Global Warming Poses Threat to New York City
(PhysOrg.com) -- Global warming is expected to cause the sea level along the northeastern U.S. coast to rise almost twice as fast as global sea levels during this century, putting New York City at greater risk for damage from hurricanes and winter storm surge, according to a new study led by a Florida State University researcher.
Jianjun Yin, a climate modeler at the Center for Ocean-Atmospheric Prediction Studies (COAPS) at Florida State, said there is a better than 90 percent chance that the sea level rise along this heavily populated coast will exceed the mean global sea level rise by the year 2100. The rising waters in this region -- perhaps by as much as 18 inches or more -- can be attributed to thermal expansion and the slowing of the North Atlantic Ocean circulation because of warmer ocean surface temperatures.
Yin and colleagues Michael Schlesinger of the University of Illinois at Urbana-Champaign and Ronald Stouffer of Geophysical Fluid Dynamics Laboratory at Princeton University are the first to reach that conclusion after analyzing data from 10 state-of-the-art climate models, which have been used for the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report. Yin’s study, “Model Projections of Rapid Sea Level Rise on the Northeast Coast of the United States,” will be published online March 15 in the journal Nature Geoscience.
“The northeast coast of the United States is among the most vulnerable regions to future changes in sea level and ocean circulation, especially when considering its population density and the potential socioeconomic consequences of such changes,” Yin said. “The most populous states and cities of the United States and centers of economy, politics, culture and education are located along that coast.”
The researchers found that the rapid sea-level rise occurred in all climate models whether they depicted low, medium or high rates of greenhouse-gas emissions. In a
medium greenhouse-gas emission scenario, the New York City coastal area would see an additional rise of about 8.3 inches above the mean sea level rise that is expected around the globe because of human-induced climate change.
Thermal expansion and the melting of land ice, such as the Greenland ice sheet, are expected to cause the global sea-level rise. The researchers projected the global sea-level rise of 10.2 inches based on thermal expansion alone. The contribution from the land ice melting was not assessed in this study due to uncertainty.
Considering that much of the metropolitan region of New York City is less than 16 feet above the mean sea level, with some parts of lower Manhattan only about 5 feet above the mean sea level, a rise of 8.3 inches in addition to the global mean rise would pose a threat to this region, especially if a hurricane or winter storm surge occurs, Yin said.
Potential flooding is just one example of coastal hazards associated with sea-level rise, Yin said, but there are other concerns as well. The submersion of low-lying land, erosion of beaches, conversion of wetlands to open water and increase in the salinity of estuaries all can affect ecosystems and damage existing coastal development.
Although low-lying Florida and Western Europe are often considered the most vulnerable to sea level changes, the northeast U.S. coast is particularly vulnerable because the Atlantic meridional overturning circulation (AMOC) is susceptible to global warming. The AMOC is the giant circulation in the Atlantic with warm and salty seawater flowing northward in the upper ocean and cold seawater flowing southward at depth. Global warming could cause an ocean surface warming and freshening in the high-latitude North Atlantic, preventing the sinking of the surface water, which would slow the AMOC.
Provided by Florida State University
The Collapse of the Wilkins Ice Shelf
On April 3rd, 2009, scientists from the European Space Agency announced that the Wilkins Ice Shelf, a mass of Antarctic ice, larger in area than Connecticut, was in “imminent” danger of breaking up. New rifts had appeared and a large ice block had broken away earlier in the week. The announcement did not come as a surprise. The ice shelf had been stable for most of the last century but began retreating in the 1990s. In 2008, the Wilkins Ice Shelf experienced three breakups leaving only a thin, 6-kilometer-wide ice bridge as the only thing connecting the northern front of the Wilkins Ice Shelf and the ice surrounding Charcot and Latady islands. The bridge was acting as a barrier or dam, holding back icebergs from previous collapses from as early as 1998 from entering the Southern Ocean and keeping in place the remnant shelf structure. In January of 2009, David Vaughan of the British Antarctic Survey and colleagues from the Netherlands placed a GPS unit on the bridge between Charcot and Latady islands. (See the ice shelf from ESA’s webcam from space) The device transmitted data once every 6 days and scientists were eagerly waiting for its transmissions. Their predictions were confirmed in early April when satellite images from the European Space Agency showed the bridge was gone and had been replaced by chunks of ice. The Wilkins Ice Shelf is the tenth major ice shelf to collapse in recent times.
According to NASA, the collapse of the ice shelf will not contribute to sea level rise, since the ice had already been floating on the water. When other ice shelves such as the Larsen, have collapsed, they allowed glaciers to pump more ice into the ocean at a faster rate, which did contribute to sea level rise. The Wilkins Ice Shelf does not buttress any major glacier. However, the collapse of the shelf itself signals rising temperatures are affecting Antarctica’s ice.
