Wednesday, 14 December 2016

'The Arctic Is Unraveling'


There have been headlines across the media today, even the denialist Daily Telegraph

'The Arctic Is Unraveling,' Scientists Conclude After Latest Sobering Climate Report
Unprecedented warming has sent the Arctic into uncharted territory, says latest NOAA report, as its science faces potential hostility from the Trump administration.

BY BOB BERWYN, INSIDECLIMATE NEWS






13 December, 2016The ill winds of climate change are irrevocably reshaping the Arctic, including massive declines in  sea ice and snow and a record-late start to sea ice formation this fall. Those were the sobering conclusions of the 2016 Arctic Report Card released Tuesday.

The report card is sponsored by the  National Oceanic and Atmospheric Administration (NOAA) and co-authored by more than 50 scientists from Asia, North America and Europe. The data shows that the Arctic is warming at double the rate of the global average temperature. Between October 2015 and September 2016, temperatures over Arctic land areas were 2.0 degrees Celsius above the 1981-­2010 baseline, the warmest on record going back to 1900.

The report, released at the American Geophysical Union meeting in San Francisco, clearly links the Arctic heatwave to a record-late start to formation of sea ice this fall, and to record high and low seasonal snow cover extent in the Northern Hemisphere. If the extreme warmth recorded in the Arctic this fall persists for the next few years, it may signal a completely new climate in the region, scientists said.

Jeremy Mathis, director of NOAA's Arctic Research Program, said the report highlights the clear and pronounced global warming signal in the Arctic and its effects cascading throughout the environment, like the spread of parasitic diseases in Arctic animals.

"We've seen a year in 2016 like we've never seen before ... with clear acceleration of many global warming signals. The Arctic was whispering change. Now it's not whispering. It's speaking, it's shouting change, and the changes are large," said co-author Donald Perovich, who studies Arctic climate at Dartmouth College.

Sustained observations of the Arctic is crucial to making science-based policy decisions, he added, a goal threatened by the inclusion of numerous climate deniers in President-elect Donald Trump's cabinet. This week, Trump's transition team posted a new "Energy Independence" websitethat repeats his previous intentions to open up vast areas for fossil fuel development and to scrap existing climate action plans.

Arctic ice doesn't care about politics, and what happens in the region now is critically important to the U.S., said Rafe Pomerance, chair of Arctic 21 and a member of the Polar Research Board of the National Academies of Sciences, Engineering and Medicine.

"What kind of Arctic do we want to have? It has to be one that maintains the stability of the climate system," he said. "The melting of Greenland is going to put an enormous hit on real estate values. The fate of Greenland is the fate of Miami. It's in the U.S. national interest to stop Greenland's ice sheet from melting. How are we going to bring it to a halt?"

The scientific report stands in stark contrast to the incoming administration's apparent intention to foster more fossil fuel development, he said.
"This is a byproduct of the poison of denialism, a political issue that has taken hold so deeply so that this is the kind of stuff that can be contemplated," he said. "Evidence doesn't mean anything, science doesn't seem to mean anything. They ought to take what's going on in the Arctic really seriously. This is a crisis. The Arctic is unraveling."

The report card underscores nearly a year of unusual conditions, said Lars Kaleschke, an Arctic researcher at the University of Hamburg who was not among the report's authors. Extremely warm air temperatures last January and February led to the smallest maximum winter sea ice extent on record, equaling the record set in  2015. And the return of extreme warmth in November led to a short period of ice retreat at a time when it's usually growing fast.

Kaleschke said he's become concerned by reports that the incoming U.S. administration may cut NASA's Earth observation budget, which includes many programs critical to understanding Arctic global warming changes.

"That would be a huge loss for the climate research community," he said. Those programs are critical to efforts to understand rapid Arctic changes.NASA's airborne IceBridge program, for example, helps confirm ice thickness measurements made by the European Space Agency's CryoSat program.
Kaleschke said Trump appears to have a clear anti-science attitude that will affect the world's ability to respond to climate change.

