Start small, think big. Don’t worry about too many things at once. Take a handful of simple things to begin with, and then progress to more complex ones. Think about not just tomorrow, but the future. Put a ding in the universe.
The human response it calls for is truly heroic, requiring nothing short of rewiring the entire planet with a new generation of clean-energy technologies - and doing that very soon. . . Are we, as a species, capable of that kind of deliberate global response?