NASA image acquired on March 31, 2009. In this image, taken by the MODIS instrument on NASA’s Terra satellite, the ice bridge was still intact. The ice appears to be smooth, an unbroken surface. #
NASA image acquired on April 6, 2009. Less than a week later the MODIS instrument on NASA’s Aqua satellite captured the above image. The smooth bridge is gone, replaced by chunks of ice. The pieces of the former ice bridge join multiple other chunks of ice formed as the northern portion of the ice shelf broke apart throughout the previous decade. The broken pieces of the shelf have remained frozen in place since 1998, but now that the ice bridge no longer provides a barrier, the remnants of the ice shelf may flow out into the Southern Ocean. The southern portion of the Wilkins Ice Shelf (part of which appears in the lower right corner of the images) is still intact, but may be more vulnerable now that the northern edge has disintegrated. #
This NASA handout Terra satellite image obtained on April 21, 2009 shows The Wilkins Ice Shelf, on the western side of the Antarctic Peninsula, as it experienced multiple disintegration events in 2008. By the beginning of 2009, a narrow ice bridge was all that remained to connect the ice shelf to ice fragments fringing nearby Charcot Island. That bridge gave way in early April 2009. Days after the ice bridge rupture, on April 12, 2009, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite acquired this image of the southern base of the ice bridge, where it connected with the remnant ice shelf. Although the ice bridge has played a role in stabilizing the ice fragments in the region, its rupture doesn’t guarantee the ice will immediately move away. (HO/AFP/Getty Images) #
This handout photo provided by the European Space Agency (ESA) on April 28, 2009 shows a satellite image of the destabilised Wilkins Ice Shelf taken on April 27, 2009 superimposed on an image from April 24, 2009. These images show that icebergs have begun to calve from the northern front of the Wilkins Ice Shelf, indicating that the huge shelf has become unstable, according to the ESA. The ice bridge, which effectively formed a barrier pinning back the northern ice front of the central Wilkins Ice Shelf, the ESA says, collapsed on April 5 which removed some 330sq km of ice. (HO/AFP/Getty Images) #
This image is a composite of NASA’s Blue Marble data set from the early 2000’s. Some Ice Shelves on the image do not exist anymore. The Larsen A Ice Shelf, previously located north of the Larsen B Ice Shelf had previously broken up and reformed only about 4,000 years ago but disintegrated in January 1995. The Larsen B Ice Shelf, which had been stable for at least 10,000 years, disintegrated in February 2002. #
In this image from late February 2008, part of the Wilkins Ice Shelf on the Antarctic Peninsula disintegrated into a floating pile of massive ice bergs, smaller ice fragments, and slush that was trapped in place by freezing sea water over subsequent weeks. The dramatic event was first spotted in NASA satellite imagery by Ted Scambos, lead scientist at the National Snow and Ice Data Center. Over the following days, international collaborators used images from satellites and aircraft to track the event. This highly detailed image from the Taiwanese Formosat-2 satellite shows the different sizes, shapes, and textures of the ice fragments on March 8, 2008. Several large icebergs float amid a mosaic of smaller pieces of ice. The level of detail in the image is so great that it can seem as though you are standing over a scale model made out of papier-mâché and foam blocks. The detail can make the bergs seem deceptively small. In reality, some of the large bergs are several hundred meters (yards) long. #
Arctic Ice Cover
On the same day of the ice bridge collapse, NASA released images and reports on the ice coverage of the opposite pole. The arctic ice is rapidly thinning. NASA released composites showing the average age of the arctic ice. The Arctic ice cap grows each winter as the sun sets for several months and extreme cold sets in. Thicker, older ice that survives more than one summer is more likely to endure the following summer. (See a time lapse of Arctic Ice, from 1979 through 2005) Until recently, the majority of Arctic sea ice survived at least one summer. Arctic ice cools the global climate system, and reflects solar radiation back into space. Scientists at the National Snow and Ice Data Centre at the University of Colorado, where the research was carried out, said thinner sea ice is less likely to survive the summer and predicted the Arctic Ocean will be effectively ice free sometime between 2020 and 2040, although it is possible it could happen as early as 2013. See an animated images of Ice Cover and Ice Age from September 2008 through February 2009.
