Tsunami in the sky

Bhutan, the landlocked country of South Asia, achieved the status of being the world’s first carbon-negative country. This began in 2009 when the government initiated special measures to achieve this status. This included putting a ban on log exports, having the country’s total land to be covered by 60% of forests (as stated in the country’s constitution), and generating free hydroelectric power through rivers.

While this has helped Bhutan to pursue its plan to achieve zero net greenhouse emissions by 2030, and it is not contributing to global warming, it is facing an unprecedented natural calamity as we speak - climate change.

The rise in global temperatures has resulted in the melting of glaciers. Bhutan is no exception, especially when it comes to the water levels rising because of the formation of these glacial lakes. This is making many of Bhutan’s villages face the threatening disaster called the glacial lake outburst flood (GLOF). This is caused when the natural dam of a glacial lake breaks owing to the accumulation of large amounts of water.

Imagine living in Bhutan’s remote village of Luana which is situated in the Gasa District, nearly 4,200 meters above sea level. This cluster of 17 villages does not see any external visitors at all and has remained hidden between mountains. It takes a 7-day trek to reach Luana from Thimphu, Bhutan’s capital.

Surrounded by snow-capped mountains, Luana has four glacial lakes, Lugge, Thorthormi, Rahpstreng, and Beytsho that pose an imminent threat to its residents. The rising water levels as a result of the formation of glacial lakes pose a risk of outburst flood in this area.

Karma, a glaciologist, has warned that Bhutan may face a ‘tsunami in the sky’ if there is a combined explosion of water from the Thorthormi and Rahpstreng glacial lakes. This may trigger an outburst flood that will be way greater than the one in 1994. This GLOF resulted in the loss of life and property, farmland, and infrastructure. It also destroyed the area’s biodiversity.

Residents of Thanza, the village most prone to a glacial lake outburst flood say that they have nearly 20 minutes to evacuate their homes and reach higher grounds in case such a flood moves their way.

Karma mentions the possible damage that the Thorthormi and Rahpstreng glacial lakes will create. “Rahpstreng is a fully developed lake, while Thorthormi is in a growing phase. Our fear is that one day Thorthormi will turn into a fully developed lake like Rahpstreng. Should this happen, the moraine dam will not be able to hold the hydrostatic pressure from Thorthormi and lead to the convergence of the two lakes. The water from Thorthormi will flow into Rahpstreng and trigger a combined flood with an estimated flood volume of 53 million cubic metres gushing down the Pho Chhu basin.” (Source: UNDP Bhutan)

Such a catastrophe will damage two of Bhutan’s biggest hydropower projects: the 1200 MW Punatsangchu-I and 1020 MW Punatsangchu II. Both are located downstream of these lakes.

Climate change has also disrupted life in Bhutan. According to Kaka from the village of Tenchoe, the erratic weather patterns have increased residents’ worries. He added that several years ago Bhutan received its first snowfall in October. However, now the months of March and April receive snow. By the mid of the year, the weather becomes warm and the snow begins to melt.

According to a resident, Dorji Wangmo, from Thanza, the village closest to the lakes, “It scares me when I hear of how climate change is disrupting everything. Why wouldn’t I be scared? We live just next to the lakes. Today, we fear climate change might trigger GLOF. And soon there will come a day when we have no water if the glaciers continue to melt at the current rate. Snowfall has become rare already.” (Source: UNDP Bhutan).

Unfortunately, the glaciers are retreating faster than expected in the Himalayan region. The government of Bhutan needs to take immediate action to avert this crisis or to provide safety to the residents – living in threatening areas close to the glaciers. Bhutan needs collective effort and collaboration from the regional and international allies in this regard. Despite the presence of the GLOF threat, most of Bhutan’s mountainous terrain and valleys are in the path of flash floods and landslides. GLOF, therefore, becomes a major worry because of climate change. According to the World Glacier Monitoring Service, Bhutan has nearly 2,674 glacial lakes out of which 25 are potentially dangerous.

To avert the crisis, Bhutan has placed a cap on the number of tourists that can visit the country in a year. They are also requested not to harm the environment. Furthermore, Bhutan has been collaborating with international organizations to develop an early warning system and an emergency response plan. The United Nations Development Programme (UNDP) is working with Bhutan to develop and implement a national disaster risk reduction platform to deal with respond to disasters such as the GLOF. Bhutan requires immense financial services to mitigate risks posed by climate change. The country also lacks the resources to gather, measure, and analyse scientific data to monitor glacial lakes. There is no historic data valuable based on which predictions can be made on the intensity of the GLOF.