For them, in very very summary,
1 / climatic warming, very real, is one of the cycles like the earth has known several since 650 000 years (or more, but the ice cores have been studied until this date
2 / despite the very real increase in anthropogenic GHGs (CO2, CFCs, Methane), the effect of these GHGs in the greenhouse effect (fortunately it exists because otherwise we would be called Mars, and would not be not there to discuss it) is at most 2%, which is probably too much, but good ..;
It’s Allègre who would be happy to read that !!! ... he who broke when he said that we were doing too much !!
I believe there is scientific agreement that there would never have been such FAST warming based on the interpretation of arctic ice cores.