Warming in mountains could be 50 pc faster compared to global average, says study

Warming at high elevations in mountains, including the Himalayas, could be about 50 per cent faster than the global average since 1950, which can have potentially devastating consequences for over a billion people depending on the regions, according to a study.
Globally, compared to lowlands, mountains were estimated to experience an enhanced warming of 0.21 degrees Celsius per century during 1980-2020, an enhanced drying of 11.5 millimetres per century and accelerated melting of snow of 25.6 millimetres per century, findings published in the journal Nature Reviews Earth and Environment show.
An international team of researchers, led by those from the UK’s University of Portsmouth, looked at ‘elevation-dependent climate change’ – a phenomenon where environmental changes can accelerate at higher altitudes. Factors driving it include surface albedo (radiation reflected by a surface compared to what falls on it), specific humidity and aerosol levels in the air.
“Mountains share many characteristics with Arctic regions and are experiencing similarly rapid changes,” lead researcher Nick Pepin from the University of Portsmouth’s Institute of the Earth and Environment said.
“This is because both environments are losing snow and ice rapidly and are seeing profound changes in ecosystems. What’s less well known is that as you go higher into the mountains, the rate of climate change can become even more intense,” Pepin said.
However, it is not as simple as the highest mountains being the most sensitive to elevation-dependent climate change, “because although on average climate change is accelerating at higher elevations, there is lots of regional variation,” the lead researcher said in an email, responding to PTI’s question about which mountain range might be the most vulnerable.
“In lots of cases, loss of snow is an important driving factor so it is those intermediate elevations where the snow has receded (imagine the snowline is going up) that are changing most quickly,” he said.
Aerosols released from lowland areas – for example, in India and China – which can make their way up onto the snow and ice and cause accelerated melt and loss, is another important factor influencing climate change in mountain regions, he added.
The team, which also included researchers from India’s Uttaranchal and Jawaharlal Nehru universities, analysed data from global datasets and reviewed evidence from case studies from mountain ranges such as the Alps, Tibetan Plateau and High-Mountains Asia.
“On a global scale, differences between mountain and lowland trends for temperature, precipitation and snowfall are 0.21 degrees Celsius per century (enhanced mountain warming), (minus) 11.5 millimetres per century (enhanced mountain drying) and (minus) 25.6 millimetres per century (enhanced mountain snow loss), respectively, for 1980-2020,” the authors wrote.
“Such positive elevation-dependent warming (EDW) is evident at historical and longer timescales, and despite much variation according to time of day, season and location, the mean warming at high elevations is nearly 50 per cent faster than the global mean since 1950,” the team said. (PTI)