If you actually look at the the arguments of the skeptics, you would see that they are not denying anything of a scientific nature.
What does the Science say that so many scientist agree will related to AGW?
From my perspective (nearly 4 decades in advanced R&D), the science is that CO2 is a greenhouse gas,
and the currently accepted forcing number of 3.71 Wm-2 for doubling the CO2 level is likely accurate.
While the science may be correct, that alone would not mean catastrophic changes to the climate.
You see, Catastrophic AGW is not one concept but two!
The First concept is that if we double the CO2 level, the energy imbalance at the top of the atmosphere would increase
by 3.71 Wm-2, and that this would force the surface temperature to increase by about 1.1 C.
The second concept (with much greater uncertainty), is that the warming from the forcing would then be amplified
to produce somewhere between minimal and catastrophic warming, (1.5 to 4.5 C).
When scientist look at the climates response to past levels of CO2 increase, and estimate what the eventual
warming will be, based on observations, most estimates fall at 2C or below.
( This includes work don by the lead authors of the last IPCC report.)
https://www.ethz.ch/content/dam/eth...documents/group/climphys/knutti/otto13nat.pdf
I can tell you I am skeptical that the amplified feedbacks have a high enough gain to reach the predicted 3C mark.
What would make me skeptical? if the amplified feedbacks exists, then they would amplify any warming, not simply CO2 warming.
This is important because the climate has warming about 4 C since the end of the last ice age, and it warmed,
.2 C between 1880 and 1940.
In climate science, it is known that there is a time lag between the input and result of a climate changing event.
This time period, has been theorized anywhere between 6.6 and 1000 years.
Recent studies, say the average time period is about 10.1 years.
The time lag between a carbon dioxide emission and maximum warming increases with the size of the emission - IOPscience
But this means that the gain of the climate amplifier cannot be very high.
If the gain were high, and the time period were 10.1 years, we would all already be dead from the .2 C pre 1940 warming.
Consider if the final ECS were 3C? That would mean that the gain was 3/1.1=2.72.
If the gain were 2.72 and the cycle time were 10.1 years, then the .2 C pre 1940 warming,
then by 1960, we would have already seen more warming that has occurred.
Skeptical Science uses a 40 year latency, so by 1980 the .2 C would have become .54 C. which would be on track
to be 1.48 C by 2020. and these numbers do not take into account the know CO2 forcing since 1940.
The math says the gain cannot be that high, and this is supported by the lower findings from observation data.
