----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, August 29, 2000 7:50 AM Subject: [hydroinformatics-asia-pacific] Cimate Change > -------------------------- eGroups Sponsor -------------------------~-~> > Free @Backup service! Click here for your free trial of @Backup. > @Backup is the most convenient way to securely protect and access > your files online. Try it now and receive 300 MyPoints. > http://click.egroups.com/1/6348/10/_/43293/_/968241182/ > ---------------------------------------------------------------------_-> > > NEWS FROM THE WORLDWATCH INSTITUTE > > > From the Office of the Chairman > > Worldwatch Issue Alert > > Alert 2000 - 7 > > Embargoed for Release > > August 29, 2000 > > 6 PM > > > > > CLIMATE CHANGE HAS WORLD SKATING ON THIN ICE > > > Lester R. Brown > > > If any explorers had been hiking to the North Pole this summer, they would > > have had to swim the last few miles. The discovery of open water at the Pole > by > > an ice-breaker cruise ship in mid August surprised many in the scientific > > community. > > This finding, combined with two recent studies, provides not only more > > evidence that the Earth's ice cover is melting, but that it is melting at an > > accelerating rate. A study by two Norwegian scientists projects that within 50 > > years, the Arctic Ocean could be ice-free during the summer. The other, a > study > > by a team of four U.S. scientists, reports that the vast Greenland ice sheet > is > > melting. > > The projection that the Arctic Ocean will lose all its summer ice is not > > surprising, since an earlier study reported that the thickness of the ice > sheet > > has been reduced by 42 percent over the last four decades. The area of the ice > > sheet has also shrunk by 6 percent. Together this thinning and shrinkage have > > reduced the Arctic Ocean ice mass by nearly half. > > Meanwhile, Greenland is gaining some ice in the higher altitudes, but it > is > > losing much more at lower elevations, particularly along its southern and > > eastern coasts. The huge island of 2.2 million square kilometers (three times > > the size of Texas) is experiencing a net loss of some 51 billion cubic meters > of > > water each year, an amount equal to the annual flow of the Nile River. > > The Antarctic is also losing ice. In contrast to the North Pole, which is > > covered by the Arctic Sea, the South Pole is covered by the Antarctic > continent, > > a land mass roughly the size of the United States. Its continent-sized ice > > sheet, which is on average 2.3 kilometers (1.5 miles) thick, is relatively > > stable. But the ice shelves, the portions of the ice sheet that extend into > the > > surrounding seas, are fast disappearing. > > A team of U.S. and British scientists reported in 1999 that the ice > shelves > > on either side of the Antarctic Peninsula are in full retreat. From roughly > > mid-century through 1997, these areas lost 7,000 square kilometers as the ice > > sheet disintegrated. But then within scarcely a year they lost another 3,000 > > square kilometers. Delaware-sized icebergs that have broken off are > threatening > > ships in the area. The scientists attribute the accelerated ice melting to a > > regional temperature rise of some 2.5 degrees Celsius (4.5 degrees Fahrenheit) > > since 1940. > > These are not the only examples of melting. My colleague, Lisa Mastny, who > > has reviewed some 30 studies on this topic, reports that ice is melting almost > > everywhere--and at an accelerating rate. (See Worldwatch News Brief, March 6, > > 2000 http://www.worldwatch.org/alerts/000306.html ) The snow/ice mass is > > shrinking in the world's major mountain ranges: the Rocky Mountains, the > Andes, > > the Alps, and the Himalayas. In Glacier National Park in Montana, the number > of > > glaciers has dwindled from 150 in 1850 to fewer than 50 today. The U.S. > > Geological Survey projects that the remaining glaciers will disappear within > 30 > > years. > > Scientists studying the Quelccaya glacier in the Peruvian Andes report > that > > its retreat has accelerated from 3 meters a year between roughly 1970 and 1990 > > to 30 meters a year since 1990. In Europe's Alps, the shrinkage of the glacial > > area by 35-40 percent since 1850 is expected to continue. These ancient > glaciers > > could largely disappear over the next half-century. > > Shrinkage of ice masses in the Himalayas has accelerated alarmingly. In > > eastern India, the Dokriani Bamak glacier, which retreated by 16 meters > between > > 1992 and 1997, drew back by a further 20 meters in 1998 alone. > > This melting and shrinkage of snow/ice masses should not come as a total > > surprise. Swedish scientist Svente Arrhenius warned at the beginning of