Warming is well under way, say scientists

From the micro to the macro, from plankton in the oceans to polar bears in the far north and seals in the far south, global warming has begun changing life on Earth, international scientists will report next Friday.

"Changes in climate are now affecting physical and biological systems on every continent," says a draft obtained by The Associated Press of a report on warming's impacts, to be issued by the Intergovernmental Panel on Climate Change (IPCC), the authoritative U.N. network of 2,000 scientists and more than 100 governments.

In February the panel declared it "very likely" most global warming has been caused by manmade emissions of carbon dioxide and other greenhouse gases.

Animal and plant life in the Arctic and Antarctic is undergoing substantial change, scientists say. Rising sea levels elsewhere are damaging coastal wetlands. Warmer waters are bleaching and killing coral reefs, pushing marine species toward the poles, reducing fish populations in African lakes, research finds.

"Hundreds of species have already changed their ranges, and ecosystems are being disrupted," said University of Michigan ecologist Rosina Bierbaum, former head of the U.S. IPCC delegation. "It is clear that a number of species are going to be lost."

The IPCC draft estimates that if temperatures rise approximately 2 to 4 degrees Fahrenheit more, one-third of species will be lost from their current range, either moved elsewhere or vanished.

From Associated Press bureaus around the world, here are snapshots of animals and plants the IPCC will identify as already affected by climate change:

Puerto Rico

Back in the Puerto Rican rain forest for the first time in five years, biologist Rafael Joglar sensed something was wrong. He wasn't hearing the frogs whose nocturnal calls he had long recorded in the misty highlands.

It was as if a small orchestra had lost key players, he recalled.

After that discovery in 1981, Joglar and wife Patricia Burrowes, a fellow University of Puerto Rico amphibian specialist, found that other populations of frogs in the genus Eleutherodactylus — known locally as coquis for the distinctive co-kee sound made by two species — were also mysteriously absent. Similar reports trickled in from frog specialists worldwide, particularly in Central and South America.

Working their way through such suspected culprits as pollution and habitat loss, researchers here eventually zeroed in on climate change. The average minimum temperature had risen from 1970 to 2000 by 2 degrees Fahrenheit, a significant rise for climate-sensitive amphibians.