Scientists Sound Warning on Global Warming

Dec. 15, 2005 -- -- NASA has just announced that for the fourth year in a row, it has recorded the hottest annual global temperatures since reliable records started in the late 1800s.

This year, 2005, tied for the hottest year ever with 1998 -- and 1998 was "an El Niño of the Century year -- and El Niños always make it hotter. If this had been an El Niño year, it would surely have been the hottest year of all," Dr. James Hansen, NASA earth sciences director, told ABC News.

As is well-known by now, NASA reported at summer's end that, over the last 30 years, the Arctic's summer sea ice cover had melted back 30 percent. As a number of scientists have calculated, it could be completely gone long before the end of the century.

That's why three environmental groups have filed suit against the U.S. government to get the polar bear listed as an endangered species.

Drowning Polar Bears

The polar bear's Latin name is Ursus maritimus -- which means "sea bear" -- because it is almost entirely dependent on the sea ice for its food. It spends almost all its time roaming the frozen sea surface hunting its favorite sustenance -- the seal -- and training its cubs to do the same. On land, polar bears are clumsy hunters so their existence is threatened as the Arctic keeps melting. Already, field researchers have reported disruptions in the polar bears' well-being -- a growing number of females now failing to gain enough weight during the summer to be able to breed.

A survey by the U.S. Mineral Management Service has recorded elevated numbers of polar bears drowning. Some have been found swimming far out in the warming Arctic sea as the sea ice pulls back farther from land and the bears try to swim to shore.

The three environmental groups are hoping their suit for endangered species status will force the Bush administration to face the issue of global warming.

Global Warming's Extinction Threat

No natural climate cycles can explain the heat. It must be caused, in large measure at least, by manmade greenhouse-gas emissions, NASA scientists said.

As for humans, new studies in the journal Nature have confirmed the World Health Organization estimates that, conservatively, 150,000 more people die each year -- and five million more get sick -- because manmade global warming is helping insect- and water-borne diseases to spread, especially among poorer nations.

Scientists in the tropics have reported that warming is drying forests, spurring a growing number of extinctions, and threatening even the many species of wild orchids that rely on near-constant mist in the cloud forests.

"If it gets any warmer, I don't see how extinction can be avoided," said Karen Masters, an American scientist working on wild orchids in Costa Rica's Monte Verde Cloud Forest.

Desperate Search for Cooler Ground

Scientists in the Arctic have been racing to catalog hundreds of species that live under the frozen sea surface.

Dr. Katrin Iken, a marine biologist from the University of Alaska who scuba dives under the Arctic ice looking for new life forms, said the warming "will definitely create a huge change in the ecosystem here in the Arctic. It makes me very sad, actually."

Around the planet, hundreds of scientists report ecosystems scattering as species try to reach cooler ground. Harvard's E.O. Wilson, who has been gauging the human impact on Earth's species for more than half a century, asks: "Do we want to destroy the Creation? That's the question. That's what we're doing, and at an accelerating rate."

At this winter's worldwide global-warming conference in Montreal, the U.S. came under a great deal of criticism from almost all the other countries for refusing to participate in any formal discussions about how to try to cut greenhouse emissions, and how to try to slow the warming that has already started to disrupt so much life around the world.