The valley is the main link between Kathmandu in Nepal and Lhasa in Tibet. There was little warning. More than 150 people are dead and hundreds more missing after an enormous wave of water, ice, mud and rock cascaded more than 170 kilometres down the Bhote Koshi River valley in Nepal. At least 34 Australians are missing.
In good news, the Green Climate Fund last year announced funding for better monitoring systems in Nepal. As climate change intensifies, glaciers worldwide are melting – even in high regions such as the Himalayas . As temperatures rise, these slopes are beginning to melt or destabilise. If an earthquake or slope failure occurs, it can trigger a sudden and devastating debris flow. The high-elevation glaciers of the Himalayas can respond differently to climate change than glaciers at lower elevations or in relatively warmer regions. Thawing and degrading permafrost can also contribute by making steep Himalayan slopes less stable. As the climate warms, the ground can thaw, weakening the ice that helps bind rock and soil together. As temperatures rise and climate-related disasters become more frequent or severe in some regions, early warning systems will become increasingly important for villages and towns located near glaciers or thawing permafrost. These systems can monitor rapidly rising river levels, intense rainfall and seismic waves to alert authorities before disaster strikes. However, installing and maintaining effective early warning systems can require significant investment. That’s a challenge for lower-income and developing countries. As the climate warms, increased glacier melt can temporarily increase river flows and, in some places, contribute to flood risk. But as glaciers continue to shrink, their contribution may eventually decline and lead to less water availability – particularly during the dry season. Rapidly reducing greenhouse gas emissions, investment in early warning systems and better monitoring of vulnerable mountain regions can help communities prepare. These measures cannot prevent every disaster, but they can save lives and give people a better chance to adapt to a changing climate.
Because the steep slopes of many of these very tall mountains are made of permafrost – rock and soil frozen for centuries, the Himalayas are especially vulnerable,. Permafrost is ground containing rock, soil and ice that has remained at or below 0°C for many years.
