Posted on July 11, 2015 by Bob Berwyn
‘The ominous aspect to this is that CO2 levels are continuing to rise, so we are entering uncharted territory …’
This graph shows cumulative changes in sea level for the world’s oceans since 1880, based on a combination of tide gauge measurements and satellite measurements. Graph courtesy EPA.
The Florida coastline is being swallowed by rising sea level despite efforts to bolster beaches. @bberwyn photo.
FRISCO — It doesn’t take much global warming to raise sea level by 20 feet or more, climate researchers said in a new review study finding 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.
An increase of just 1 to 2 degrees Celsius in global mean temperatures is enough trigger a big meltdown of Greenland and Antarctic ice, which means that the world’s coastal areas are going to be swamped in the global warming era — it’s just a question of whether it will take a few hundred, or a few thousand years.
“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, who co-authored the new study appearing in Science. Continue reading
Filed under: climate and weather, climate change, global warming | Tagged: climate change, CO2, global sea level rise, global warming, greenhouse gas pollution, sea level | 2 Comments »
Posted on February 5, 2015 by Bob Berwyn
New research shows that even the frigid fringes of East Antarctica are melting away under warming seas.
Warming ocean melts ice from below
FRISCO — It’s not just the West Antarctic ice sheets that are melting away as the surrounding ocean warms, Australian scientists reported after a six week voyage to the eastern side of the frozen continent.
A series of detailed measurements show that warm ocean water is melting the Totten Glacier — the largest in the region, with enough ice to raise sea level by several meters, according to the findings by the Australian Antarctic Division and partnering research organizations. Continue reading
Filed under: Antarctica, climate and weather, Environment, global warming | Tagged: Antarctica, climate change, East Antarctica, sea level, Totten Glacier | 1 Comment »
Posted on January 22, 2015 by Bob Berwyn
New data to help inform projections of sea-level rise
FRISCO — Drilling deep into Antarctic ice this month, researchers were able for the first time to take a close look at the grounding zone of an ice sheet, where Antarctic ice, land and sea all converge.
Sediment samples from the half-mile bore hole will provide clues about the mechanics of ice sheets and their potential effects on sea-level rise, but the drilling also revealed an unsuspected population of fish and invertebrates living beneath the ice sheet, the farthest south that fish have ever been found. Continue reading
Filed under: Antarctica, climate and weather, Environment, global warming | Tagged: Antarctica, climate change, Environment, Ross Ice Shelf, Ross Sea, sea level | Leave a comment »
Posted on December 5, 2014 by Bob Berwyn
New research shows signs of a major meltdown in Antarctica. bberwyn photo.
Ocean temperatures increasing steadily near West Antarctica
FRISCO — Warming seawater around parts of Antarctica is speeding the melting and sliding of glaciers, and that there is no indication that this trend will reverse, according to researchers with the University of East Anglia.
The study, published in the journal Science, tracked ocean temperatures in the shallow shelf seas of West Antarctica for the last 50 years. The findings also suggest the areas of warmer seawater are spreading, and that other Antarctic areas, which have not yet started to melt, could experience melting for the first time, which would increase the pace of global sea level rise. Continue reading
Filed under: Antarctica, climate and weather, Environment, global warming | Tagged: climate change, global warming, sea level, Southern Ocean warming, University of East Anglia, West Antarctic Ice Sheet | 1 Comment »
Posted on October 2, 2014 by Bob Berwyn
‘The big question is whether the ice sheet will react to these changing ocean conditions as rapidly as it did 14,000 years ago’
FRISCO — A stratification of the ocean around Antarctica could lead to more rapid melting of ice sheets, triggering a sudden surge in sea level rise. That last time that happened was well before the global warming era, about 14,000 years ago, but scientists are now seeing signs of a similar pattern.
A new study found that in the past, when ocean temperatures around Antarctica became more layered, with a warm layer of water below a cold surface layer, ice sheets and glaciers melted much faster than when the cool and warm layers mixed more easily. This defined layering of temperatures is exactly what is happening now around the Antarctic.
“The reason for the layering is that global warming in parts of Antarctica is causing land-based ice to melt, adding massive amounts of freshwater to the ocean surface,” said ARC Centre of Excellence for Climate System Science researcher Prof Matthew England, an author of the paper, published in Nature Communications.
Filed under: climate and weather, global warming | Tagged: Antarctica, climate change, global warming, sea level, Southern Ocean | Leave a comment »
Posted on September 25, 2014 by Bob Berwyn
If sea levels rose to where they were during the last Interglacial Period, large parts of the Gulf of Mexico would be under water (red areas), including half of Florida and several Caribbean islands. Credit: Jeremy Weiss, Department of Geosciences, The University of Arizona.
‘Once under way, this response may be irreversible for many centuries to come’
FRISCO — Melting ice caps caused global sea level to rise by up to 30 feet per century during the ending phases of the last five ice ages, researchers said, announcing results of a study that traces sea level fluctuations across a span of half a million years.
The record shows that sea level changes can happen quickly on a geological time scale, and that there were hundreds of smaller pulses in sea level in between the five major events. But the biggest changes in sea level happened after periods when ice sheets were much larger than today’s. Continue reading
Filed under: climate and weather, Environment, global warming | Tagged: climate change, global warming, ice age, sea level | 1 Comment »
Posted on August 31, 2014 by Bob Berwyn
‘The interaction between air, sea and ice in these seas is central to the stability of the Antarctic Ice Sheet and global sea levels’
A new study tracks global warming impacts around Antarctica. bberwyn photo.
By Summit Voice
FRISCO — Global warming is upsetting the delicate balance between Antarctic ice, air and sea, University of Southampton scientists said this week, releasing results of a study showing a rapid rise in sea level around the frozen continent.
Based on an analysis of 19 years worth of satellite data, the researcher said sea level around the coast of Antarctica has climbed 2 centimeters more than the global average, driven almost entirely by an increase in freshwater, which is less dense than saltwater. That can cause localized increases in sea level, said Craig Rye, lead author of the paper published in the journal Nature Geoscience. Continue reading
Filed under: Antarctica, climate and weather, Environment, global warming | Tagged: Antarctica, climate change, Environment, global warming, sea level | Leave a comment »