|Mars's southern polar ice cap, seen here in true color, has shrunk in recent years due to planetary warming—similar to what's happening on Earth|
Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist Says
Mars, too, appears to be enjoying more mild and balmy temperatures. In 2005 data from NASA's Mars Global Surveyor and Odyssey missions revealed that the carbon dioxide "ice caps" near Mars's south pole had been diminishing for three summers in a row. Habibullo Abdussamatov, head of the St. Petersburg's Pulkovo Astronomical Observatory in Russia, says the Mars data is evidence that the current global warming on Earth is being caused by changes in the sun. "The long-term increase in solar irradiance is heating both Earth and Mars," he said. Abdussamatov believes that changes in the sun's heat output can account for almost all the climate changes we see on both planets. Mars and Earth, for instance, have experienced periodic ice ages throughout their histories.
Global Warming Fast Facts
There is little doubt that the planet is warming. Over the last century the average temperature has climbed about 1 degree Fahrenheit (0.6 of a degree Celsius) around the world. The spring ice thaw in the Northern Hemisphere occurs 9 days earlier than it did 150 years ago, and the fall freeze now typically starts 10 days later.