How much warming can we expect from CO2? Do the IPCC overestimate climate sensitivity?

The term climate sensitivity (specifically due to CO2) is often “expressed as the temperature change in °C associated with a doubling of the concentration of CO2 in Earth's atmosphere” from its pre-industrial concentration of 280ppm to 560ppmv.

Climate sensitivity estimates rage dramatically, depending on the paper. Below is a table I put together some time ago comparing climate sensitivity estimates in various scientific papers to that of the IPCC. ECS stands for “equilibrium climate sensitivity” and TCS stands for “transient climate sensitivity”.

The IPCC appears to overestimate climate sensitivity. They estimate that ECS is 3°C and TCS is 1.7°C. The average, from all of the 33 papers listed below (some of which are rounded off), including the estimates from the IPCC, is 1°3C.

What are your thoughts? Should we be worried about human-induced climate change? Are some of the studies cited below unreliable? How much warming can we expect from a doubling of CO2?

a reply to: Nathan-D

There's no point in asking people to predict the future of a climate about which we do not know all of the variables that affect is ebb and flow of temperature.

Too much is based on assumption, as proven in the reality that predictive climate models are generally wrong and over-exaggerate the warming of our climate in the future.

a reply to: Nathan-D

Should we be worried about human-induced climate change?

Of course we should.

The IPCC and others aren't helping though with the continuous beating of the CO2 drum.

The following quote more or less sums things up.

There's no point in asking people to predict the future of a climate about which we do not know all of the variables that affect is ebb and flow of temperature

Part of the problem is that some very significant climate influences have been left by the wayside as a result of a singular focus on CO2 as the primary climate culprit.

The IPCC is just another money making endeavor for the UN. (Think UNICEF and Oil for Food)
Do research on the first head of the IPCC
A railroad engineer from India with a degree in business
Speaks volumes.