What if they turned their attention to monetary reform ?
Everyone would have a lot more money and live much better and tend to have fewer children. This would solve the dreaded (yet ridiculous) notion of overpopulation. The earth would be safe from over population.
Honest money would mean fewer, if any wars. Our wars are fought for money, just like wars were fought for money in the Republic Of Plato, and ever since. Our banks want to print everyone's money and those countries that cannot be coerced or corrupted into doing so get bombed. Its just they way the world works. If we had honest money we would have fewer wars and stop having to build the stuff all over again that got blown up and stop having to build and operate things like tanks, bombers and battleships.
Honest money creates a smaller political class and therefore bad ideas that seem to serve the environmental interest but really just serve to expand and fatten an existing political class would be practically non existent. Stupid ideas like solar and wind farms would not come to fruition because they wouldn't be subsidized. (An idea needs government subsidization because it is a bad idea.) A smaller political class would result in smaller taxes and less corruption.
That could get the snake eating its own tail.