What’s so special about mountains?

In 2016, two unusual and deadly glacier avalanches occurred in Tibet’s Aru Mountains. These massive avalanches baffled glaciologists because they would not normally occur on what were gentle mountain slopes. Scientists now think that the entire ice mass slipped off its bed when meltwater caused by rising temperatures made its way through the glaciers and created a layer of lubricating mud which caused it to slide down the slope.

This Tibetan case is just one of many illustrating how our understanding the climate induced changes in high altitude glaciers is evolving. To help understand these changes, the Intergovernmental Panel on Climate Change (IPCC) will include a chapter on High Mountains in its “Special Report on Oceans and Cryrosphere in a Changing Climate” to be released in September 2019. The cryosphere includes regions which are covered in snow or ice and so the report also includes a chapter on the Arctic and Antarctica.

GRID-Arendal’s Björn Alfthan recently spoke to Carolina Adler, Executive Director of the Mountain Research Initiative and one of the lead authors of the mountains chapter. He asked exactly what areas will be examined.

Carolina: The outline agreed by governments included a specific request for us [authors of the chapter] to address climate change in tropical mountain glacier regions. To be able to address this request, we only address areas in the tropics and mid-latitudes with permanent snow, ice/glaciers, and permafrost – features of high altitude mountains in these climate zones.

Björn: The original Swiss request for a special report on mountains emphasised the importance of understanding the impacts of climate change on hydropower production in mountain regions. Does the chapter discuss this in detail?

Carolina: What we are really looking at in the report are the implications of climate variability on cryosphere change. How does climatic variability impact snow, ice and glacier change patterns, and what direct impact this has on what we call the “cryospheric services” – the main one being water. The implications of climate change on water are assessed across several sectors, not just hydropower, but also irrigation and general drinking water supplies and other uses of water. We also touch on tourism and recreation given this is a key ecosystem service delivered by high mountain landscapes.

Björn: The oceans are all connected but high mountains are like small islands in a sea of lowlands. Does that limit your ability to draw broad conclusions that apply to all mountain regions?

Carolina: You’ve touched upon one of the main challenges we face. Mountain regions are so geographically distributed and each mountain region has its own context which makes it difficult for us to generalise across all regions. Our colleagues on the oceans chapter talk about a “systems-oriented approach” in their assessment but it’s much more difficult for us to do the same. Here, the mountain research community needs to focus more on methodologies that could allow us to say something comparable and consistent across several mountain regions.