Sikkim crisis underscores urgent need for climate mitigation efforts, says expert

South Lhonak Lake, situated in a high-altitude glacierised region, experienced accelerated melting due to climate change

In the event of global warming, by 2100, glaciers are set to lose 30 percent –50 percent of their volume , Anjal Prakash, Clinical Associate Professor (Research) and Research Director at the Bharti Institute of Public Policy at the Indian School of Business, tells Moneycontrol. Excerpts.

What factors led to the Sikkim disaster?

The Sikkim disaster was primarily triggered by a catastrophic combination of factors. It began with a cloud burst over Lhonak Lake in North Sikkim, leading to excessive rainfall. This deluge, aggravated by the release of water from the Chungthang Dam, caused flash floods. The geography of Sikkim, nestled in the Eastern Himalayas, played a role, with its high-altitude glacierised areas hosting numerous glacial lakes, including the expanding South Lhonak Lake. Past studies had warned of its potential to burst, amplified by glacial retreat.

The disaster highlights the dangers of climate change, emphasising the urgent need for monitoring, mitigation measures, and disaster preparedness in the Himalayan region.

Both in case of Himachal and the Sikkim floods, cloudburst is considered to be a factor. Are they becoming more common with climate change?

Yes, cloud bursts are increasingly linked to climate change. As global temperatures rise, the atmosphere can hold more moisture, leading to more intense rainfall events. This heightened moisture, combined with changing weather patterns, contributes to an increased frequency of extreme precipitation, including cloud bursts. Both Himachal and Sikkim have experienced such events, highlighting the growing vulnerability of regions worldwide to these climate-induced phenomena.

It underscores the urgent need for climate mitigation efforts and adaptive measures to protect communities and infrastructure from the escalating risks associated with changing precipitation patterns.

What is a glacial lake outburst flood? How was it responsible for the Sikkim flood?
A glacial lake outburst flood (GLOF) is a sudden and catastrophic event where a glacial lake, often dammed by a glacier or moraine, bursts open, releasing an immense volume of water, rocks, and debris downstream. In the case of Sikkim's flood, South Lhonak Lake, situated in a high-altitude glacierised region, experienced accelerated melting due to climate change. This led to the lake's expansion and the formation of a significant amount of meltwater.

The pressure and volume reached a critical point, causing the lake to breach its boundaries. The resulting GLOF, combined with excessive rainfall, triggered the devastating flash floods in Sikkim.

Also read here: At least three hydropower projects of 2,210 MW affected in Sikkim

Glaciers in the Hindu Kush region of the Himalaya mountains are melting at the fastest rate ever. What is the pace at which they melt?

As per recent ICIMOD report (HI-WISE report) - in the event of global warming between 1.5°C to 2°C, by (the year) 2100, glaciers are set to lose 30 percent–50 percent of their volume compared with 2015. For 3°C, between 55 and 75 percent will be gone. For 4°C, between 70 and 80 percent will disappear.

Which parts of the world will the melting Himalayan glaciers impact? What are the consequences?

The melting Himalayan glaciers will impact a vast region, affecting countries like India, China, Nepal, Bhutan, and Pakistan, which rely on these glaciers for freshwater resources. As the glaciers shrink due to global warming, there will be reduced water availability for agriculture, drinking, and hydropower generation, leading to potential food and energy crises.

Furthermore, the accelerated glacial melt contributes to rising sea levels, posing a threat to coastal areas globally. The loss of glaciers also heightens the risk of natural disasters like floods and landslides.

Overall, the consequences of Himalayan glacier melting extend far beyond the immediate region, affecting millions of people and ecosystems.