The Climate Change Cultists are hiding their real agenda behind their stated arguments.
Their real agenda is twofold:
1) CO2 is plant food. More plants equals more food equals more people.
2) Plentiful fossil fuels would enable many third world countries to rise out of poverty. Less poverty equals a lower mortality rate equals more people.
You see, the Climatologists are the same people who were screeching about "overpopulation" for years and years. They were hoping that frightening human beings with death and destruction and mass starvation would cause them to quit procreating. When that didn't happen, they had to come up with a Plan B - which took the form of Global Warming. And when that turned out to be a joke, they changed the name to Climate Change because it never occurred to them that the planet might actually stop warming at some point. Leftists are really horrible at thinking one step ahead (see every failed program that they've ever instituted).
What also apparently never occurred to them (see above) was that, as populations become more prosperous, they procreate less. Europe's birthrate is well below the replacement rate, which means that they are dying faster than they're replacing themselves. Hence, the need to import "migrants" (aka young, male Muslim invaders) to do the work that they don't have the people to do.
America isn't much better off: we're barely above the break-even point when it comes to sustainable birthrate.
So the Left is either ignorant of the above facts (a very real possibility), or they just can't wait that long and prefer to starve the lowly vermin hordes of the third world, thus reducing the population (also a very real possibility). I would place my money on the latter: the Left has never had any qualms about killing people off by the millions for their vision of the Glorious World of Next Tuesday!
And, of course, an added benefit would be to bring Western Civilization and Capitalism crashing down. That would just be the cherry on top for the self-hating western Leftists.