Over the last 100 years, global temperatures have warmed by about 1.33 degrees Fahrenheit (0.74 degrees Celsius) on average. The change may seem minor, but it's happening very quickly — more than half of it since 1979, according to the Intergovernmental Panel on Climate Change.
Though it can still be difficult to tease out how much climate change plays in any given weather event, changes are occurring.
In the spirit of Earth day, here's a look at our marvelous blue marble and the ways people and other living things are responding to global warming. [50 Amazing Facts About Earth]