The Phnom Penh Post

Study: Arctic’s warming drives ‘broad change’ in environmen­t

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GLOBAL warming is heating the Arctic at a record pace, driving broad environmen­tal changes across the planet, including extreme storms in the US and Europe, a major US scientific report said on Tuesday.

Persistent heat records have assaulted t he fragile Arctic for each of the past five years – a record-long warming strea k, said the 2018 Arctic Report Card, released by t he Nat iona l Oceanic and Atmospheri­c Administra­tion (NOA A).

The mounting heat in the north is upsetting typical weather patterns, a trend that “coincides” with severe winter storms in the eastern US and an extreme cold snap in Europe in March, it said.

“Continued warming of the Arctic atmosphere and ocean are driv ing broad change in the env ironmental system in predicted and, a lso, unexpected ways,” warned the report.

“New and rapidly emerging threats are ta k ing form and highlighti­ng the level of uncertaint y i n t he breadth of env ironmental change that is to come.”

Emily Osborne, programme manager of NOAA’s Arctic Research Programme, told reporters that the Arctic “is experienci­ng the most unpreceden­ted transition in human history.”

The report was released at the American Geophysica­l Union’s annual conference in Washington, just weeks after another damning climate assessment by federal scientists which US President Donald Trump dismissed, saying he did not “believe” it.

Asked by reporters if he had personally briefed Trump on the latest Arctic findings, NOAA acting administra­tor Timothy Gallaudet said he had not, but he insisted that NOAA has the White House’s support when it comes to scientific research.

Temperatur­e record

Arctic air temperatur­es for the past five years, from 2014 to this year, “have exceeded all previous records since 1900”, when record-keeping began, said the peer-reviewed report compiled by 81 scientists working for government­s and academia in 12 nations.

This warming trend “is unlike any other period on record”, it said.

During the latest period studied, October last year through September, annual average temperatur­e in the Arctic was 1.7 Celsius higher than the 1981–2010 average.

“The year 2018 was the second warmest year on record in the Arctic since 1900 [after 2016],” it said.

The Arctic also saw the secondlowe­st overall sea-ice coverage and the lowest recorded winter ice in the Bering Sea.

Another key measure of ice cover is its age, and t he old, t hick k ind is rapidly disappeari­ng across t he Arctic.

Last year, old ice made up less than one per cent of the ice pack.

Over t he past 33 years, ver y old Arctic ice has declined by 95 per cent.

The Arctic continues to heat up at twice the rate of the rest of the planet, but the effects are far from isolated, and are now spilling over into the mid-latitudes.

That’s because a warmer Arctic reduces the north-south temperatur­e difference, which prov ides the main f uel for t he polar jet stream, or a river of strong wind, at levels where jet aircraft fly, NOA A said.

In this warming environmen­t, the jet stream has become wavier, a pattern that “allows warm air to penetrate farther north and cold air to plunge farther south, compared to when the jet is strong and relatively straight,” said the report.

Scientist now see evidence that this changing jet stream may be sparking extreme storms.

Examples include “the heat wave at the North Pole in autumn last year, a swarm of severe winter storms in the eastern US this year, and the extreme cold outbreak in Europe in March known as the ‘Beast from the East’”.

Reindeer, marine life

Meanwhile, warmer Arctic temperatur­es are wreaking havoc on the Arctic ecosystem, decimating reindeer and caribou population­s, allowing harmful algae blooms to move northward and sickening marine life, said the report, now in its 13th year.

“Considerab­le concentrat­ions of a lga l tox ins have been found in the tissues of Arctic cla ms, sea ls, walrus, and whales and other marine organisms,” it said.

Even though melting ice has freed up more land for grazing, herds of caribou and wild reindeer across the Arctic tundra have declined by 56 per cent over the last two decades, cutting population­s from 4.7 million to 2.1 million.

“The long-term warming trend may be ta k ing a toll on some of the Arctic’s most majestic animals,” said Howard Epstein, professor of env ironmental sciences at t he Universit y of Virginia.

Scientists attribute the decline to increased frequency of drought, which affects quality of the tundra, and longer and hotter summers which can lead to more parasites.

Another new focus of the report involved the emerging threat of marine microplast­ics, which scientists have discovered are accumulati­ng in the Arctic at higher concentrat­ions than anywhere else in the world.

“This pollution – from plastics produced and discarded in more populated areas of the world – is likely traveling with ocean currents to the Arctic,” said Karen Frey, professor of geography at Clark University.

Microplast­ic contaminat­ion has increased over the last decade, and is a concern because seabirds and marine life can ingest debris, sickening them and interferin­g with a key food and income source for people who consume them, she said.

 ?? MARIO TAMA/AFP ?? Nasa’s Operation IceBridge research aircraft captures the ice fields of Ellesmere Island in Canada. Global warming is heating the Arctic at a record pace, a major US scientific report said on Tuesday.
MARIO TAMA/AFP Nasa’s Operation IceBridge research aircraft captures the ice fields of Ellesmere Island in Canada. Global warming is heating the Arctic at a record pace, a major US scientific report said on Tuesday.

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