As the world's financial powerhouse, the United States has both an outsized effect on climate change relative to our population, but also power to do something about it that extends far beyond our borders. Both treaties and commercial agreements can be used to lever other nations into responsible climate policies; we've been doing this with just about everything else for our entire existence. You ever wonder why weed is illegal everywhere in the world at about the same time? Or copyright laws that destroy the public domain? We did that. We could use that power for good, as well.