I only put the question mark because I had to. Do some research. The US is the only country on the planet that talks about it. And we have the best air. I believe in recycling, but really, we are on the verge of another ice age. Celebreties need a cause and they chose this one. One example...Julia Roberts put in her own treatment plant for her water...what does that cost her neighbors...you are seriously foolish if you are buying into this. Take a class. The Earth gets warmer and colder and there's nothing you can do about it! If it did get warmer from exhaust fumes, that would make more clouds, and the Earth would cool.