Climate Change

Tsunami in the sky

Despite becoming the world’s first carbon-negative country, Bhutan is exposed to the glacial lake outburst flood.

By Muhammad Omar Iftikhar | July 2023

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)

Read More