You claim that it's about the science and that economists should have virtually no say in anything. So I'll start there.
Even if I conceded that the science backs your position on the climate changing, that still doesn't mean that leftists are going to be able to solve the issue with mass wealth transfers, taxation or anything else that the left tries to scam from people based on a niche group of people paid to spread their doom and gloom about the end of the world. This is an economics issue not a science issue
I believe the people behind this push to reinvent the economy are at their core bad people. So there's that aspect.