The  global warming signal was particularly evident in Greenland in 2016, said Marco Tedesco, a climate researcher with Columbia University's Lamont-Doherty Earth Observatory who was involved in the report.

"The Greenland Ice Sheet continued to lose mass in 2016. The melt onset was the second earliest and the melt season was 30 to 40 days longer than average in the northeast, he said. Spring snow cover extent in Greenland and other parts of the Arctic reached new record lows in spring and there's new evidence that snow depth is also decreasing, which would be a precursor to even earlier and faster melting."

Arctic permafrost is also releasing more greenhouse gases in the winter than plants can take up in the summer, making the Arctic a net source of heat-trapping pollution, he dded.

Snow cover on land helps cool the entire Northern Hemisphere climate system, insulates soil and regulates the water cycle through the seasons.

Highlighting the the recent changes in the Arctic is even more important in light of the current political context, said University of Sheffield geographer Edward Hanna, who co-authored the report's chapter on air surface temperatures.

Air temperatures across the Arctic between January and March 2016 soared past previous record highs, with some locations reporting anomalies of more than 8 degrees Celsius. In recent decades, there have been more frequent surges of warm air from mid-latitudes far north into the Arctic. That lends support to the emerging hypothesis that the Arctic meltdown is changing the path of the jet stream, possibly leading to more sustained extreme weather events in the Northern Hemisphere, Hanna said.

The steady trend toward thinner, younger ice in the Arctic is also notable, suggesting the meltdown is irreversible.

"It's hard to see how the summer sea ice will survive," he concluded.


Getty images

Persistent warming trend and loss of sea ice are triggering extensive Arctic changes.

Observations in 2016 showed a continuation of long-term Arctic warming trends which reveals the interdependency of physical and biological Arctic systems, contributing to a growing recognition that the Arctic is an integral part of the globe, and increasing the need for comprehensive communication of Arctic change to diverse user audiences.


Highlights

  • The average surface air temperature for the year ending September 2016 is by far the highest since 1900, and new monthly record highs were recorded for January, February, October and November 2016.
  • After only modest changes from 2013-2015, minimum sea ice extent at the end of summer 2016 tied with 2007 for the second lowest in the satellite record, which started in 1979.
  • Spring snow cover extent in the North American Arctic was the lowest in the satellite record, which started in 1967.
  • In 37 years of Greenland ice sheet observations, only one year had earlier onset of spring melting than 2016.
  • The Arctic Ocean is especially prone to ocean acidification, due to water temperatures that are colder than those further south.  The short Arctic food chain leaves Arctic marine ecosystems vulnerable to ocean acidification events.
  • Thawing permafrost releases carbon into the atmosphere, whereas greening tundra absorbs atmospheric carbon.  Overall, tundra is presently releasing net carbon into the atmosphere.
  • Small Arctic mammals, such as shrews, and their parasites, serve as indicators for present and historical environmental variability. Newly acquired parasites indicate northward sifts of sub-Arctic species and increases in Arctic biodiversity



"Truly wonderful news. Maybe we won't have to leave the UK to enjoy warm weather from spring through autumn, and we'll all save a fortune on our heating bill"


---Rod Large (comment)

Arctic temperatures have hit levels last seen a ridiculously long time ago

The word glacial should be redefined to mean 'rapidly diminishing' rather than slow, researchers say, as the pace of change in the Arctic begins to outstrip their ability to understand what's happening


13 December, 2016

Parts of the Arctic were an average of 11 degrees Celsius warmer than they were in the late 20th century as the region experienced “extreme record temperature anomalies”, the US National Oceanic and Atmospheric Administration (NOAA) has said.

Scientists who produced the annual Arctic Report Card warned the situation was changing so quickly it was “outpacing our ability to understand and explain” what they were witnessing.

