Category: Arctic

How do Arctic sea ice changes affect whales?

Study tracks belugas in global warming era

 Adult beluga whales are migrating through fractured sea ice in the Alaskan Arctic.

Beluga whales migrating through fractured sea ice in the Alaskan Arctic. Photo by Vicki Beaver/NOAA.

Staff Report

The relationship between Arctic whales and sea ice is still largely a mystery, but there is increasing concern over how these species will adapt to climate related changes in sea ice. In a new study, researchers found the drastic sea ice changes under way in the Arctic could lead to more predation of beluga whales — and that could have “implications for population viability, ecosystem structure and the subsistence cultures that rely on them,” said Dr. Greg O’Corry-Crowe, a scientist with Florida Atlantic University. Continue reading “How do Arctic sea ice changes affect whales?”

Climate: Sea ice at both poles way below average

Antarctic sea ice retreat could set stage for ice shelf collapses

wef
Melting Greenland glaciers in September 2015, photographed from a passenger jet. @bberwyn photo.

Staff ReportMonths of above-average temperatures in the Arctic slowed the growth of sea ice formation to a crawl during the second half of October, the National Snow and Ice Data Center reported in its latest monthly update.The ice scientists said that, starting Oct. 20, Arctic sea ice started setting daily record lows for extent.  After mid-October, ice growth returned to near-average rates, but extent remained at record low levels through late October. Both sea surface and air temperatures have remained unusually high, extending from the surface high up into the atmosphere. Continue reading “Climate: Sea ice at both poles way below average”

Global hot streak continues in October

No let up in global warming spiral, especially in the Arctic

srg

Surface air temperature anomaly for October 2016 relative to the October average for the period 1981-2010. Source: ERA-Interim. (Credit: ECMWF, Copernicus Climate Change Service)

Staff Report

The average global temperature for October 2016 was 0.57 degrees Celsius above the 1981 to 2010 average, continuing a spell of “exceptional global warmth that has now lasted more than a year, according to the European Climate Change Service.

Global temperature anomalies topped out in February with the peak of El Niño, then declined in spring and rose again in summer, declining only slightly in September. The October departure from normal was only slightly lower in October,  just 0.07 degrees Celsius under the all-time record for the month, set just last year.

With the exception of June, each month from October 2015 to October 2016 has been more extreme than January 2007, which was previously the month with the warmest anomaly. Each month from August 2015 to September 2016 successively became the warmest on record for that particular month.

October 2016 was cooler than the 1981-2010 average over much of Europe, but warmer than average in the far north of the continent and over the Iberian Peninsula and Mediterranean.  Well-above normal temperatures also occurred over the USA and parts of Africa. Temperatures were most above normal over much of the Arctic and Antarctic, with record-low sea extent in both regions.

Temperatures were below average along the equator over the eastern Pacific Ocean, indicating weak La Niña conditions, over some oceanic regions of the southern hemisphere and over part of the North Atlantic. Other land areas with below-average temperatures include most of Australia, western and north-eastern Canada and much of the southern half of South America. The zone of below-average temperatures bounded north and south by above-average temperatures extended eastwards across Asia.

Averaging over twelve-month periods smooths out the shorter-term variations. Globally, the warmest twelve-month period on record is from October 2015 to September 2016, with a temperature 0.64 degrees Celsius above the 1981-2010 average.

Uncertainty in the global value is relatively high for the year 2005, but there is agreement between various datasets regarding:

  • the exceptional warmth of 2016, and to a lesser extent 2015;
  • the overall rate of warming since the late 1970s;
  • the sustained period of above-average values from 2001 onwards.

There is more variability in average European temperatures, but values are less uncertain because observational coverage of the continent is relatively dense. Twelve-month averages for Europe have been at a persistently high level for the last three years or so. They are nevertheless lower than the averages from around the middle of 2006 to the middle of 2007.

