Mountainous regions face catastrophic impacts without urgent climate action

Human activities are damaging the planet at an alarming and unprecedented rate. The latest report by the UN climate science body IPCC, released this week, lays out startling facts on global warming. The report acts as a stark reminder that inaction will exacerbate the climate-related impacts the world is already facing. It confirms that Earth’s temperature is higher now than it has ever been in the last 125,000 years.

The world has already warmed on average by 1.1°C compared to pre-industrial times due to human induced climate change. Each of the last four decades has been successively warmer. As a consequence, climate extremes such as heat waves, extreme precipitation, droughts and storms are on the rise, including in Nepal where floods have already claimed about 100 lives just this year.

Unprecedented pace of glacier retreat

There is no doubt that mountainous regions are at the forefront of climate impacts:  for example, high intensity rain and mountain slope instability can wash out roads and bridges, thereby affecting access to rural areas, and rapid change in mountain snow will have far reaching effects on both upstream and downstream.

The IPCC report confirms that the rate of ice sheet loss increased by a factor of four in the last three decades. Through their climate warming greenhouse gas emissions, humans are the main cause of the global retreat of glaciers. The current rate of ice sheet loss, with almost all of the world’s glaciers retreating synchronously since the 1950s, has been unprecedented in at least the last 2,000 years.

The unprecedented pace of glacier retreat at the global scale is more alarming in the Himalayas. Two years ago, the Hindu Kush Himalaya Assessment report by ICIMOD confirmed that even if global warming is limited to 1.5°C, temperatures will remain at least 0.3°C higher in the Hindu Kush Himalayas (HKH), and at least 0.7°C higher in the northwest Himalaya and Karakoram regions of Pakistan. As a consequence, 36% of the glaciers in the region will be gone by 2100. And this is the “best case” scenario where the world manages to limit warming to 1.5°C and avoid the worst impacts of climate change.

Climate change is also intensifying the water cycle and affecting rainfall patterns. The IPCC report confirms that the intensity and frequency of hot extremes, including heat waves, and heavy precipitation, as well as agricultural and ecological droughts continue to increase as temperatures rise. For South Asia including Nepal, the average precipitation as well as heavy rainfall events are projected to increase. This will result in more flooding and landslide events. All this will have far reaching consequences across the region with water-dependent energy sectors and water-intensive agricultural systems.

Highlands to Islands linkages

The impacts of melting glaciers are not only limited to the mountainous regions. Rapid ice sheet melt could lead to catastrophic sea level rise even before the end of the century. As outlined in the IPCC report, the global mean sea level has already risen by 20 cm and will continue to do so for thousands of years.

The IPCC report confirmed that combined ice sheet and glacier mass loss contributed to 42% of this global mean sea level rise from 2006 to 2018.

The report states with greater certainty than previous reports that mountain and polar glaciers will continue melting for decades and centuries to come. Continued ice sheet loss will also release greenhouse gases into the atmosphere -- as temperature rises and permafrost thaws, it decomposes and emits carbon, further amplifying climate change that is causing it to melt.

Rising temperatures could melt most mountain glaciers and add more to the sea level rise, both leading to the extinction of small islands and mountain habitats. This cycle that binds the highlands to the islands demonstrates the need for collaboration between mountainous and island countries in the international climate change discourse.  Such collaboration could help to amplify the voice of most vulnerable nations calling for the major emitters to take urgent actions to reduce emissions.

Path to follow

The IPCC report clearly shows the grave risks of exceeding 1.5°C above pre-industrial levels – an upper limit of warming which the global community has agreed to in the Paris Agreement. Yet, from the perspective of a mountainous country, even a 1.5°C temperature rise is too much, which will lead to one third of the Himalayan glaciers to disappear with devastating consequences for the region.

All decisions from now on, therefore, must be guided by the fact that every extra tonne of carbon dioxide and other greenhouse gases will lead to more warming and any increase in warming will lead to devastating impacts on lives, livelihoods and ecosystems across the world.

The most vulnerable countries, including mountainous areas, are already at the forefront of fatal climate and weather disruptions. These countries with limited resources will continuously require international support to combat climate change, and at a scale well beyond current levels. The IPCC report must act as a wakeup call for all governments, in particular the biggest polluters such as the G7 and G20. They must take urgent action in response to the climate emergency, starting by adopting robust and bold 2030 climate commitments by the next UN climate summit - the COP26 - in November.

Manjeet Dhakal is Head of LDC Support Team at Climate Analytics and serves as an Advisor to the Chair of the Least Developed Countries Group at the multilateral process of the UNFCCC. He provides scientific, strategic and high-level climate leadership support for the LDCs’ in climate change UN-related processes.