Global Warming 101

Scientists say that if you want to gauge the affects of global warming in the future, keep your eye on the Arctic. NASA images reveal that Arctic sea ice has been melting drastically over the last 25 years. One study found almost 400,000 square miles of sea ice is already gone. As rising temperatures melt away glaciers, sea levels around the world are rising.

That could spell disaster for the over 100 million people living within three feet of sea level. Some coastline villages like Point Barrow are slowly falling into the rising sea. The loss of all that ice in the Arctic could mean hotter and more deadly summers for the rest of us. If the temperatures continue to rise, some scientists are predicting an epidemic spread of infectious diseases like malaria and cholera. Warmer summers have produced massive amounts of tree-eating bugs, like the spruce bark beetle, which have already destroyed 4 million acres of Alaskan spruce.

"It's going to bring about record heat, record drought, flooding in some places and more intense hurricanes like the ones that we've seen recently from Katrina," says Dr. Oppenheimer. "In addition, it causes the sea level to rise. It's going to eat away at the coastlines. Destroy beaches. Take away homes. This is the kind of world that we're going to hand off to our children if we don't do something soon to slow global warming."