,, cars do. Don't breath, you exhale green house gas. Move out in to the wilderness life off the land. Don't build any fires they give off green house gas. Am I extreme?? Not any more the Al Gores misleading movie.
At this point in time China is the BIG polluter and that is when most of this high tech stuff is made. If you want to help plant a lot of trees, they turn Co2 in to OXYGEN. John