Take thirty seconds to look at this time lapse video produced by NASA, paying special attention to the last ten seconds, which cover the last 40 years. Thirty seconds. Not too much to ask, even for busy people like us.
Watching this video won't change the world, but it might help change your mind about the reality of global warming. And once you accept that reality, it won't be long before you are wondering how it got this far. But don't expect to hear the Republican presidential candidates debating this topic, unless it is to outdo each other in their denials of the science and the threat.