Tom Schroeder, a University of Hawai meterologist and director of the Joint Institute for Marine and Atompsheric Reseaerch, stands somewhere in the middle of the issue. The most commonly cited prediction, from the Panel on Climate Change, is that surface termperatures could rise 6 degrees over the next 100 years, and sea levels could go up a foot and a half, subjecting coastal cities to flooding and catastrophic storm surges. Schroeder said he sees no evidence that the Earth is warming as fast as alarmists claim. And global climate is so complex, it's foolish to assume it can be predicted with much accuracy, he said. The big bogeyman in global warming discussions is human production of greenhouse gases, such as carbon dioxide.
Greenhouse gases are ones that tend to trap solar energy or heat, causing the atmosphere to warm up.
When we burn rain forests and run our cars and power plants on fossil fuels, we increase the amount of carbon dioxide in the air. Measuremnts at the Mauna Loa Observatory on the Big Island suggest we've increased carbon-dioxide concentration by roughly 20 percent in the last century. Some scientists suggest carbon dioxide levels could double over the next century. University of Hawaii solar astronomer Barry LaBonte said it is becoming increasingly clear that greenhouse gases, while they certainly play a role, make up just one of several factors in global temperature calculations. Perhaps the major factor is the sun, the biggest source of energy in the solar system.