I don't blame the scientists who, in the 1970s, were predicting, based on the best data they could acquire at that time, predicted massive and potentially catastrophic global cooling. I don't think there were any nefarious motives behind their pronouncements; they simply made a mistake.
Fortunately, their mistake was not compounded by governments which would use their authority to force massive changes on their citizenry to 'solve' a 'problem' which, further investigation would prove, did not exist. What might the damage to our current climate be if we had taken deliberate action to artificially warm the planet in the 40 years since that exact suggestion was made?
There is little doubt that, for some portion of the scientists who could best be described as climate change hysterics, there is a political and ideological agenda at work. I do not think that describes all of them or even most of them, but it clearly does describe those with the loudest voices or the largest platforms. There can be no other reason why the Paris climate deal required the United States to essentially stagnate its economy by immediately forcing enormously disproportionate cuts in so-called "greenhouse gases" while allowing nations such as China and India to continue increasing the same dangerous greenhouse gases for up to 13 more years before instituting even modest reductions. If the situation is truly as dire as the hysterics claim, the time for reductions is NOW for EVERYBODY, not now for some (or one) and 'eventually' (if ever) for others.