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arctic

Could Rudolph and friends help to slow down our warming climate?

Reindeer may be best known for pulling Santa’s sleigh, but a new study suggests they may have a part to play in slowing down climate change too.A team of researchers, writing in the journal Environmental Research Letters, found that when reindeer reduce the height and abundance of shrubs on the Arctic tundra through grazing, the level of surface albedo – the amount of solar energy (shortwave radiation) reflected by the Earth back into space – is increased. 

Sea ice hit record lows in November

Unusually high air temperatures and a warm ocean have led to a record low Arctic sea ice extent for November, according to scientists at the National Snow and Ice Data Center (NSIDC) at the University of Colorado Boulder. In the Southern Hemisphere, Antarctic sea ice extent also hit a record low for the month, caused by moderately warm temperatures and a rapid shift in circumpolar winds.“It looks like a triple whammy—a warm ocean, a warm atmosphere, and a wind pattern all working against the ice in the Arctic,” said NSIDC director Mark Serreze.

Changing Arctic Tundra Could Radically Alter Shorebird Breeding Grounds

A new study projects that global warming could dramatically affect the tundra breeding habitat of 24 shorebird species, with 66 percent to 83 percent losing most of their suitable nesting territories. Researchers modeled breeding conditions for these migratory shorebird species — some of which travel more than 10,000 miles from Antarctica or southern South America to breed in the Arctic — and compared projected 21st century conditions to the last major warming event more than 6,000 years ago. 

Ice algae: The engine of life in the central Arctic Ocean

Algae that live in and under the sea ice play a much greater role for the Arctic food web than previously assumed. In a new study, biologists of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) showed that not only animals that live directly under the ice thrive on carbon produced by so-called ice algae. Even species that mostly live at greater depth depend to a large extent on carbon from these algae. This also means that the decline of the Arctic sea ice may have far-reaching consequences for the entire food web of the Arctic Ocean. Their results have been published online now in the journal Limnology & Oceanography.The summer sea ice in the Arctic is diminishing at a rapid pace and with it the habitat of ice algae. The consequences of this decline for the Arctic ecosystem are difficult to predict. Scientists of the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research showed the significance of ice algae for the Arctic food web in this context. “A number of studies have already speculated that ice algae are an important energy source for the polar ecosystems. We have now been able to show that not only animals associated with ice meet the majority of their carbon needs from ice algae, but that, surprisingly, so do species that mostly live at greater depths,” says lead author Doreen Kohlbach.

Low ice, low snow, both poles

Daily Arctic sea ice extents for May 2016 tracked two to four weeks ahead of levels seen in 2012, which had the lowest September extent in the satellite record. Current sea ice extent numbers are tentative due to the preliminary nature of the DMSP F-18 satellite data, but are supported by other data sources. An unusually early retreat of sea ice in the Beaufort Sea and pulses of warm air entering the Arctic from eastern Siberia and northernmost Europe are in part driving below-average ice conditions. Snow cover in the Northern Hemisphere was the lowest in fifty years for April and the fourth lowest for May. Antarctic sea ice extent grew slowly during the austral autumn and was below average for most of May.

NASA studies details of a greening Arctic

The northern reaches of North America are getting greener, according to a NASA study that provides the most detailed look yet at plant life across Alaska and Canada. In a changing climate, almost a third of the land cover – much of it Arctic tundra – is looking more like landscapes found in warmer ecosystems.With 87,000 images taken from Landsat satellites, converted into data that reflects the amount of healthy vegetation on the ground, the researchers found that western Alaska, Quebec and other regions became greener between 1984 and 2012. The new Landsat study further supports previous work that has shown changing vegetation in Arctic and boreal North America.

The North Pole had ice-free summers millions of years ago

An international team of scientists led by the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI) have managed to open a new window into the climate history of the Arctic Ocean. Using unique sediment samples from the Lomonosov Ridge, the researchers found that six to ten million years ago the central Arctic was completely ice-free during summer and sea-surface temperature reached values of 4 to 9 degrees Celsius. In spring, autumn and winter, however, the ocean was covered by sea ice of variable extent, the scientists explain in the current issue of the journal Nature Communications. These new findings from the Arctic region provide new benchmarks for groundtruthing global climate reconstructions and modelling.The researchers had recovered these unique sediment samples during an expedition with Germany's research icebreaker RV Polarstern in summer of 2014. “The Arctic sea ice is a very critical and sensitive component in the global climate system. It is therefore important to better understand the processes controlling present and past changes in sea ice

Warming Arctic being exploited by trawlers

Ice melt in the Arctic Ocean is opening up previously untouched areas to industrial fishing fleets using ecologically risky bottom trawling methods, writes Joe Sandler Clarke. Ecosystems supporting walruses, polar bears, puffins and other sea birds could be stripped bare.Bottom trawling is widely considered to be the among most destructive fishing techniques, with vast nets catching fish as they are dragged along the sea bed.Using official data and ship tracking systems, researchers found that large numbers of fishing vessels owned by major companies have taken advantage of melting sea ice to fish in previously impossible to reach parts of the Norwegian and Russian Arctic.

2015 Year in Review

As 2015 comes to a close, Mongabay is looking back at the year that was. This year saw President Obama reject the Keystone pipeline as historic droughts and a vicious wildfire season wracked the western US and Canada. The world committed to climate action in Paris as Southeast Asia was choking on the worst Indonesian haze in years, Shell aborted its plans to drill in the Arctic for the “foreseeable” future, and ExxonMobil is being investigated for lying to the public about climate risks. Here, in no certain order, are the top 15 environmental stories of 2015.

A million years ago, Greenland was ice free

As the Arctic warms, Greenland’s fringe of glaciers is thinning and melting—but the future of the Greenland ice sheet remains a giant question mark. Until recently, that was also true of the ice sheet’s past: Scientists have long debated whether it might have shrunk away to nothing during Earth’s warmest periods. Now, a new study suggests that Greenland was entirely ice free at some point in the last 1.25 million years.“We should be worried about the Greenland Ice Sheet,” says Joerg Schaefer, a geochemist from Columbia University’s Lamont-Doherty Earth Observatory in Palisades, New York, and lead author of the findings, presented yesterday at the American Geophysical Union’s annual meeting here.