Global warming started earlier than you think

New study suggests climate is very sensitive to greenhouse gases

Despite ups and downs from year to year, global average surface temperature is rising. By the beginning of the 21st century, Earth’s temperature was roughly 0.5 degrees Celsius above the long-term (1951–1980) average. (NASA figure adapted from Goddard Institute for Space Studies.
Despite ups and downs from year to year, global average surface temperature is rising. By the beginning of the 21st century, Earth’s temperature was roughly 0.5 degrees Celsius above the long-term (1951–1980) average. (NASA figure adapted from Goddard Institute for Space Studies).

Staff Report

Although the rate of global warming has increased dramatically in the last few decades, a new study suggests that human activities have been driving climate change for the past 180 years. The findings suggest that global warming is not just a  20th century phenomenon, and that the climate system is, indeed, quite sensitive to the buildup of heat-trapping pollution.

The study was led by Nerilie Abram, of  The Australian National University, who  warming began during the early stages of the Industrial Revolution and started leaving a fingerprint in  the Arctic and tropical oceans around the 1830s, much earlier than scientists had expected. Continue reading “Global warming started earlier than you think”

Climate: Arctic sea ice melt slows slightly in July

Experts say record low now unlikely

sdfg
Summer sea ice off the east coast of Greenland. @bberwyn photo.

Staff Report

Cool and stormy weather in the Arctic during July slowed the rate of sea ice loss to just below average for the month,  making it less likely sea ice extent will dwindle to a record low, according to the latest update from the National Ice and Snow Data Center. But it all depends on conditions the next few months.

For the month, sea ice extent averaged 2.14 million square miles, the third-lowest for July since satellite records started in 1979. It was only the second month of 2016 that didn’t end with a record-low extent, according to the NSIDC. The sea ice extent in July was 73,000 square miles above the previous record low 637,000 square miles below the 1981 to 2010 long-term average. Through 2016, the rate of decline for the month of July is 28,070 square miles per year, about 7.3 percent per decade. Continue reading “Climate: Arctic sea ice melt slows slightly in July”

Abrupt climate change linked with ocean current shutdown

‘Rollercoaster’ temps prevailed as iceberg flotillas invaded North Atlantic

iceberg
Can Arctic icemelt shut down crucial ocean currents? @bberwyn photo.

Staff Report

By studying chemical tracers in seafloor sediments, scientists have been able to show that periods of abrupt climate change during the last ice age are somehow linked with dramatic changes in key ocean currents, especially the Atlantic meridional overturning circulation, which carries heat from the tropics to the northern latitudes.

Specifically, the study looked at series of abrupt climate changes that occurred between 60,000 and 25,000 years ago, ending as the last ice age peaked. A press release on the study describes it as an era when “temperatures in the Northern Hemisphere went on a rollercoaster ride, plummeting and then rising again every 1,500 years or so.”

“People have long supposed this link between overturning circulation and these abrupt climate events. This evidence implicates the ocean,” said L. Gene Henry, the lead author of the study and a graduate student at Columbia University’s Lamont-Doherty Earth Observatory. The findings, published in the journal Science, show for the first time that the ocean’s overturning circulation slowed during every one of those temperature plunges — at times almost stopping. Continue reading “Abrupt climate change linked with ocean current shutdown”

Reaching Paris climate goals would help polar bears survive

New research suggests that capping global warming below 2 degrees Celsius would lower chances of big population decline by preserving critical sea ice

 Eric Regehr, U.S. Fish and Wildlife Service
Can these mighty Arctic predators survive the era of human-caused global warming?  Photo courtesy Eric Regehr, U.S. Fish and Wildlife Service.

Staff Report

Now that the world has a clear target for limiting global warming, scientists say they show how how achieving the goal would protect at least some ecosystems and vulnerable species from impacts.

One newly updated study found that aggressively cutting greenhouse gas emissions would help ensure the survival of polar bears, listed as threatened because of Arctic sea ice declines. Polar bears depend on the ice as platforms for feeding around the biologically rich continental shelves of the Arctic Ocean. Continue reading “Reaching Paris climate goals would help polar bears survive”