Erosion from beneath could lead to more sea-level rise
Oceans warming under a thickening blanket of greenhouse gases are licking at the edge of Antarctica and carving new channels in the bottom of ice shelves all around the frozen continent, researchers said this week in a new study led by scientists with the National Snow and Ice Data Center.
Those channels, characterized as “upside-down rivers” by the scientists, may make the ice shelves more prone to collapsing, which could speed up the flow of ice and the increase the rate of sea-level rise. Overall, some Antarctic ice sheets have thinned by about 18 percent and the rate of melting is accelerating, other research shows.
New ice core study helps pinpoint global warming impacts
After studying a new ice core sample from McMurdo Sound, researchers say they’re a bit closer to one of the holy grails of climate science — understanding how Antarctic ice sheets will respond to increasing concentrations of atmospheric carbon dioxide.
The scientists looked at a 3,735-foot sediment core to reconstruct the Antarctic ice sheets’ history in an effort to create a climate model that mirrors conditions during the Miocene Era, when atmospheric CO2 levels were slightly higher, at 500 parts per million, than the 400 ppm level reached just last year, and global average temperatures were about 3 to 4 degrees Celsius higher than today. Continue reading “Antarctic ice sheets may be more sensitive to CO2 than we thought”→
‘It is high time that this essential irreversibility is placed into the focus of policy-makers’
Today’s debates about global warming impacts are much too shortsighted, according to a new analysis, which warns that, at the current rate of greenhouse gas emissions, the Earth is likely to suffer irreparable damage that could last tens of thousands of years.
“Much of the carbon we are putting in the air from burning fossil fuels will stay there for thousands of years – and some of it will be there for more than 100,000 years,” said Oregon State University paleoclimatologist Peter Clark. “People need to understand that the effects of climate change on the planet won’t go away, at least not for thousands of generations,” said Clark, lead author of the article. Continue reading “Policy makers must take long-term view of climate change”→
‘All signs suggest the ice from West Antarctica could disappear relatively quickly …’
An in-depth survey of Antarctica’s rugged Ellsworth Mountains suggests that the West Antarctic Ice Sheet could melt quickly under the influence of global warming, potentially raising global sea level by three meters.
Heat trapped by greenhouse gases is building up in the oceans at an increasing rate, according to researchers who are trying to get a more detailed understanding of the oceans’ role in the global climate cycle.
After studying data from a variety of sources, the researchers with Lawrence Livermore National Laboratory andthe National Oceanic and Atmospheric Administration found that half of the global ocean heat content increase since 1865 has occurred over the past two decades. Continue reading “Climate: Ocean heat buildup is accelerating”→
Study shows that 2012 melting created a dense ice cap
When warm temperatures in 2012 caused an extreme melting episode across much of the Greenland Ice Sheet, it may have fundamentally altered the way the near-surface snow layers absorb water, according to a new study published in Nature Climate Change.
If world leaders need one more sign that they must reach a decisive climate agreement this week in Paris, it might be a new study showing that Greenland’s glaciers are retreating at least twice as fast as any other time in the past 9,500 years.