author) heard . . . a paper . . . that showed while the IPCC models predict that greenhouse gases would produce an extensive "hot spot" in the upper troposphere over the tropics, the satellite measurements show no such hotspots have appeared. . . .
a large part of this discrepancy is the result of some basic errors in the IPCC's assessment of the Stefan-Boltzmann equation. When they applied their revised factor to the effect of greenhouse gases, the temperature rise was about a third of that predicted by the IPCC. . . .
The findings that the predicted "tropical hot spots" do not exist are important because the IPCC models assume these hot spots will be formed by increased evaporation from warmer oceans leading to the accumulations of higher concentrations of water vapour in the upper atmosphere, and thereby generating a positive feedback reinforcing the small amount of warming that can be caused by CO2 alone. . . .
The new Nasa Aqua satellite is the first to measure the effects of clouds and rainfall. Ron Spencer's interpretation of the new data means all previous models and forecasts are obsolete. . . .
There is a mechanism at work that "washes out" the water vapour and returns it to the oceans along with the extra CO2 and thus turns the added water vapour into a NEGATIVE feedback mechanism. . . .
The IPCC models assumed water vapour formed clouds at high altitudes that lead to further warming. The Aqua satellite observations and Spencer's analysis show water vapour actually forms clouds at low altitudes that lead to cooling.
Furthermore, Spencer shows the extra rain that falls from these clouds cools the underlying oceans, providing a second negative feedback to negate the CO2 warming. . . .
(Thus) The climate is not highly sensitive to CO2 warming because water vapour is a damper against the warming effect of CO2.
I am not qualified to endorse these findings, but if true they would invalidate all the concern about global warming and make the future much less of a concern.