Fire Earth

Mass die-offs from human impact and planetary response to the assault could occur by early 2016

Posts Tagged ‘arctic mammals’

Guess what, the Arctic temps are 5 ºC warmer!

Posted by feww on October 17, 2008

Who’s Afraid of the Heating Arctic?

Arctic fall temperatures are at a record 5 ºC above normal

Fall temperatures in the Arctic are a record 5 ºC warmer than the average as less sunlight is reflected because of the major loss of sea ice  allowing  more solar heating of the ocean to occur, NOAA reported. Winter and springtime temperatures remain relatively warm over the entire Arctic, in contrast to the 20th century and consistent with an emerging global warming influence.

The Arctic-wide warming trend that began about 4 decades ago continues, with 2007 recorded as the warmest year ever for the Arctic.


Arctic-wide annual averaged surface air temperature anomalies (60°–90°N) based on land stations north of 60°N relative to the 1961–90 mean.

As more more of the ice cover was lost during the the 2005 to 2007 melt season, the ocean absorbed more heat from solar radiation which resulted in the ice freeze-up occurring later than usual.  Surface air temperature (SAT) remained high into the following autumns, with warm anomalies above an unprecedented +5 °C during October and November across the central Arctic. Report summary.


Near surface air temperature anomaly map for October and November for recent years with a reduced sea ice cover, 2005–2007. Data are from the NCEP – NCAR reanalysis through the NOAA /Earth Systems Research Laboratory, generated online CDC/NOAA.

“Changes in the Arctic show a domino effect from multiple causes more clearly than in other regions,” said James Overland, an oceanographer at NOAA’s Pacific Marine Environmental Laboratory in Seattle and one of the authors of the report, Atmosphere.

“It’s a sensitive system and often reflects changes in relatively fast and dramatic ways.”


Ice breaks away from a frozen coastline near the Norwegian Arctic town of Longyearbyen April 23, 2007, an earlier than usual spring thaw. REUTERS/Francois Lenoir (NORWAY). Image may be subject to copyright.

Hell hath no fury like a planet with little autumn ice!

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Posted in atmosphere, Climate Change, heating ocean, sea ice cover, solar heating of the ocean | Tagged: , , , , | 4 Comments »

Arctic Marine Mammals on Thin Ice

Posted by feww on April 24, 2008

(source: Ecological Society of America)

Experts outline primary risks of climate change to natives of the Arctic

The loss of sea ice due to climate change could spell disaster for polar bears and other Arctic marine mammals. The April Special Issue of Ecological Applications examines such potential effects, puts them in historical context, and describes possible conservation measures to mitigate them. The assessment reflects the latest thinking of experts representing multiple scientific disciplines.

Sea ice is the common habitat feature uniting these unique and diverse Arctic inhabitants. Sea ice serves as a platform for resting and reproduction, influences the distribution of food sources, and provides a refuge from predators. The loss of sea ice poses a particularly severe threat to Arctic species, such as the hooded seal, whose natural history is closely tied to, and depends on, sea ice.

The Arctic undergoes dramatic seasonal transformation. Arctic marine mammals appear to be well adapted to the extremes and variability of this environment, having survived past periods of extended warming and
cooling.


Walrus – Odobenus rosmarus divergens – hauled out on Bering Sea ice, Alaska. (Photo Credit: Captain Budd Christman, NOAA Corps)

“However, the rate and scale of current climate change are expected to distinguish current circumstances from those of the past several millennia. These new conditions present unique challenges to the well-being of Arctic marine mammals,” says Sue Moore (NOAA/Alaska Fisheries Science Center).

Climate change will pose a variety of threats to marine mammals. For some, such as polar bears, it is likely to reduce the availability of their prey, requiring them to seek alternate food. Authors Bodil Bluhm and Rolf Gradinger (University of Alaska, Fairbanks) note that while some Arctic marine mammal species may be capable of adjusting to changing food availability, others may be handicapped by their very specific food requirements and hunting techniques. Species such as the walrus and polar bear fall under this category, while the beluga whale and bearded seal are among those who are more opportunistic in their eating habits and therefore potentially less vulnerable, at least in this regard.


Look here, General George, I can’t unzip the fur! (Photo Credit:Kathy Crane, NOAA Arctic Research Office.)

Using a quantitative index of species sensitivity to climate change, Kristin Laidre (University of Washington) and colleagues found that the most sensitive Arctic marine mammals appear to be the hooded seal, polar bear, and the narwhal, primarily due to their reliance on sea ice and specialized feeding.

Shifts in the prey base of Arctic marine mammals would likely lead to changes in body condition and potentially affect the immune system of marine mammals, according to Kathy Burek (Alaska Veterinary Pathology Services). She and fellow researchers point out that climate change may alter pathogen transmission and exposure to infectious diseases, possibly lowering the health of marine mammals and, in the worst case, their survival. Changing environmental conditions, including more frequent bouts of severe weather and rising air and water temperatures, also could impact the health of Arctic marine mammals.


Exasperated polar bears shoo the submarine USS Honolulu off their melting porch (450 km from the North Pole).

The effects of climate change will be compounded by a host of secondary factors. The loss of ice will open the Arctic to new levels of shipping, oil and gas exploration and drilling, fishing, hunting, tourism, and coastal development. These, in turn, will add new threats to marine mammal populations, including ship strikes, contaminants, and competition for prey.

Timothy Ragen (US Marine Mammal Commission) and colleagues describe how conservation measures may be able to address the secondary effects of climate change, but that only reductions in greenhouse gas emissions can-over the long-term-conserve Arctic marine mammals and the Arctic ecosystems on which they depend.

Ragen talks more about the issue on an Ecological Society of America podcast. Visit http://www.esa.org/podcast/ to listen to this latest edition of ESA’s podcast, Field Talk.

Lead authors of the collection of papers in the Special Supplement to Ecological Applications are:

John Walsh (U. of AK, Fairbanks)–climatological understanding C.R. Harrington (Canadian Museum of Nature)–evolutionary history of arctic marine mammals Maribeth Murray (U. of AK, Fairbanks)–past distributions of arctic marine mammals Gregory O’Corry-Crowe (Southwest Fisheries Science Center)–past and current distributions and behaviors Bodil Bluhm (U. of AK, Fairbanks)–food availability and implications of climate change Kristin Laidre (U. of WA)–sensitivity to climate-induced habitat change Kathy Burek (Alaska Veterinary Pathology Services)–effects on Arctic marine mammal health Grete Havelsrud (Center for International Climate & Environmental Research-Oslo)–human interactions Vera Metcalf (Eskimo Walrus Commission, Kawerak)–walrus hunting Sue Moore (NOAA/Alaska Fisheries Science Center)/Henry Huntington (Huntington Consulting)–resilience of Arctic marine mammals to climate change Timothy Ragen (U.S. Marine Mammal Commission)–conservation in context of climate change

The Ecological Society of America is the world’s largest professional organization of ecologists, representing 10,000 scientists in the United States and around the globe. Since its founding in 1915, ESA has promoted the responsible application of ecological principles to the solution of environmental problems through ESA reports, journals, research, and expert testimony to Congress. ESA publishes four journals and convenes an annual scientific conference. Visit the ESA website at http://www.esa.org.

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Posted in Climate Change, coastal development, energy, environment, exploration, food, gas, Global Warming, health, hunting, oil, polar bears, politics, shipping, Tourism, Travel | Tagged: , , , , , , , , , , , , , , , | 1 Comment »

 
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