They even suggested the word glacial could no longer be used to mean a slow pace and should be redefined to refer to something that was “rapidly diminishing”.

The report found the average annual air temperature over land areas was the “highest in the observational record” at 3.5C above 1900. Sea ice levels also fell to the lowest since satellite records began in 1979.

These are both likely to indicate the warmest Arctic weather for tens of thousands of years.

The Arctic has a considerable effect on the northern hemisphere’s weather with some experts saying the rapid warming of the region – more than twice the global average – could produce “catastrophic” extreme weather events for much of the planet.

As climate science denier Donald Trump prepares to move into the White House next month, the NOAA report said the situation was “increasing the pressure” to communicate the importance of the “scientific observations”.

Jeremy Mathis, director of NOAA’s Arctic research programme, said: “Rarely have we seen the Arctic show a clearer, stronger or more pronounced signal of persistent warming and its cascading effects on the environment than this year.

While the science is becoming clearer, we need to improve and extend sustained observations of the Arctic that can inform sound decisions on environmental health and food security as well as emerging opportunities for commerce.”

Arctic temperatures continue to increase at double the rate of the global temperature increase,” it added.

Amid the 3.5C increase on land, there were some particularly “extreme record warm temperature anomalies”.

The warmest temperature anomalies were centred on Alaska, Svalbard in the Atlantic sector and the central Arctic,” the report said.

In the Spitsbergen area, the three-month winter mean temperatures were 8 to 11C above the 1961-90 average.”

The levels of ice on both land and sea have been shrinking dramatically.

For Arctic researchers, communicating the impacts of our discoveries has taken on an unprecedented urgency in the face of environmental change that – in many instances – is outpacing our ability to understand and explain the changes we are witnessing,” the report said.

Accustomed to advancing our scientific disciplines at what is often called a ‘glacial’ pace, we recognise that glaciers are not so slow anymore.

Before long, we may need to redefine ‘glacial’ to mean something that is rapidly diminishing or employ a different adjective.”

Sea ice grows and shrinks with the seasons hitting a low point in October or November. This year the sea ice minimum was the lowest since satellite records began in 1979.

Scientists expect the Arctic to be effectively free of sea ice for the first time in about 100,000 years within the next few decades, but some have argued this could happen much sooner.

Sea ice extent has decreasing trends in all months and virtually all regions, the exception being the Bering Sea during winter,” the NOAA report said.

It said the changes in the Arctic could lead to a number of “trillion dollar impacts – both positive and negative”.

On one hand, new shipping lanes are already opening up and, ironically, less ice also means oil exploration is not as risky.

But, on the other, the warming Arctic could have “major implications” for our economic welfare and life as we know it, the report said.

As is amply demonstrated in each annual instalment of the Arctic Report Card, the domain is collectively experiencing rapid and amplified signatures of global climate change,” it said.

The Arctic system’s response to this broader forcing has become a central research topic, given its potential as a critical throttle on future planetary dynamics.

Changes are already impacting life systems, cultures and economic prosperity and continued change is expected to bear major implications far outside the region.”

Professor Peter Wadhams, the head of the Polar Ocean Physics Group at Cambridge University and author of the book, A Farewell to Ice, warned the loss of snow cover, which has hit a record low, and sea ice was speeding up global warming.

"I calculate that between them they are causing the effective heating of the planet to be 50 per cent higher than would be caused by the added greenhouse gases alone – entirely due to snow and ice retreat," he told the Independent in an email.

Professor Wadhams suggested that Arctic sea ice was "well and truly set on a collapse".

And this, he warned, could have a dramatic and sudden effect on global temperatures.

"The warm sea water melts the offshore permafrost, which releases methane trapped in the sediments below," Professor Wadhams said.

"There is potential for a catastrophic methane pulse which cause immediate warming of up to 0.6C, according some calculations which we did in [the journal] Nature a couple of years back."


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