Climate Change & Global Warming

Natural variability can explain much of Earth's average temperature variation since the end of the last ice age, but over the past century, global average temperature has risen from near the coldest to the warmest levels in the past 11,300 years.

Thursday, April 1, 2010

  • Curiosity is a cruel master, says Dave Bertelsen. Over the past 25 years, he has hiked over 12,000 miles through a desert canyon, just to see what was blooming. He found a few surprises along the way.