Report Projects 4-Foot Rise in Global Sea Level by End of Century
Nitya Venkataraman ABC News 26 Dec 08;
An Iditarod without snow, Florida's coastal towns lost forever to the Gulf of Mexico, wheat farmers in Kansas without crops.
What sounds like the climatic end of days could be coming a lot sooner than previously anticipated.
A recent report released by the U.S. Geological Survey paints abrupt climactic shifts, including a more rapid climate change with global sea level increases of up to four feet by the year 2100 and arid climatic shifts in the North American Southwest by mid-century.
Previous estimates anticipated a global sea level rise of 1.5 feet by the end of the century. The current survey, commissioned by the U.S. Climate Change Science Program, estimated that the compounding effects of the loss of Arctic Sea ice will more than double previous projections by the end of the century.
"The Arctic is a regulator of Earth's climate," Martin Sommerkorn, a senior adviser on climate change to the World Wildlife Federation, cautioned in a statement. "We are seeing troubling signs that the dramatic changes in that region threaten the rest of the planet."
The National Resources Defense Council describes the Arctic as "global warming's canary in the coal mine." Arctic ice melt, the NRDC warns, will have devastating effects beyond the polar region and well into the American heartland.
Warmer Climate Hits Alaska
The rising temperatures are already being felt across Alaska's geographic landscape. On the Kenai Peninsula, scientists believe that the warmer weather has allowed spruce bark beetles to mature and reproduce more quickly. Able to complete a two-year life cycle in only a year, the insects have eaten almost 4 million acres of forest.
In Fairbanks, a city built on top of a permafrost layer, a foundation thought to be permanently frozen, is thawing, resulting in buckling highways and sinking homes.
And the Iditarod dog sled race was forced to move its traditional starting point from Wasilla, the once-home of Alaska Gov. Sarah Palin, farther north to a location that wasn't affected by warmer temperatures and lack of snowfall.
Rising Waters to Flood Coasts
Farther south, the EPA projected that a 3-foot rise in sea level by 2100 would deluge more than 22,000 miles along the Atlantic and Gulf coasts, in regions of Louisiana, Texas, Florida and North Carolina.
In Florida, the coastal towns along the Gulf of Mexico face the reality of rising sea levels, one that could come sooner than anticipated, according to a report by the Charlotte Sun.
The town of Punta Gorda, Fla., is working with Charlotte Harbor National Estuary Program to create a model for coastal communities in the Sunshine State in the event of a worst-case scenario, mapping out shoreline changes and the inward relocation of residents and habitat.
Beyond rising sea levels, a loss of ice cover and warmer climates in the Arctic have a direct impact on weather patterns and farming.
In October, ABC News reported that Arctic sea ice had shrunk to a record low since satellite measurements began in 1979.
In 2006, the Intergovernmental Panel on Climate Change predicted an ice-free Arctic by the end of the century; the panel's prediction could now take place by the end of the decade.
"The Arctic is fundamentally changing in character, and we're going to continue this downward trend and eventually reach the point when we have entire sea-ice melts during the summertime," said Walt Meier, a research scientist at the National Snow and Ice Data Center.
His organization warned that the global consequences for a planet without sea ice were major, explaining that the Arctic region "acts as a giant air conditioner for the planet, helping stabilize global temperature and weather patterns in lower latitudes, like the jet stream."
Using a NASA computer model, the NRDC links Arctic melts to wheat farming in Kansas, projecting that without ice covers, the state would be 4 degrees warmer in the winter, which would hurt wheat farmers who rely on freezing temperatures to grow their crops. Kansas summers would face drier crop soil sapped of 10 percent of its moisture.
"These findings offer a startling view of climate change in the Arctic and the profound impact it may already be having on the future of the entire planet," said Richard Moss, vice president for WWF's Climate Change Program and previously head of the CCSP coordination office, in a statement.
Moss continued, "World governments just concluded two weeks of climate treaty negotiations in Poland with a disappointing lack of progress. As negotiations continue over the course of the coming year, this report should provide a much-needed sense of urgency to help reach agreement next December in Copenhagen.
ABC News Clayton Sandell and Angus Hines contributed to the reporting in this report.
Agencies' report warns of faster climate change
Juliet Eilperin, LA Times 26 Dec 08;
Reporting from Washington -- The United States faces the possibility of much more rapid climate change by the end of the century than previous studies have suggested, according to a report led by the U.S. Geological Survey.
