Global warming really can't be pinned on any one specific thing, but it's largely due to an increase in greenhouse gases that have started to deplete the ozone layer. There are many causes of global warming that really deserve more attention than the commonly known and often blamed, like cars and coal fired plants.
What else contributed to global warming? Things like the popularity of beef, use of aerosol, and the invention of plastic have led to a different mentality that has caused a lot of destruction on the environment, and eventually our atmosphere, too. Sure, you might be able to refute a couple of these facts, but how about 50 of them? Read this page on the causes of global warming to get the real facts on what's causing these changes to the ozone.