Tag: sea level rising

  A new review analyzing three decades of research on the historic effects of melting polar ice sheets found that global sea levels have risen at least six meters, or about 20 feet, above present levels on multiple occasions over the past three million years. What is most concerning, scientists say, is that amount of melting was caused by an increase of only 1-2 degrees (Celsius) in global mean temperatures. Results of the study are being published this week in the journal Science. "Studies have shown that both the Greenland and Antarctic ice sheets contributed significantly to this sea level rise above modern levels," said Anders Carlson, an Oregon State University glacial geologist and paleoclimatologist, and co-author on the study. "Modern atmospheric carbon dioxide levels are today equivalent to those about three million years ago, when sea level was at least six meters higher because the ice sheets were greatly reduced. "It takes time for the warming to whittle down the ice sheets," added Carlson, who is in OSU's College of Earth, Ocean and Atmospheric Sciences, "but it doesn't take forever. There is evidence that we are likely seeing that transformation begin to take place now." Co-author Peter Clark, an ...

Click here for larger view of the image Alaska’s melting glaciers are adding enough water to the Earth’s oceans to cover the state of Alaska with a 1-foot thick layer of water every seven years, a new study shows. The study found that climate-related melting is the primary control on mountain glacier loss. Glacier loss from Alaska is unlikely to slow down, and this will be a major driver of global sea level change in the coming decades, according to the study’s authors. “The Alaska region has long been considered a primary player in the global sea level budget, but the exact details on the drivers and mechanisms of Alaska glacier change have been stubbornly elusive,” said Chris Larsen, a research associate professor with the Geophysical Institute at the University of Alaska Fairbanks. Larsen is lead author of the new study accepted for publication in Geophysical Research Letters, a journal of the American Geophysical Union. The UAF and U.S. Geological Survey research team analyzed surveys of 116 glaciers in the Alaska region across 19 years to estimate ice loss from melting and iceberg calving. The team collected airborne lidar altimetry data as part of NASA’s Operation IceBridge and integrated the ...