Michael Mann claim: "As to the quality of Happer’s climate science, well that’s hard to speak to because he doesn’t actually do any climate science, and never has."
Climate Depot response: Mann is massively incorrect on this key point. Claiming Dr. Happer "doesn’t actually do any climate science, and never has" is an outrageous distortion of science and Mann should retract this claim. Former Harvard Physicist Dr. Lubos Motl responds to such charges about Dr. Will Happer: "When it comes to the main physical effect that is supposed to drive "climate change", he's not only an expert. He's one of the world's leading experts."
Mann: "The science doesn't support this the best carbon cycle scientists who have studied this problem say 'yeah there's a certain amount of methane that we it could be mobilized and it will add to the warming, but it's a small contribution compared to the warming we are causing by the burning of fossil fuels.'"
Real-world observations contradict Mann’s claims: Dr. Mann claims that “it’s not rocket science” that global warming has led to “unprecedented” extremes in droughts (too little precipitation) and floods (too much precipitation). He insists that we must take “concerted action” to mitigate our use of fossil fuels so as to avert these “disastrous” and “devastating” extreme weather consequences. Mann classifies those who disagree with him about the link between AGW and these extreme weather events as “climate deniers”.
New study, "The Medieval Climate Anomaly in South America," published in the journal Quaternary International, October 31, 2018: "MCA (Medieval Climate Anomaly) warming in South America and the NH appears to have occurred largely synchronous, probably reaching comparable intensities."