Scientists warn US east coast over accelerated sea level rise. A stormy Atlantic ocean hits the coast of Buxton, North Carolina.
Photographer: Ted Richardson/Bloomberg via Getty Images Sea level rise is accelerating three to four times faster along the densely populated east coast of the US than other US coasts, scientists have discovered. The zone, dubbed a "hotspot" by the researchers, means the ocean from Boston to New York to North Carolina is set to experience a rise up a third greater than that seen globally. Asbury Sallenger, at the US geological survey at St Petersburg, Florida, who led the new study, said: "That makes storm surges that much higher and the reach of the waves that crash onto the coast that much higher.
In terms of people and communities preparing for these things, there are extreme regional variations and we need to keep that in mind. Impacts & Adaptation. Sea Levels Rising Fast on U.S. East Coast. Charles Q.
Choi (Also see "New York, Boston 'Directly in Path' of Sea Level Rise. " ) Sea levels worldwide are expected to rise as global warming melts ice and causes water to expand. Those levels, though, are expected to vary from place to place, due to factors such as ocean currents, differences in seawater temperature and saltiness, and the Earth 's shape. Now it seems scientists have pinpointed just such a variance.
Analyzing tide-level data from much of North America, U.S. Global sea level rise averaged about 0.6 to 1 millimeter annually over the same period. "If you talk with residents of this hot spot area in their 70s or 80s who've lived there all their lives, they'll tell you water is coming higher now in winter storms than it ever did before," said study co-author Peter Howd , an oceanographer contracted with the USGS. "We're now finally getting to the point where we can measure their observations with our highfalutin scientific instruments. " Change and Sea Level Rise. Melting of Glaciers and Ice Sheets One of the most pronounced effects of climate change has been melting of masses of ice around the world.
Glaciers and ice sheets are large, slow-moving assemblages of ice that cover about 10% of the world’s land area and exist on every continent except Australia. They are the world’s largest reservoir of fresh water, holding approximately 75% (1). Over the past century, most of the world’s mountain glaciers and the ice sheets in both Greenland and Antarctica have lost mass. Retreat of this ice occurs when the mass balance (the difference between accumulation of ice in the winter versus ablation or melting in the summer) is negative such that more ice melts each year than is replaced (2).
One of the best-documented examples of glacial retreat has been on Mount Kilimanjaro in Africa. Image from global-greenhouse-warming.com When researching glacial melting, scientists must consider not only how much ice is being lost, but also how quickly. Image from UNEP. Current sea level rise. Trends in global average absolute sea level, 1870–2008.[1] Changes in sea level since the end of the last glacial episode. Current sea level rise is about 3 mm/year worldwide. According to the US National Oceanic and Atmospheric Administration (NOAA), "this is a significantly larger rate than the sea-level rise averaged over the last several thousand years", and the rate may be increasing.[2] This rise in sea levels around the world potentially affects human populations in coastal and island regions[3] and natural environments like marine ecosystems.[4] Between 1870 and 2004, global average sea levels rose 195 mm (7.7 in), 1.46 mm (0.057 in) per year.[5] From 1950 to 2009, measurements show an average annual rise in sea level of 1.7 ± 0.3 mm per year, with satellite data showing a rise of 3.3 ± 0.4 mm per year from 1993 to 2009,[6] a faster rate of increase than previously estimated.[7] It is unclear whether the increased rate reflects an increase in the underlying long-term trend.[8]