Climate change is already out of control, to have been able to stop it we would have needed to use 100% green energy worldwide back in 2010-12, and not just look at the paris climate agreement, (decrease C02 emition by 20% by 2020) and haven stopped the entire meat industry (the meat industry is doing around 20% of the total pollution to the environment) We are already pass the point of no return.
Out only option right now is to invent some kind of technology that almost works like magic than can undo the damage we have done to the climate, we are no longer at a state where just by scaling back or polluting less we can "fix" the damage we have done to the climate...
by 2100 they expect most of the middle east no longer being viable for human life... we are gonna have wars over water... if you think the Syrian migrant crisis was bad where not even 10 million people trying to flee to Europa and it fucked over the immigration in a lot of countries then try and guess what will happen when more than 1 billion people either flee from their countries or die if they stay...