A Jewish settler walks outside a disputed building in the West Bank town of Hebron, Sunday, Nov. 23, 2008. Israel's deputy defense minister says the country will remove Jewish settlers who are holed up in a disputed house in the Palestinian city of Hebron in violation of a Supreme Court eviction order. (AP Photo/Sebastian Scheiner) #
Retreating Glaciers
While scientists believe the ice caps are melting because of the warmer ocean temperatures, they believe glaciers are retreating because they are sensitive to the temperature and precipitation changes that come with global climate change. While certain types of glaciers—such as surge glaciers and tidewater glaciers—are actually expanding, there are many areas where scientists report glaciers are wasting away. Across the globe and the nation, scientists are studying the retreat of these glaciers. Part of their research is doing what are called Repeat Photography Projects. Both the U.S. Geological Survey and The National Snow and Ice Data Center at the University of Colorado are conducting these projects. The USGS’s repeat photography project is centered in Glacier National Park while the NSIDC’s photographs mainly center on Alaskan Glaciers. All the pairings below come from these two studies.
Bear Glacier, Alaska
Bear Glacier 1920 (Unknown Photographer, courtesy of National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
Bear Glacier 2005 (Bruce F. Molnia, courtesy of National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
Bear Glacier, Alaska
Bear Glacier 1909 (Ulysses Sherman Grant, courtesy of National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
Bear Glacier 2005 (Bruce F. Molnia, courtesy of National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
Carroll Glacier, Alaska
Carroll Glacier 1906 (Charles Will Wright, courtesy of the USGS Photo Library, Denver, Colorado) North-looking photograph taken on Triangle Island, Queen Inlet, Glacier Bay National Park and Preserve, Alaska. #
Carroll Glacier 2003 (Bruce F. Molnia, courtesy of the U.S. Geological Survey) North-looking photograph taken on Triangle Island, Queen Inlet, Glacier Bay National Park and Preserve, Alaska. #
Holgate Glacier, Alaska
Holgate Glacier 1909. (Ulysses Sherman Grant, courtesy of the USGS Photo Library, Denver, Colorado) Northwest-looking photograph taken from near the head of Holgate Arm, Aialik Bay, Kenai Fjords National Park, Alaska. #
Holgate Glacier 2004. (Bruce F. Molnia, courtesy of the U.S. Geological Survey) Northwest-looking photograph taken from near the head of Holgate Arm, Aialik Bay, Kenai Fjords National Park, Alaska. #
McCall Glacier, Alaska
McCall Glacier 1958. (Austin Post, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
McCall Glacier 2004. (Matt Nolan, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
McCarty Glacier, Alaska
McCarty Glacier 1909. (Ulysses Sherman Grant, courtesy of the U.S. Geological Survey) Northwest-looking photograph taken from about 5 miles north of the mouth of the McCarty Fjord, Kenai Fjords National Park, Alaska. #
McCarty Glacier 2004. (Bruce F. Molnia, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) Northwest-looking photograph taken from about 5 miles north of the mouth of the McCarty Fjord, Kenai Fjords National Park, Alaska. #
McCarty Glacier, Alaska
McCarty Glacier 1909. (Ulysses Sherman Grant, courtesy of the USGS Photo Library, Denver, Colorado) Northeast-looking photograph taken from about 5 miles north of the mouth of McCarty Fjords, Kenai Fjords National Park, Alaska. #
McCarty Glacier 2004. (Bruce F. Molnia, courtesy of the U.S. Geological Survey) Northeast-looking photograph taken from about 5 miles north of the mouth of McCarty Fjords, Kenai Fjords National Park, Alaska. #
Muir Glacier, Alaska
Muir Glacier 1880. (G.D. Hazard, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
Muir Glacier 2005. (Bruce F. Molnia, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
Muir Glacier, Alaska
Muir Glacier 1890. (Harry Fielding Reid, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) West end of Muir Glacier terminus, Morse Glacier and Steamer City of ? (Possibly Topeka or Tacoma) from near Camp Muir. Northwest view. #
Muir Glacier 2005. (Bruce F. Molnia, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) West end of Muir Glacier terminus, Morse Glacier and Steamer City of ? (Possibly Topeka or Tacoma) from near Camp Muir. Northwest view. #
Muir Glacier, Alaska
Muir Glacier 1892. (Harry Fielding Reid, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) Mt. Case at right, shoulder of Mt. Wright at extreme right. East view. #
Muir Glacier 2005. (Bruce F. Molnia, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) Mt. Case at right, shoulder of Mt. Wright at extreme right. East view. #
Muir Glacier, Alaska
