2. What is Global Warming?

2005

17 February 2005. Scripps Researchers Find Clear Evidence of Human-Produced Warming in World's Oceans. Scripps News release. Excerpt:Scientists at Scripps Institution of Oceanography at the University of California, San Diego, and their colleagues have produced the first clear evidence of human-produced warming in the world's oceans, a finding they say removes much of the uncertainty associated with debates about global warming.
In a new study conducted with colleagues at Lawrence Livermore National Laboratory's Program for Climate Model Diagnosis and Intercomparison (PCMDI),Tim Barnett and David Pierce of Scripps Institution used a combination of computer models and real-world "observed" data to capture signals of the penetration of greenhouse gas-influenced warming in the oceans. The authors make the case that their results clearly indicate that the warming is produced anthropogenically, or by human activities.
"This is perhaps the most compelling evidence yet that global warming is happening right now and it shows that we can successfully simulate its past and likely future evolution," said Tim Barnett, a research marine physicist in the Climate Research Division at Scripps. Barnett says he was "stunned" by the results because the computer models reproduced the penetration of the warming signal in all the oceans. "The statistical significance of these results is far too strong to be merely dismissed and should wipe out much of the uncertainty about the reality of global warming."
...In the new study, Barnett and his colleagues used computer models of climate to calculate human-produced warming over the last 40 years in the world's oceans. In all of the ocean basins, the warming signal found in the upper 700 meters predicted by the models corresponded to the measurements obtained at sea with confidence exceeding 95 percent. The correspondence was especially strong in the upper 500 meters of the water column....

25 January 2005. Antarctica, Warming, Looks Ever More Vulnerable. By Larry Rohter. OVER THE ABBOTT ICE SHELF, Antarctica - From an airplane at 500 feet, all that is visible here is a vast white emptiness. Ahead, a chalky plain stretches as far as the eye can see, the monotony broken only by a few gentle rises and the wrinkles created when new sheets of ice form. Under the surface of that ice, though, profound and potentially troubling changes are taking place, and at a quickened pace. With temperatures climbing in parts of Antarctica in recent years, melt water seems to be penetrating deeper and deeper into ice crevices, weakening immense and seemingly impregnable formations that have developed over thousands of years. As a result, huge glaciers in this and other remote areas of Antarctica are thinning and ice shelves the size of American states are either disintegrating or retreating - all possible indications of global warming. Scientists from the British Antarctic Survey reported in December that in some parts of the Antarctic Peninsula hundreds of miles from here, large growths of grass are appearing in places that until recently were hidden under a frozen cloak.... Glaciologists also know that by itself, free-floating sea ice does not raise the level of the sea, just as an ice cube in a glass of water does not cause an overflow as it melts. But glaciers are different because they rest on land, and if that vast volume of ice slides into the sea at a high rate, this adds mass to the ocean, which in turn can raise the global sea level.... In 1995 ... the Larsen A ice shelf disintegrated, followed in 1998 by the collapse of the nearby Wilkins ice shelf. Over a 35-day period early in 2002, at the end of the Southern Hemisphere summer, the Larsen B ice shelf shattered, losing more than a quarter of its total mass and setting thousands of icebergs adrift in the Weddell Sea.

2004

21 September 2004. NASA RELEASE : 04-302 Glaciers Surge When Ice Shelf Breaks Up. Since 2002, when the Larsen B ice shelf broke away from the coast of the Antarctic Peninsula, scientists have witnessed profound increases in the flow of nearby glaciers into the Weddell Sea. These observations were made possible through NASA, Canadian and European satellite data.

August 2004. Satellite-Observed Changes in the Arctic. Physics Today, Volume 57, Number 8. Josefino C. Comiso and Claire L. Parkinson. The Arctic has warmed by about 1°C in the past two decades. That time period has seen glaciers retreat, permafrost thaw, snow cover decrease, and ice sheets thin -

8 June 2004. NY Times: A Big Melt. By HENRY FOUNTAIN. If global warming has the potential for making over the planet, then what happened at the dawn of the Eocene epoch 55 million years ago may best be described as an extreme makeover. That is when a rapid influx of carbon dioxide into the atmosphere caused average temperatures to increase by close to 15 degrees Fahrenheit over 200,000 years.

