Monday, September 25, 2017

Cold Region 'Tipping Point' Now Inevitable

Intense soil frost churning at Kilpisjärvi, northwestern Finland, at 800 meters above sea level. (Photo Credit: Juha Aalto) Click to Enlarge.
The decline of cold regions called periglacial zones is now inevitable due to climate change, researchers say.

Periglacial zones, where there is often a layer of frozen ground known as permafrost, make up about a quarter of the Earth's land surface and are mostly found in the far north and south, and at high altitudes.

Scientists from the universities of Exeter and Helsinki and the Finnish Meteorological Institute examined natural processes caused by frost and snow which take place in these zones.

Their findings suggest that - even with optimistic estimates of future carbon emissions - areas covered by periglacial zones will reduce dramatically by 2050, and they will "almost disappear" by 2100.

This would have a major impact on landscapes and biodiversity, and could trigger climate "feedbacks" - processes that can amplify or diminish the effects of climate change.

"The results suggest that profound changes can be expected in current periglacial zones regardless of climate change mitigation policies," said Dr Juha Aalto, of the University of Helsinki and the Finnish Meteorological Institute.

"Unfortunately, it seems that many of the frost-driven processes we studied are already at the margin of the climate in which they can exist."

The scientists studied four processes which take place in periglacial zones, including snow accumulation sites and "frost churning" - which refers to mixing of materials caused by freezing and thawing.

"Our results forecast a future tipping point in the operation of these processes, and predict fundamental changes in ground conditions and related atmospheric feedbacks," Dr Aalto added.

Read more at Cold Region 'Tipping Point' Now Inevitable

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