Another study by the U.N.-backed International Polar Year program, which found that icecaps at both the North and South Poles are melting at unprecedented rate. The report, compiled by scientists from more than 60 countries, also says that the shrinking of polar and Greenland ice is fueling a rise in sea levels and the potential for dramatic changes in the global climate system. The authors say the Arctic permafrost also reveals larger amounts of carbon than expected that, with further melting, could release more greenhouse gasses into the atmosphere.
Temperatures at the South Pole are rising faster than expected. "Just within the last few months we've seen confirmation that the continent of Antarctica has been warming. And it's been warming at a rate of almost 0.2 degrees Fahrenheit per decade, comparable in pace to much of the rest of the Southern Hemisphere." The U.N.'s Intergovernmental Panel on Climate Change says if CO2 levels are left unchecked, the earth's temperature could rise several degrees by the end of the century.
Scientists who are skeptical of the severity of global warming contend that there is no way to measure the impact of human activity on climate and that no one knows how much warming will occur or how it might affect the earth. Some experts suggest that global warming may be part of natural climate cycles that humans can do little about.