Answer: Infinitesimal

The IPCC now agrees. See the IPCC Technical Report section entitled Global Warming Potential (GWP). And the GWP for CO2? Just 1, (one), unity, the lowest of all green house gases (GHG). What’s more, trace gases which include GHG constitute less than 1% of the atmosphere. Of that 1%, water vapor, the most powerful GHG, makes ups 40% of the total. Carbon dioxide is 1/10th of that amount, an insignificant .04%. If carbon dioxide levels were cut in half to 200PPM, all plant growth would stop according to agricultural scientists. It’s no accident that commercial green house owner/operators invest heavily in CO2 generators to increase production, revenues and profits. Prof. Michael Mann’s Bristle cone tree proxy data (Hockey stick) proves nothing has done more to GREEN (verb) the planet over the past few decades than moderate sun-driven warming (see solar inertial motion) together with elevated levels of CO2, regardless of the source. None of these facts have been reported in the national media. Why?