That said, I do have a suggestion for a straightforward way to lessen future harm caused by global warming that I haven't seen mentioned elsewhere:
Bring down the birthrate in Bangladesh, fast.
The logic is this:
If global warming is happening severely enough to partially melt polar ice caps and thus raise sea levels, the most severely impacted country would likely be Bangladesh, which topographically resembles the Mississippi Delta that took such a hit from Katrina in 2005: low-lying land vulnerable to big storms off the ocean. The current population of Bangladesh is 150 million and the total fertility rate is 3.09 babies per woman. The U.S. Census Bureau forecasts that the population of Bangladesh will almost double between now and 2050, when it will reach 280 million, assuming half of them aren't washed out to see in a big cyclone.