Environmentalists are much too concerned with planet earth. Their geocentric attitude prevents them from seeing the greater picture -- lots of planets are much worse off than earth is.
If you're environmentalist, you need to go into space to improve the situation of these poor little planet worse of than Earth. There are cute little planets, such as Mars, or Venus, with ozone holes bigger than Earth, which are 100% poluted with CO2. Go clean these planets please!