Robert Taylor Human Effect on global warming

WASHINGTON -- Now that most scientists agree that human activity is causing earth to warm, the central debate has shifted to whether climate change is progressing so rapidly that, within decades, humans may be helpless to slow or reverse the trend.

This ''tipping point" question has begun to consume many prominent researchers in the United States and abroad, because the answer could determine how drastically countries need to reduce their greenhouse gas emissions in the coming years.

Earth's average temperature has risen nearly 1 degree Fahrenheit over the past 30 years, Hansen noted, and another increase of about 4 degrees over the next century would ''imply changes that constitute practically a different planet."

external image global-warming-big-cause-image.jpg

''It's not something you can adapt to," Hansen said in an interview. ''We can't let it go on another 10 years like this. We've got to do something."

Princeton University geosciences and international affairs professor Michael Oppenheimer, who also advises the advocacy group Environmental Defense, said one of the greatest dangers lies in the disintegration of the Greenland or West Antarctic ice sheets, which together hold about 20 percent of the fresh water on the planet.
ohn Christy, the director of the Earth Science System Center at the University of Alabama in Huntsville, said that increased warming could possibly be offset by other factors, such as increased cloudiness that would reflect more sunlight. ''Whatever happens, we will adapt to it," Christy said.

Scientists who read the history of earth's climate in ancient sediments, ice cores, and fossils find clear signs that it has shifted abruptly in the past on a scale that could prove disastrous for modern society.
Some scientists, including President Bush's chief science adviser, John Marburger III, emphasize that much uncertainty remains about when abrupt global warming might occur.

We offer simple solutions to today's most pressing environmental issue, climate change. Knowing a busy lifestyle is as American as apple pie, we've created straight forward actions that enable us all to make a difference, one step at a time.

As a result, the land temperature in Greenland dropped more than 9 degrees Fahrenheit within one or two decades

That indicates that scientists may have underestimated the rate of disintegration they face in the future, Oppenheimer said. Greenland's current net ice loss is equivalent to an annual 0.008 inch sea level rise.

Last year the British government sponsored a scientific symposium on ''Avoiding Dangerous Climate Change," which examined a number of possible tipping points.

The Basics of Global Warming
The Basics of Global Warming
heat is taping gasses at the ozon