A rapid climate shift under way in the Barents Sea could spread to other Arctic regions, scientists warn says, Roger Harrabin for BBC.
The Barents Sea is said to be at a tipping point, changing from an Arctic climate to an Atlantic climate as the water gets warmer.
A conference in Norway heard that the Kara sea and the Laptev Sea – both further to the east – are likely to become the new Arctic frontier.
What will be the effect?
The scientists warn that it will affect ecosystems. It may also impact on global weather patterns, although there’s no agreement on that.
They’re concerned because the north Barents Sea has been governed by an Arctic climate since the end of the last Ice Age 12,000 years ago.
Retaining Fresh water cap
The Arctic Ocean has a cold, fresh surface layer which acts as a cap on a layer of warm saltier Atlantic water beneath.
But now in the Barents Sea there’s not enough freshwater-rich sea ice flowing from the high Arctic to maintain the freshwater cap. And this allows warm, salty Atlantic water to rise to the surface.
In what’s known as a feedback loop: the more the layers mix, the warmer the surface gets. And the warmer the surface gets, the more the waters mix.
So it’s now only a matter of time, the researchers say, before this section of the Arctic effectively becomes part of the Atlantic. It could happen in as little as a decade, they warn.
Change may be irreversible
Dr Sigrid Lind from the Institute of Marine Research and Bjerknes Centre for Climate Research in Norway, told the conference that if the sea stratification breaks down completely, the change may be irreversible.
“Large sea ice inflows of several consecutive years would probably be needed to rebuild the freshwater reservoir ones its gone- and that’s not likely given global warming and strong Arctic sea ice loss,” she told BBC News.
A new polar frontier?
Dr. Lind said the shift was so rapid that the whole Barents Sea could be completely sea ice-free within a few decades – possibly even a decade.
Then a new polar frontier region would probably develop further east, in the Kara Sea or Laptev Sea.
Last ice Age scenario repeated?
She explained this to be probably the first modern example of a rapid climate shift event – a part of the Arctic domain is shifting over to the Atlantic climate regime. Also added, this sort of shift happened in the Nordic Seas during the last Ice Age – and when it happened it changed very fast.
“This shows that the Arctic is responding to the one-degree of global warming that we have today by shrinking and losing its outer part to the Atlantic domain. That’s alarming.”
Human impact on the planet
Dr Jeremy Wilkinson from the British Antarctic Survey (BAS) told BBC News that the new findings on stratification and freshwater were vital for understanding the future of the Arctic.
Other scientists said different factors may be significant too, like a change in wind patterns that appears to be pushing sea ice away from the Barents region.
The changes could affect weather patterns as far away as East Asia, and may have an effect on the jet stream, which influences so much of the UK’s weather patterns. Scientists haven’t reached agreement on this yet.
Another puzzle is that freshwater in the western Arctic seems to be increasing as it diminishes in the eastern Arctic. Scientists are still struggling to fathom the complexities of human impact on the planet.
Disclaimer: This video is intended for informational purpose only. This may not be construed as a news item or advice of any sort. Please consult the experts in that field for the authenticity of the presentations.
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