Work is at last under way to create an early-warning system, in the mountains around Huaraz in Ancash, that might mitigate the dangers of avalanches caused by glacial melt.

An avalanche fall into a high altitude lake in the Andes can cause a tsunami of water, ice and debris overtopping and/or destroying the natural barrier which forms the lake. The tsunami torrent can then race down thousands of feet into the populated valleys below. In the past there have been horrific numbers of deaths from such occurrences: 1,500 in Huaraz in 1941 and 20,000 that buried Yungay in 1970. The avalanche when it reached and then engulfed Yungay is estimated to have contained 80,000,000 cubic metres (eg 2km by 2km by 20m) of water, mud, rocks and snow. The danger is increasing as the global temperature rises (in Peru 2oC since mid-1800s) and with ever more people concentrated in valley towns.

In spite of bureaucracy, efforts have been made to introduce systems to monitor lakes, give warning to the populace and reduce the volumes of water contained. But in some cases locals have destroyed these systems and delayed engineering works. There is a lack of trust, based on numerous fears: that glaciers become jealous of too many people around them and themselves cause slides; that the monitoring stations control the weather; that the work is a precursor to mining activities etc.

In trying to make the situation safer, government and researchers must make more efforts to inform people what is happening, explain why climate is changing, and how it will affect them. Obtaining ‘social licence’ for such activities, and indeed others in industries like mining and oil & gas, is vital in overcoming such fears.