Global warming is the century long rise in the earth’s climate system. The planet’s climate system includes surface, air and ocean temperatures. According to NASA, the average global temperature on earth has risen 1.4 ºF since 1880. It doesn’t sound like much, but a 2 degree downward shift in temperature was enough to send us into an Ice Age. Plus, 2000-2009 was the hottest decade on record. Ever.