> that doesn't boil down to a new version of first world colonialism that tells the undeveloped world they missed the boat and now can't catch up because we've already wrecked the environment on their behalf.

When the first world started burning oil and coal, solar panels and nuclear reactors didn't exist. Now they do, and undeveloped countries don't have to invent them again in order to use them. This is cheaper than what first world countries have to do because they don't have to pay to build a coal-fired power plant only to shut it down while it's still functional and build a solar farm to replace it. They can just start with the solar farm.