As as happen with the tobacco industry, similarly the fossil fools profiting from cooking the plant - they fund and have useful idiot Science deniers that want to evade and discredit expertise, because there is none in their movement: no time-tested papers, no credible alternative theories to explain climate change, no alternative models, nothing.
Thus they are loud, repetitive, resentful, mainly ad hominin attacks to try to undermine and discredit expertise.
