I would expect India and China's per capita consumption needs to continue to rise over the next century as their economies grow and improve. That's almost 3 billion people...almost half the world population. If you want to really make a mark, there's opportunity there. I know there's opportunity in the U.S...but U.S. has already reduced it's carbon output by 25% since 2005:
https://en.wikipedia.org/wiki/Greenhouse_gas_emissions_by_th...