Few things. There is a reason that the future that most people think of is rather short. The future is unknown. Too much consideration into the unknown and you basically end up with mindless speculation. 100 years ago if you would have told people the size of modern cities and how much people moved around those people would wonder how those cities dealt with the tremendous amount of horse manure that must be the result.
I don’t think it helps the climate movement as a whole to act like a few degrees here or there can doom human beings as a species. There is zero evidence that that is the case. Attempting to scare people with what amounts to an almost laughable threat makes them stop listening to you. Human beings are very adaptive. We have humans living on all continents including Antarctica at all times. “Climate change” is not going to destroy either human beings or the planet. By almost every measure we are treating the environment better and better as technology improves(seriously look up measures over time of air quality and other pollution data) and life becomes easy enough for us generally that the environment is important to us. This will happen to the rest of the world also as they modernize. So why fight for something that is happening anyway.
Climate change generally is a terrible global cause. Dictators can take vast volumes of money in claiming it to be for climate change and then build palaces to themselves with it. The reason is that climate change isn’t really a tangible good. We would be better off helping those third word countries with things like sanitation and clean water. Tangible things that would improve their quality of life and real world outcomes.