by Julie Steenhuysen

CHICAGO  - The climate is heating up far faster than scientists had predicted, spurred by sharp increases in greenhouse gas emissions from developing countries like China and India, a top climate scientist said on Saturday.

"The consequence of that is we are basically looking now at a future climate that is beyond anything that we've considered seriously," Chris Field, a member of the Intergovernmental Panel on Climate Change, or IPCC, told the American Association for the Advancement of Science meeting in Chicago.

Field said "the actual trajectory of climate change is more serious" than any of the climate predictions in the IPCC's fourth assessment report called "Climate Change 2007."

He said recent climate studies suggested the continued warming of the planet from greenhouse gas emissions could touch off large, destructive wildfires in tropical rain forests and melt permafrost in the Arctic tundra, releasing billions of tons of greenhouse gasses that could raise global temperatures even more.

"There is a real risk that human-caused climate change will accelerate the release of carbon dioxide from forest and tundra ecosystems, which have been storing a lot of carbon for thousands of years," Field, of Stanford University and the Carnegie Institution for Science, said in a statement.

He pointed to recent studies showing the fourth assessment report underestimated the potential severity of global warming over the next 100 years.

"We now have data showing that from 2000 to 2007, greenhouse gas emissions increased far more rapidly than we expected, primarily because developing countries, like China and India, saw a huge surge in electric power generation, almost all of it based on coal," Field said.

He said that trend was likely to continue if more countries turned to coal and other carbon-intensive fuels to meet their energy needs. If so, he said the impact of climate change would be "more serious and diverse" than the IPCC's most recent predictions.

Editing by Peter Cooney