Muir Glacier 1941. (William O. Field, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) Taken from photo Station 4 established in 1941 by W.O. Field on White Thunder Ridge, Muir Inlet, Glacier Bay National Park and Preserve, Alaska. #
Muir Glacier 2004. (Bruce F. Molnia, courtesy of the U.S. Geological Survey) Taken from photo Station 4 established in 1941 by W.O. Field on White Thunder Ridge, Muir Inlet, Glacier Bay National Park and Preserve, Alaska. #
Northwestern Glacier, Alaska
Northwestern Glacier 1909. (Ulysses Sherman Grant, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
Northwestern Glacier 2005. (Bruce F. Molnia, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
Northwestern Glacier, Alaska
Northwestern Glacier 1940. (Unknown Photographer, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
Northwestern Glacier 2005. (Bruce F. Molnia, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
Okpilak Glacier, Alaska
Okpilak Glacier 1907. (Ernest Leffingwell, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
Okpilak Glacier 2004. (Matt Nolan, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
Pedersen Glacier, Alaska
Pedersen Glacier 1917. (Louis H. Pedersen, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
Pedersen Glacier 2005. (Bruce F. Molnia, courtesy of the National Snow and Ice Data Center/World Data Center for Glaciology, Boulder) #
Toboggan Glacier, Alaska
Toboggan Glacier 1909. (Sidney Paige, courtesy of the USGS Photo Library, Denver, Colorado) North-looking photograph taken from an offshore location of Toboggan Glacier, Harriman Fiord, Prince William Sound, Chucagh National Forest, Alaska. #
Toboggan Glacier 2000. (Bruce F. Molnia, courtesy of the U.S. Geological Survey) North-looking photograph taken from an offshore location of Toboggan Glacier, Harriman Fiord, Prince William Sound, Chucagh National Forest, Alaska. #
Unnamed Glacier, Alaska
Unnamed Glacier 1919. (Stephen Reid Capps, courtesy of the USGS Photo Library, Denver, Colorado) North-looking photograph taken near the retreating unnamed valley glacier that forms the East Fork of the Teklanika River, Denali National Park and Preserve, Alaska. #
Unnamed Glacier 2004. (Ron Karpilo, courtesy of the National Park Service) North-looking photograph taken near the retreating unnamed valley glacier that forms the East Fork of the Teklanika River, Denali National Park and Preserve, Alaska. #
Boulder Glacier, Glacier National Park, Montana
Boulder Glacier Ice Cave 1932. (T.J. Hileman, courtesy of the GNP Archives) #
Boulder Glacier Ice Cave 1988. (Jerry DeSanto, courtesy of the USGS Repeat Photography Project) #
Boulder Glacier, Glacier National Park, Montana
Boulder Glacier 1932. (T.J. Hileman, courtesy of the GNP Archives) #
Boulder Glacier 2005. (Greg Pederson, courtesy of the USGS Repeat Photography Project) #
Boulder Glacier, Glacier National Park, Montana
Boulder Glacier from Chapman Peak 1910. (M. Elrod, courtesy of the GNP Archives) #
Boulder Glacier from Chapman Peak 2007. (Dan Farge & Greg Pederson, courtesy of the USGS Repeat Photography Project) #
Chaney Glacier, Glacier National Park, Montana
Chaney Glacier Terminus 1911. (M.R. Campbell, courtesy of the USGS Photographic Library) #
Chaney Glacier Terminus 2005. (Blase Reardon, courtesy of the USGS Repeat Photography Project) #
Grinnell Glacier, Glacier National Park, Montana
Grinnell Glacier from Mt. Gould 1938. (T.J. Hileman, courtesy of the GNP Archives) #
Grinnell Glacier from Mt. Gould 2006. (Karen Holzer, courtesy of the USGS Repeat Photography Project) #
Grinnell Glacier, Glacier National Park, Montana
Grinnell Glacier, North Moraine 1922. (Morton Elrod, courtesy of the K. Ross Toole Archives, Mansfield Library, University of Montana) #
Grinnell Glacier, North Moraine 2008. (Lisa McKeon, courtesy of the USGS Repeat Photography Project) #
Grinnell Glacier, Glacier National Park, Montana
Grinnell Glacier, from the Trail 1911. (Stanton, courtesy of the GNP Archives) #
Grinnell Glacier, from the Trail 2008. (Lisa McKeon, courtesy of the USGS Repeat Photography Project) #
Shepard Glacier, Glacier National Park, Montana
Shepard Glacier 1913. (W.C. Alden, courtesy of the USGS Photographic Library) #
Shepard Glacier 2005. (Blase Reardon, courtesy of the USGS Repeat Photography Project) #
Sperry Glacier, Glacier National Park, Montana
Sperry Glacier circa 1930. (Morton Elrod, courtesy of the K. Ross Toole Archives, Mansfield Library, University of Montana) #
Sperry Glacier 2008. (Lisa McKeon, courtesy of the USGS Repeat Photography Project) #
Thunderbird Glacier, Glacier National Park, Montana
Thunderbird Glacier 1907. (Morton Elrod, courtesy of the GNP Archives) #
Sea Level Rise Due to Global Warming Poses Threat to New York City
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