American Shores Face Threat of Rising Sea Level

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.

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"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.