In May this year I attended a climate meeting in Dushanbe, the capital of Tajikistan, on exploring ways of preserving the world’s glaciers in the face of anthropogenic climate change. The climate backdrop to this meeting was that the current rate of global warming has exceeded that seen in human history and recent warming has now breached 1.5° C above pre-industrial temperatures. On current emission pathways we will reach between 1.9 and 3.7 ° C warming by 2100. International Mountain Day on 11th December will reflect on this.
The location of the meeting was telling; while climate change is melting the vast majority of the world’s glaciers, those in the mountains of Central Asia are particularly exposed to warming now and in the future. Hundreds of millions of people rely on the region’s glaciers to regulate their water supplies, maintain irrigation and provide ecosystem services. Climate warming and glacier melt is therefore an enormous problem, and this is exacerbated by the influence of geography. Being in the middle of Asia, the glaciers are far from the moderating influence of the oceans; as a result even modest global temperature rises are multiplied in the Northern Hemisphere land masses so that warming in Central Asia is likely to be far above the global mean surface temperature rises projected by the end of the century. This is supported by recent climate modelling for regions of central Asia which showed that the wider region might expect temperatures to rise by 5° C by the end of the century. Such a temperature rise and the shifts in precipitation associated with this will devastate the glaciers in the high mountains, with perhaps only 10% of current glacier mass remaining after this time. Widespread glacier and permafrost melting will have enormous consequences for economic, social, cultural and environmental systems; and the political consequences of this are only now being seriously considered.
Our understanding of how glaciers melted in the past also shows that the mountains undergo a period of rapid transition in response, with decades of increased rockfalls, glacial lake outburst floods (GLOFs) and ice avalanches following glacier retreat. Sustainable development of mountain regions therefore needs to not only consider the impact of melting glaciers on future water supplies, but also the impact of extreme geological events like GLOFs on mountain infrastructure and people. It is ironic that over recent years glacier hazards have severely damaged Hydro-Electric Power schemes in high Himalayan mountain valleys; precisely those infrastructure schemes that aim to move societies towards a more sustainable energy future. Meeting Sustainable Development Goals will be one of the great challenges for the remainder of this century.
Professor of Climate and Environmental Change at the University of Exeter in the UK. He has 35 years of experience working in the high mountains of South America and Himalaya on climate change and glacier response. He also advises the UK Government on climate change impacts and is the director and founder of Climate Change Risk Management (www.ccrm.co.uk) which advises governments and NGOs around the world on climate change.