Most polar bears to disappear by 2100, study predicts

Most polar bears to disappear by 2100, study predicts

SOURCE: The Guardian DATE: July 20, 2020 SNIP: Scientists have predicted for the first time when, where and how polar bears are likely to disappear, warning that if greenhouse gas emissions stay on their current trajectory all but a few polar bear populations in the Arctic will probably be gone by 2100. By as early as 2040, it is very likely that many polar bears will begin to experience reproductive failure, leading to local extinctions, according to a study published in Nature Climate Change. The study examines how the bears will be affected under two different greenhouse gas emissions scenarios. The researchers found that under a business-as-usual emissions scenario, polar bears will likely probably only remain in the Queen Elizabeth Islands – the northernmost cluster in Canada’s Arctic archipelago – at the end of the century. And even if greenhouse gases are moderately mitigated, it is still likely that the majority of polar bear populations in the Arctic will experience reproductive failure by 2080. Scientists estimate that there are fewer than 26,000 polar bears left, spread out across 19 different subpopulations that range from the icescapes of Svalbard, Norway, to Hudson Bay in Canada to the Chukchi Sea between Alaska and Siberia. Polar bears are unable to find enough sustenance on land and rely on sea ice from which to hunt. They often stake out seal breathing holes in the ice, waiting hours for a blubbery meal to break the surface. But as that sea ice declines because of climate change, so, too, will the polar bears. Polar bears draw on energy reserves built up during the winter hunting...
Climate crisis: North pole ‘soon to be ice free in summer’, scientists say

Climate crisis: North pole ‘soon to be ice free in summer’, scientists say

SOURCE: The Independent DATE: April 20, 2020 SNIP: The Arctic Ocean will likely be ice-free during summers before 2050, researchers say. Amid rapid global warming – with average Arctic temperatures already 2C above what they were in the pre-industrial era – the extent of the sea ice is diminishing ever faster. As the climate crisis worsens, scientists say it is now only the efficacy of protection measures which will determine for how many more years our planet will continue to have a northern ice cap year round. A major new piece of research involving 21 leading institutes and using 40 different climate models has found that whatever action is taken, we are on course to see ice-free summers in the coming decades. The research is published in the journal Geophysical Research Letters. The scientists considered the future of Arctic sea-ice cover in scenarios with high future CO2 emissions and little climate protection – as expected, Arctic sea ice disappeared quickly in summer in these simulations. But the study also found the Arctic summer sea ice also disappears “occasionally” if CO2 emissions are rapidly reduced. Dirk Notz, who leads the sea-ice research group at University of Hamburg, said: “If we reduce global emissions rapidly and substantially, and thus keep global warming below 2C relative to preindustrial levels, Arctic sea ice will nevertheless likely disappear occasionally in summer even before 2050. This really surprised...
Deadly virus spreads among marine mammals as Arctic ice melts

Deadly virus spreads among marine mammals as Arctic ice melts

SOURCE: National Geographic DATE: November 7, 2019 SNIP: When sea otters in Alaska were diagnosed with phocine distemper virus (PDV) in 2004, scientists were confused. The pathogen in the Morbillivirus genus that contains viruses like measles had then only been found in Europe and on the eastern coast of North America. “We didn’t understand how a virus from the Atlantic ended up in these sea otters. It’s not a species that ranges widely,” says Tracey Goldstein, a scientist at the University of California Davis who investigates how pathogens move through marine ecosystems. Using 15 years of data from 2001 to 2016, Goldstein and her research team were able to see upticks in PDV that corresponded with declines in Arctic sea ice. This new range for the otters likely allowed infected animals to move west, into new territories where the virus had not appeared before. The results of the study, published today in the journal Scientific Reports, shows how climate change may be opening up new pathways for disease to spread. Phocine distemper virus was first detected in 1988 in northern Europe, where an estimated 18,000 seals died, most of them harbor seals. A similar outbreak occurred in 2002. It’s unclear where PDV originated. Some research has suggested it originated in the Arctic, but variations of distemper are found in dozens of animals. Local vets regularly vaccinate pet dogs against the canine version. And in seals, as with dogs, symptoms of the virus include difficulty breathing, discharge from the nose and eyes, fever, and in marine mammals, erratic swimming. To construct when and where PDV spread from northern Europe to...
As Bering Sea ice melts, Alaskans, scientists and Seattle’s fishing fleet witness changes ‘on a massive scale’

As Bering Sea ice melts, Alaskans, scientists and Seattle’s fishing fleet witness changes ‘on a massive scale’

SOURCE: Seattle Times DATE: September 15, 2019 SNIP: For two years, the Bering Sea has been largely without winter ice, a development scientists modeling the warming impacts of greenhouse-gas pollution from fossil fuels once forecast would not occur until 2050. This ice provided a giant platform for growing algae at the base of the food chain, and has been a significant contributor to the remarkable productivity of a body of water, stretching from Alaska to northeast Russia, that sustains some of the biggest fisheries on the planet. Much of U.S. seafood – ranging from fish sticks to king crab legs – comes from the Bering Sea, which generates income for an arc of communities that reaches from Savoonga to Seattle, where many of the boats that catch and process this bounty are home-ported. For Native people such as Akeya, who is Yup’ik, the ice also has shaped their culture, helping them to hunt the walruses, whales, seals and other marine life that have long formed a crucial part of their diet. Researchers now are uncertain when and to what extent the ice may return, and have scrambled to better understand the consequences of back-to-back years of its loss. This summer, the pace of change also quickened on shore as a record-shattering heat wave contributed to the deaths of salmon before they could spawn, to wildfires that shrouded the city of Anchorage in smoke, and to the further melting of permafrost, which causes ground to shift and can create problems for buildings and roads. Offshore, temperatures in some spots at the bottom of the northern Bering Sea this summer measured...
‘Precipitous’ fall in Antarctic sea ice since 2014 revealed

‘Precipitous’ fall in Antarctic sea ice since 2014 revealed

SOURCE: The Guardian DATE: July 2, 2019 SNIP: The vast expanse of sea ice around Antarctica has suffered a “precipitous” fall since 2014, satellite data shows, and fell at a faster rate than seen in the Arctic. The plunge in the average annual extent means Antarctica lost as much sea ice in four years as the Arctic lost in 34 years. The cause of the sharp Antarctic losses is as yet unknown and only time will tell whether the ice recovers or continues to decline. But researchers said it showed ice could disappear much more rapidly than previously thought. Unlike the melting of ice sheets on land, sea ice melting does not raise sea level. But losing bright white sea ice means the sun’s heat is instead absorbed by dark ocean waters, leading to a vicious circle of heating. Sea ice spreads over enormous areas and has major impacts on the global climate system, with losses in the Arctic strongly linked to extreme weather at lower latitudes, such as heatwaves in Europe. Antarctic sea ice had been slowly increasing during the 40 years of measurements and reached a record maximum in 2014. But since then sea ice extent has nosedived, reaching a record low in 2017. “There has been a huge decrease,” said Claire Parkinson, at Nasa’s Goddard Space Flight Center in the US. In her study, published in the journal Proceedings of the National Academy of Sciences, she called the decline precipitous and a dramatic reversal. “The Arctic has become a poster child for global warming,” Parkinson said, but the recent sea ice falls in Antarctica have been...