Military research requires clearance which foreign nationals can’t get anyway.

Well of course. The US is a massive oil producer. Why would they give up such a key geopolitical advantage? Plus, models say that the emerging powers (China, India) and the big regional blocs (Europe, Southeast Asia, Africa, South America) would all be hit harder by climate change than North America. From a geopolitical perspective, the US should absolutely sandbag climate efforts and do the minimum necessary to not look like they’re completely indifferent to the crisis.