2003

23 October 2003. Recent Warming Of Arctic May Affect Worldwide Climate, NASA RELEASE: 03-340. Recently observed change in Arctic temperatures and sea ice cover may be a harbinger of global climate changes to come, according to a recent NASA study.... The Arctic warming study, appearing in the November 1 issue of the American Meteorological Society's Journal of Climate, shows that compared to the 1980s, most of the Arctic warmed significantly over the last decade, with the biggest temperature increases occurring over North America.... Researchers have suspected loss of Arctic sea ice may be caused by changing atmospheric pressure patterns over the Arctic that move sea ice around, and by warming Arctic temperatures that result from greenhouse gas buildup in the atmosphere.... According to Comiso's study, when compared to longer term ground-based surface temperature data, the rate of warming in the Arctic over the last 20 years is eight times the rate of warming over the last 100 years. .... The surface temperature records covering from 1981 to 2001 were obtained through thermal infrared data from National Oceanic and Atmospheric Administration satellites.

2002

6 December 2002. Climate change may be cause of Earth's equatorial bulge. NASA Research Offers Explanation for Earth's Bulging Waistline . A team of researchers from NASA's Jet Propulsion Laboratory, Pasadena, Calif., and the Royal Observatory of Belgium has apparently solved a recently observed mystery regarding changes to the physical shape of Earth and its gravity field. The answer, they found, appears to lie in the melting of sub-polar glaciers and mass shifts in the Southern, Pacific and Indian Oceans associated with global-scale climate changes.

17 September 2002. NASA SCIENTISTS USE SATELLITES TO DISTINGUISH HUMAN POLLUTION FROM OTHER ATMOSPHERIC PARTICLES. Excerpt: Driven by precise new satellite measurements and sophisticated new computer models, a team of NASA researchers is now routinely producing the first global maps of fine aerosols that distinguish plumes of human-produced particulate pollution from natural aerosols...

2 August 2002. Earth's girth grows -- (www.nature.com) Our planet's waistline is mysteriously increasing. by TOM CLARKE. © NASA. After 18,000 years of slimming, our planet has suddenly turned tubby round the middle. Researchers are baffled by the bulge. ... accurate measurements of satellite orbits, made using lasers in the 1980s, revealed that the Earth was, in fact, becoming gradually more spherical. As the ice caps melted after the most recent ice age, their weight was removed from the poles - the poles were rising back to their original position after millennia under pressure. At least, they were until 1998. For the past four years the slimming has reversed, say Christopher Cox at Raytheon, a research and technology company in Lanham, Maryland, and Benjamin Chao at NASA's Goddard Space Flight Center in Greenbelt, also in Maryland.

2001

5 November 2001. SATELLITES SHED LIGHT ON A WARMER WORLD. While winter may be approaching, researchers using data from satellites and weather stations around the world have found the air temperature near the Earth's surface has warmed on average by 1 degree F (0.6 degree C) globally over the last century, and they cite human influence as at least a partial cause. Dr. James Hansen of NASA's Goddard Institute for Space Studies, New York, and Marc Imhoff of NASA's Goddard Space Flight Center, Greenbelt, Md., along with several other researchers analyzed records for 7,200 global weather stations and used satellite observations of nighttime lights around the planet to identify stations with minimal local human influence. Their findings appeared in a recent issue of the Journal of Geophysical Research-Atmospheres.

23 April 2001 -- GREENHOUSE GASES CAUSE NORTHERN WINTER WARMING. Greenhouse gases are the main reason why the Northern Hemisphere is warming quicker during wintertime months than the rest of the world. New climate model results published by NASA scientists in the April 16th issue of the Journal of Geophysical Research show that greenhouse gases increase the strength of the polar winds that regulate northern hemisphere climate in winter.

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