India, and large parts of China and Africa will be heavily impacted by climate change, far more than the US. India and China are already taking it very seriously - building tons of renewable energy capacity, high taxes on fuel etc. And that's with the world's largest polluter (the US) not doing anything, and in fact denying there's even a problem.

It would be better for everyone if everyone stops polluting. But rich countries, that are mostly in northern latitudes and less affected by climate change, aren't taking any action. So it makes sense for poor countries, largely in places affected by climate change, to try to develop faster by any means possible so they can better-handle the coming disaster.

Whereas if rich countries take the problem seriously, add carbon taxes and tariffs and whatever other measures needed, they have moral, economic, legal, and even military levers against those who don't sign on. Poor countries can develop their economies with renewable energy and not worry as much about preparing for climate-fueled crises.