Slight Arctic Warming Could Trigger Abrupt Permafrost Collapse – Study


A few degrees of warming in the Arctic could trigger an abrupt thaw of the permafrost that makes up two-thirds of Russia’s landmass and a subsequent climate change feedback loop, according to a new study based on ancient warming episodes.

Three of the region’s largest warming events in the past 27,000 years coincided with rapidly thawing and collapsing permafrost, said the study published Friday in the Science Advances journal. Its findings are based on an analysis of 8-meter sediment cores retrieved from the bottom of the Arctic Ocean off of Eastern Siberia by a team of Russian, Swedish and U.S. scientists in 2014. 

This demonstrates that Arctic warming by only a few degrees may suffice to abruptly activate large-scale permafrost thawing,” the study’s authors wrote. 

The warming works like “a sensitive trigger for a threshold-like permafrost climate change feedback,” they added. 

Scientists have long argued that climate change could trigger a feedback loop in which melting permafrost releases greenhouse gases like carbon and methane into the atmosphere, further accelerating global warming and permafrost melt.

Our study indeed suggests that abrupt permafrost thawing represents a tipping point in the climate system,” lead author Jannik Martens told the Inside Climate News website.

When that tipping point will arrive is still an open question, he added.

An Intergovernmental Panel on Climate Change (IPCC) report last year said Russia’s permafrost is expected to thaw at an accelerating rate between now and 2100.  

The IPCC report predicts that 70% of surface-level permafrost could thaw by 2100 if greenhouse gas emissions continue to rise, shifting the world’s “permafrost border” increasingly northward. 

More than 65% of Russia’s territory is located in the planet’s frozen cryosphere. The country is the world’s fourth-largest emitter of greenhouse gases.

The latest study’s co-author Örjan Gustafsson stressed that greenhouse gas emissions from both thawing permafrost and man-made sources will inevitably lead to “dangerous thresholds.”

The only way to limit permafrost-related greenhouse gas releases is to mitigate climate warming by lowering anthropogenic greenhouse gas emissions,” he told Scientific American. 



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Environment Canada warns of ‘abrupt transition to fall’ in three provinces this weekend


TORONTO —
Environment Canada has issued special weather statements for three provinces warning of an “abrupt transition to fall” over the Labour Day long weekend.

The special weather statements apply to Alberta, Saskatchewan and Manitoba and will remain in effect until Tuesday morning.

Environment Canada said the early fall weather is being brought on by an Alberta Clipper — a low-pressure area weather system — moving across the eastern Prairies. The clipper is expected to bring showers, gusty winds and cooler daytime temperatures to the three provinces starting Sunday.

A cold air mass will slide south in the wake of the low-pressure system covering most of Alberta by Monday morning with overnight temperatures expected to fall below 0 C.

Snowfall is forecasted to remain in and near the province’s mountain parks but Environment Canada says there is a chance of mixed precipitation for areas along the lower elevations of the Foothills, including Calgary.

Five to 30 millimetres of rain is expected by Monday evening and frost will likely cover most of Alberta by Tuesday morning, specifically in the southern and central regions.

Up to 5 centimetres of snow is expected along higher elevated regions in the Foothills, with up to 10 centimetres possible in areas with lower elevation.

However, the weather agency warned that snowfall totals are “very uncertain” as the warm ground and the “confidence in the timing of the change over to snow” is not high. Daytime heating on Monday is also expected to limit the snowfall accumulation.

In Saskatchewan, residents should prepare for wind gusts of 50 to 80 km/h from the northwest on Sunday with the strongest gusts hitting the southeastern region.

The Clipper is expected to move over Saskatchewan Monday and Tuesday morning, bringing with it the possibility of widespread frost in a number of locations in the southern area of the province.

Manitobans can expect gusts of wind up to 80 km/h moving from the northwest to the southwest on Sunday. A wind warning is currently in effect for the Red River Valley with gusts up to 90 km/h in the forecast.

The Clipper will entrench itself over Manitoba by Tuesday morning, according to Environment Canada.

Widespread frost is also possible for a number of regions in southwestern Manitoba on Tuesday. Environment Canada says the risk of frost may linger over the Red River Valley and other southern parts of the province until Wednesday morning.

Frost advisories are expected to be issued for Saskatchewan and Manitoba with Environment Canada’s Monday afternoon forecasts.

Following the abrupt change in weather conditions across the Prairies, a strong ridge of high pressure will additionally build over northern British Columbia and spread southwards on Sunday night.

While temperature drops and precipitation is not expected, Environment Canada is warning B.C. residents to anticipate northerly wind gusts upwards of 60 km/h throughout many of the valleys in the southern interior beginning after midnight.

Environment Canada says the winds could cause an increased risk of damage to trees.

The winds will likely peak Monday morning in B.C. however, the weather agency said gusty conditions may prevail throughout the day.



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Trump news – live: White House silent on abrupt decision to cancel golf trip as growing number of states reimpose coronavirus lockdown measures


EPA

A US court has ordered the release of more than 100 children held with their parents in immigration jails and denounced the Trump administration‘s prolonged detention of families during the coronavirus pandemic.

District Judge Dolly Gee’s order applies to children held for more than 20 days at three family detention centres in Texas and Pennsylvania operated by US Immigration and Customs Enforcement (ICE). Some have been detained since last year.

Citing the recent spread of the virus in two of the three facilities, Judge Gee set a deadline of 17 July for children to either be released with their parents or sent to family sponsors.

It decision came as Donald Trump cancelled a planned weekend visit to his golf resort in Bedminster, New Jersey, and said he was staying in Washington “to make sure LAW & ORDER is enforced”.

“The arsonists, anarchists, looters, and agitators have been largely stopped,” Mr Trump wrote on Twitter late on Friday. “I am doing what is necessary to keep our communities safe – and these people will be brought to Justice!”

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