An international team of scientists, including experts from Newcastle University, is calling for urgent and rigorous monitoring of temperature patterns in mountain regions after finding evidence that high elevations could be warming faster than previously thought.

The research team says that without substantially better information, we risk underestimating the severity of a number of already looming problems, including water shortages and the possible extinction of some alpine flora and fauna.

The research is published today in the journal Nature Climate Change.

Co-authors of the research, Prof. Hayley Fowler and Dr. Nathan Forsythe, from Newcastle University’s School of Civil Engineering and Geosciences, have been working on climate change in the Himalayas for over a decade. Prof Fowler said: “Changes to climate, glaciers and snow cover in the high mountains of Asia are of vital importance for water supplies to a fifth of the world’s population, so understanding past changes are key to understanding what might happen in the future. This paper highlights the need for additional monitoring in high elevation locations worldwide, but particularly in the less researched Himalayan region.”

Lead author, Dr Nick Pepin of the University of Portsmouth, said: “Most current predictions are based on incomplete and imperfect data, but if we are right and mountains are warming more rapidly than other environments, the social and economic consequences could be serious, and we could see much more dramatic changes much sooner than previously thought.”

The most striking evidence that mountain regions are warming more rapidly than surrounding regions comes from the Tibetan plateau. Here temperatures have risen steadily over the past 50 years and the rate of change is speeding up. But masked by this general climate warming are pronounced differences at different elevations. For example, over the past 20 years temperatures above 4,000 metres have warmed nearly 75 per cent faster than temperatures in areas below 2,000 metres.  

The team of scientists came together as part of the Mountain Research Initiative, a mountain global change research effort funded by the Swiss National Foundation. The team includes scientists from the UK, US, Switzerland, Canada, Ecuador, Pakistan, China, Italy, Austria and Kazakhstan. Between them, they have studied data on mountain temperatures worldwide collected over the past 60-70 years.

Among the reasons the researchers examined for faster rates of temperature increase in mountain regions are:

• Loss of snow and ice, leading to more exposed land surface at high elevation warming up faster in the sun
• Increasing release of heat in the high atmosphere. A warmer atmosphere holds more moisture, which, when condensing as clouds at high elevation, releases more heat to the mountain environment
• Aerosol pollutants at low elevations, including haze, dust and smoke, reduces  warming at those elevations, thus increasing the difference in rates of warming between low and high elevations
• Dust and soot deposited on the surface at high elevations causes more incoming sunlight to be converted to heat

The complex combination of any or all of the above factors in different regions and at different times of the year.

Records of weather patterns at high altitudes are ‘extremely sparse’, the researchers found. The density of weather stations above 4,500 m is roughly one-tenth that in areas below that elevation. Long-term data, crucial for detecting patterns, doesn’t yet exist above 5,000 m anywhere in the world. The longest observations above this elevation are 10 years on the summit of Kilimanjaro.

Improved observations, satellite-based remote sensing and climate model simulations are all needed to gain a true picture of warming in mountain regions, the researchers say. Much of that requires international agreement and collaboration – and funding.

The world’s highest mountain, Mt Everest, stands at 8,848 m. More than 250 other mountains, including Mt Elbrus in Russia, Mt Denali in Alaska, Mt Aconcagua in Argentina and Mt Kilimanjaro in Africa, also all top the 5,000 m mark. Ben Nevis, in Scotland, is the UK’s highest mountain, standing at 1,344 m.

Watch a video of Prof Fowler and Dr Forsythe talking about the study. 

Picture courtesy of Prof Hayley Fowler.

published on: 23 April 2015