Global warming will continue for the next hundred years even if the use of fossil fuels is dramatically reduced, leading scientists said today.
Climate models indicate temperature increases of three to more than 10 degrees Fahrenheit this century and a rise in sea levels of six inches to nearly three feet.
Experts attending America's biggest science meeting today were told so much greenhouse gas was in the atmosphere already that nothing could stop the world heating up over the next 100 years.
Professor Robert Dickinson, from the Georgia Institute of Technology in Atlanta said: "The effects of carbon dioxide (CO2) that has been released into the atmosphere from the burning of fossil fuels last for at least 100 years.
That means that any reductions in CO2 that are expected to be possible over this period will not result in a cleaner atmosphere and less global warming than we see today for at least a century."
He told the American Association for the Advancement of Science meeting in Boston, Massachusetts, that significant consequences from global warming were inevitable over the next 100 years.
"Given enough time, there may be as many winners as losers," he said.
"However, many of the losers will be very unhappy, such as people who live on islands that will be put under water. It will take a lot of time for humans to adjust their systems to these changes. The biggest problem is the speed at which global warming is occurring."
He said it was possible man-made warming was amplifying patterns of natural variability.
The only way to stop the amount of carbon dioxide in the atmosphere increasing was to reduce emissions of the greenhouse gas by up to 20 to 30% of today's levels. That would require reductions in motor vehicle emissions and the amount of carbon dioxide produced by coal-fired power stations.
"We have to move our energy systems to forms other than fossil fuels," said Prof Dickinson. "And when I say we, I don't just mean the United States. The US is the biggest user of fossil fuels, but China and India are likely to surpass the US in the next 50 years, and China may surpass the US in the next decade."
PA