Science academies explain global warming reality

WASHINGTON — Man-made global warming is worsening and will disrupt both the natural world and human society, warns a joint report of two of the world's leading scientific organizations.

The U.S. National Academy of Sciences and the Royal Society, which is the national scientific academy of the United Kingdom, are releasing an unusual plain language report on climate change that addressed 20 issues in a question-and-answer format.

"People do have persistent questions all about climate change," said study author Ben Santer of the Lawrence Livermore National Lab in California. "This is a one-stop shop for many of those questions."

The report, released on Thursday, addresses new issues such as the recent slowing in the increase of world temperatures and how heat-trapping gases are connected to extreme weather. Increases in extreme weather, melting glaciers, rising seas and oceans getting more acidic are already happening, the 36-page report said.

And those changes "are expected to increase greater warming and will threaten food production, freshwater supplies, coastal infrastructure and especially the welfare of the huge population currently living in low-lying areas," the report said.

The report said that while the rate of warming is slower in the 2000s than it was in the 1990s it doesn't negate the 150 years of observations that show the world is warming. The report also says that more the 90 percent of the heat trapped by greenhouse gases lately has been absorbed into the oceans' deep water, which for a while slows surface warming but not the long-term trend.

There is enough evidence on the science to warrant action, Sir Paul Nurse, president of the Royal Society, said in a news release.

"We've changed the chemical composition of the atmosphere; that's not a belief system. We know that beyond shadow of a doubt," Santer said in an interview. "We ignore this at our peril."