updated 8:41 p.m. ET, Thurs., Sept . 24, 2009
WASHINGTON - Earth's temperature is likely to jump six degrees between now and the end of the century even if every country cuts greenhouse gas emissions as proposed, according to a United Nations update.
Scientists looked at emission plans from 192 nations and calculated what would happen to global warming. The projections take into account 80 percent emission cuts from the U.S. and Europe by 2050, which are not sure things.
The U.S. figure is based on a bill that passed the House of Representatives but is running into resistance in the Senate, where debate has been delayed by health care reform efforts.
Carbon dioxide, mostly from the burning of fossil fuels such as coal and oil, is the main cause of global warming, trapping the sun's energy in the atmosphere. The world's average temperature has already risen 1.4 degrees since the 19th century.
Even if the developed world cuts its emissions by 80 percent and the developing world cuts theirs in half by 2050, as some experts propose, the world is still facing a 3-degree increase by the end of the century, said Robert Corell, a prominent U.S. climate scientist who helped oversee the update.
Global warming is speeding up, especially in the Arctic, and that means that some top-level science projections from 2007 are already out of date and overly optimistic. Corell, who headed an assessment of warming in the Arctic, said global warming "is accelerating in ways that we are not anticipating."
Because Greenland and West Antarctic ice sheets are melting far faster than thought, it looks like the seas will rise twice as fast as projected just three years ago, Corell said. He said seas should rise about a foot every 20 to 25 years.
Other problems that have worsened since the 2007 report include the oceans getting more acidic — a threat to some sea creatures — and projections for regular long-term droughts in the U.S. Southwest.
"As sobering as this report is, it is not the worst case scenario," said U.S. Rep. Edward Markey, co-author of the bill that passed the U.S. House. "That would be if the world does nothing and allows heat-trapping pollution to continue to spew unchecked into the atmosphere."
I wonder if this takes into account the melting of the methane hydrates in the ocean depths, which appears to have already started?