the > last > > century that burning fossil fuels could raise atmospheric levels of carbon > > dioxide (CO2), creating a greenhouse effect. Atmospheric CO2 levels, estimated > > at 280 parts per million (ppm) before the Industrial Revolution, have climbed > > from 317 ppm in 1960 to 368 ppm in 1999--a gain of 16 percent in only four > > decades. > > As CO2 concentrations have risen, so too has Earth's temperature. Between > > 1975 and 1999, the average temperature increased from 13.94 degrees Celsius to > > 14.35 degrees, a gain of 0.41 degrees or 0.74 degrees Fahrenheit in 24 years. > > The warmest 23 years since recordkeeping began in 1866 have all occurred since > > 1975. > > Researchers are discovering that a modest rise in temperature of only 1 > or 2 > > degrees Celsius in mountainous regions can dramatically increase the share of > > precipitation falling as rain while decreasing the share coming down as snow. > > The result is more flooding during the rainy season, a shrinking snow/ice > mass, > > and less snowmelt to feed rivers during the dry season. > > These "reservoirs in the sky," where nature stores fresh water for use in > > the summer as the snow melts, are shrinking and some could disappear entirely. > > This will affect the water supply for cities and for irrigation in areas > > dependent on snowmelt to feed rivers. > > If the massive snow/ice mass in the Himalayas--which is the third largest > in > > the world, after the Greenlandic and Antarctic ice sheets--continues to melt, > it > > will affect the water supply of much of Asia. All of the region's major > > rivers--the Indus, Ganges, Mekong, Yangtze, and Yellow--originate in the > > Himalayas. The melting in the Himalayas could alter the hydrology of several > > Asian countries, including Pakistan, India, Bangladesh, Thailand, Viet Nam, > and > > China. Less snowmelt in the summer dry season to feed rivers could exacerbate > > the hydrological poverty already affecting so many in the region. (See Issue > > Alerts 1 and 4 www.worldwatch.org/alerts/indexia.html ) > > As the ice on land melts and flows to the sea, sea level rises. Over the > > last century, sea level rose by 20-30 centimeters (8-12 inches). During this > > century, the existing climate models indicate it could rise by as much as 1 > > meter. If the Greenland ice sheet, which is up to 3.2 kilometers thick in > > places, were to melt entirely, sea level would rise by 7 meters (23 feet). > > Even a much more modest rise would affect the low-lying river floodplains > of > > Asia, where much of the region's rice is produced. According to a World Bank > > analysis, a 1-meter rise in sea level would cost low-lying Bangladesh half its > > riceland. Numerous low-lying island countries would have to be evacuated. The > > residents of densely populated river valleys of Asia would be forced inland > into > > already crowded interiors. Rising sea level could create climate refugees by > the > > million in countries such as China, India, Bangladesh, Indonesia, Viet Nam, > and > > the Philippines. > > Even more disturbing, ice melting itself can accelerate temperature rise. > As > > snow/ice masses shrink, less sunlight is reflected back into space. With more > > sunlight absorbed by less reflective surfaces, temperature rises even faster > and > > melting accelerates. > > We don't have to sit idly by as this scenario unfolds. There may still be > > time to stabilize atmospheric CO2 levels before continuing carbon emissions > > cause climate change to spiral out of control. We have more than enough wind, > > solar, and geothermal energy that can be economically harnessed to power the > > world economy. If we were to incorporate the cost of climate disruption in the > > price of fossil fuels in the form of a carbon tax, investment would quickly > > shift from fossil fuels to these climate-benign energy sources. > > The leading automobile companies are all working on fuel cell engines. > > Daimler Chrysler plans to start marketing such an automobile in 2003. The fuel > > of choice for these engines is hydrogen. Even leaders within the oil industry > > recognize that we will eventually shift from a carbon-based energy economy to > a > > hydrogen-based one. The question is whether we can make that shift before > > Earth's climate system is irrevocably altered. > > > - end - > > > FOR DATA, GRAPHS, AND ADDITIONAL INFORMATION > > WWW.WORLDWATCH.ORG/ALERTS/INDEXIA.HTML > > If you know someone who might like to receive the Issue Alerts regularly, > please > > contact Reah Janise Kauffman [EMAIL PROTECTED] . > > > COPYRIGHT: 2000 Worldwatch Institute > > CONTACT: Reah Janise Kauffman > > PHONE: (202) 452-1992 x 514 > > FAX: (202) 296-7365 > > > >
