Overall, the earth is in a cooling trend, not warming!
Take a look at this chart from the John Baez Temperature article that I referred to yesterday. Note that “today” is at the top of the image and that 4600 million years ago (Ma means “millions of years ago”) is at the bottom of the chart. That means that, overall, we are in a much cooler climate than the earth has been in the past!
The chart originally comes from: Barry Saltzman, Dynamical Paleoclimatology: Generalized Theory of Global Climate Change, Academic Press, New York, 2002, fig. 1-3