The study, which was commissioned by the U.S. Climate Change Science Program and issued this month, expands on the 2007 findings of the United Nations Intergovernment Panel on Climate Change. Looking at factors such as rapid sea ice loss in the Arctic and prolonged drought in the Southwest, the new assessment suggests that earlier projections may have underestimated the climatic shifts that could take place by 2100.
However, the assessment also suggests that some other feared effects of global warming are not likely to occur by the end of the century, such as an abrupt release of methane from the seabed and permafrost or a shutdown of the Atlantic Ocean circulation system that brings warm water north and colder water south. But the report projects an amount of potential sea level rise during that period that may be greater than what other researchers have anticipated, as well as a shift to a more arid climate pattern in the Southwest by midcentury.
Thirty-two scientists from federal and nonfederal institutions contributed to the report, which took nearly two years to complete. The Climate Change Science Program, which was established in 1990, coordinates the climate research of 13 federal agencies.
Tom Armstrong, senior advisor for global change programs at the U.S. Geological Survey, said the report "shows how quickly the information is advancing" on potential climate shifts. The prospect of abrupt climate change, he said, "is one of those things that keeps people up at night, because it's a low-probability but high-risk scenario. It's unlikely to happen in our lifetimes, but if it were to occur, it would be life-changing."
In one of the report's most worrisome findings, the agency estimates that in light of recent ice sheet melting, global sea levels could rise as much as 4 feet by 2100. The intergovernment panel had projected a rise of no more than 1.5 feet by that time, but satellite data over the last two years show the world's major ice sheets are melting much more rapidly than previously thought. The Antarctic and Greenland ice sheets are losing an average of 48 cubic miles of ice a year, equivalent to twice the amount of ice in the Alps.
Konrad Steffen, who directs the Cooperative Institute for Research in Environmental Sciences at the University of Colorado at Boulder and was lead author on the report's chapter on ice sheets, said the models the intergovernment panel used did not factor in some of the dynamics that scientists now understand about ice sheet melting. Steffen and his collaborators have identified, among other things, a process of "lubrication," in which warmer ocean water gets underneath coastal ice sheets and accelerates melting.
"This has to be put into models," said Steffen, who organized a conference during the summer in St. Petersburg, Russia, as part of an effort to develop more sophisticated ice sheet models. "What we predicted is sea level rise will be higher, but I have to be honest, we cannot model it for 2100 yet."
Still, Armstrong said, the report "does take a step forward from where the [intergovernment panel] was," especially in terms of ice sheet melting.
Scientists also looked at the prospect of prolonged drought over the next 100 years. They said it was impossible to determine yet whether human activity is responsible for the drought the Southwestern United States has experienced over the last decade, but every indication suggests the region will become consistently drier in the next several decades. Richard Seager, a senior research scientist at Columbia University's Lamont-Doherty Earth Observatory, said that nearly all of the 24 computer models the group surveyed projected the same climatic conditions for the North American Southwest, which includes Mexico.
"If the models are correct, it will transition in the coming years and decades to a more arid climate, and that transition is already underway," Seager said, adding that such conditions would probably include prolonged droughts lasting more than a decade.
The current models cover broad swaths of landscape, and Seager said scientists needed to work on developing versions that can make projections on a much smaller scale.
Armstrong said the need for "downscaled models" was one of the challenges facing the federal government. When it comes to abrupt climate shifts, he said, "we need to be prepared to deal with it in terms of policymaking. . . . There are really no policies in place to deal with abrupt climate change."
Richard Moss, who worked for the Climate Change Science Program from 2000 to 2006 and now serves as vice president and managing director for climate change at the World Wildlife Fund-U.S., welcomed the report but called it "way overdue."
"There is finally a greater flow of climate science from the administration," Moss said, noting that the report was originally scheduled to come out in 2007. "It really is showing the potential for abrupt climate change is real."
The report is reassuring, however, on the prospects for some potentially drastic effects, such as a huge release of methane, a potent heat-trapping gas, that is now locked deep in the seabed and underneath the Arctic permafrost. That is unlikely to occur in the near future, the scientists said.
"It's unlikely that we're going to see an abrupt change in methane over the next hundred years, but we should worry about it over a longer time frame," said Ed Brook, the lead author of the methane chapter and a geosciences professor at Oregon State University. "All of these places where methane is stored are vulnerable to leaking."
By the end the century, Brook said, the amount of methane escaping from natural sources such as the Arctic tundra and waterlogged soils in warmer regions "could possibly double," but that would still be less than the current level of human-generated methane emissions. Over the course of the next thousand years, he added, methane hydrates stored deep in the seabed could be released.
"Once you start melting there, you can't really take it back," he said.
Eilperin writes for the Washington Post.
