A guest essayist at Watts Up With That has an interesting article. Here’s the closing paragraph (as usual, RTWT):
In summary, approximately 81% of the warming in the last century may have resulted from all anthropogenic influences, as suggested by figure 4 [see the article]. This includes water vapor, CO2, methane, nitrous oxide, and land use changes to the albedo and thermal mass. CO2 may account for as much as 52% to 56% of the contribution from anthropogenic drivers (See Figs. 1 & 2). Fossil fuel-CO2 represents less than 75% of anthropogenic CO2. If we were successful in completely phasing out fossil fuels over the next 100 years, we would have a reduction of 50% in average CO2 emissions. If the Earth is warming at a nominal rate of 1°C per 100 years from all influences, then we can hope, at best, for a reduction in temperature increase of 20% (0.54×0.75×0.50) or 0.20°C. That is to say, if the world were to phase out fossil fuels in the next 100 years the warming would be 0.80 degrees instead of 1.00°C! Unfortunately, eliminating fossil fuel use will probably not be successful in significantly reducing future temperature increases, even if it can be accomplished.
A whole two tenths of a Centigrade degree, out of a climatista-expected entire one Centigrade degree. Imagine that.