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  Yahoo News 26 Sep 06
Global temperature highest in millennia

PlanetArk 25 Sep 06
Earth may be at warmest point in 1 million years
By Deborah Zabarenko, Environment Correspondent

WASHINGTON (Reuters) - Earth may be close to the warmest it has been in the last million years, especially in the part of the Pacific Ocean where potentially violent El Nino weather patterns are born, climate scientists reported on Monday.

This doesn't necessarily mean there will be more frequent El Ninos -- which can disrupt normal weather around the world -- but could well mean that these wild patterns will be stronger when they occur, said James Hansen of NASA's Goddard Institute for Space Studies in New York City.

The El Nino phenomenon is an important factor in monitoring global warming, according to a paper by Hansen and colleagues published in the current Proceedings of the National Academy of Sciences.

El Ninos can push temperatures higher than they might ordinarily be. This happened in 1998 when a so-called "super El Nino" helped heat the Earth to a record high. What is significant, the scientists wrote, is that 2005 was in the same temperature range as 1998, and probably was the warmest year ever, with no sign of the warm surface water in the eastern equatorial Pacific typical of an El Nino.

The waters of the western equatorial Pacific are warmer than in the eastern equatorial Pacific, and the difference in temperature between these two areas could produce greater temperature swings between the normal weather pattern and El Nino, they wrote.

They blamed this phenomenon on global warming that is affecting the surface of the western Pacific before it affects the deeper water.

EL NINO AND GLOBAL WARMING

Overall, Earth is within 1.8 degrees F (1 degree C) of its highest temperature levels in the past million years, Hansen and the others wrote.

They noted a recent steep rise in average temperatures, with global surface temperatures increasing about 0.4 degrees F (0 .2 degrees C) for each of the last three decades.

Scientists attribute this rise to human activities, notably the release into the atmosphere of greenhouse gases -- notably carbon dioxide -- which let in sunlight and trap its heat like the glass walls of a greenhouse.

Human-caused global warming influences El Ninos much as it sways tropical storms, the scientists wrote. "The effect on frequency of either phenomenon is unclear, depending on many factors, but the intensity of the most powerful events is likely to increase as greenhouse gases increase," they wrote. "Slowing the growth rate of greenhouse gases should diminish the probability of both super El Ninos and the most intense tropical storms."

Weak El Nino conditions were present this month in the tropical Pacific, and could strengthen to a moderate event by winter, according to the U.S. National Oceanic and Atmospheric Administration, which monitors the phenomenon.

In the United States, private forecaster WSI Corp. predicted warmer-than-normal weather over the Northeast and Midwest for the rest of this year, spelling sluggish energy demand for the start of the heating season.

The warm outlook, after the mildest winter on record last year, is due to uncertainty over the El Nino -- a warming of Pacific waters around the equator that can drive weather patterns around the globe, WSI Corp. said.

(Additional reporting by New York Energy Desk)

Yahoo News 26 Sep 06
Global temperature highest in millennia

WASHINGTON - The planet's temperature has climbed to levels not seen in thousands of years, warming that has begun to affect plants and animals, researchers report in Tuesday's issue of Proceedings of the National Academy of Sciences.

The Earth has been warming at a rate of 0.36 degree Fahrenheit per decade for the last 30 years, according to the research team led by James Hansen of NASA's Goddard Institute for Space Studies in New York.

That brings the overall temperature to the warmest in the current interglacial period, which began about 12,000 years ago.

The researchers noted that a report in the journal Nature found that 1,700 plant, animal and insect species moved poleward at an average rate of about 4 miles per decade in the last half of the 20th century.

The warming has been stronger in the far north, where melting ice and snow expose darker land and rocks beneath allowing more warmth from the sun to be absorbed, and more over land than water.

Water changes temperature more slowly than land because of its great capacity to hold heat, but the researchers noted that the warming has been marked in the Indian and western Pacific Oceans.

Those oceans have a major effect on climate and warming that could lead to more El Nino episodes affecting the weather.

"This evidence implies that we are getting close to dangerous levels of human-made pollution," Hansen said in a statement.

Few scientists doubt that the planet has warmed, though some question the causes of the change.

Hansen, who first warned of the danger of climate change decades ago, said that human- made greenhouse gases have become the dominant climate change factor.

The study said the recent warming has brought global temperature to a level within about one degree Celsius — 1.8 degree Fahrenheit — of the maximum temperature of the past million years.

"If further global warming reaches 2 or 3 degrees Celsius, we will likely see changes that make Earth a different planet than the one we know. The last time it was that warm was in the middle Pliocene, about 3 million years ago, when sea level was estimated to have been about 25 meters (80 feet) higher than today," Hansen said.
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