Projections show striking changes ahead
The latest findings from the Climate Model Intercomparison Project Phase 6 (CMIP6), 2024 highlight alarming changes in Bhutan’s climate, providing crucial insights that underscore the urgency of addressing climate change impacts in the region. This comprehensive report, the result of concerted scientific research and international cooperation, sheds light on Bhutan’s unique vulnerabilities stemming from its geographic, topographic, and socio-economic characteristics.
According to the CMIP6 projections from the National Centre for Hydrology and Meteorology (NCHM), Bhutan is expected to experience significant increases in both seasonal and annual precipitation levels, with these changes becoming more pronounced under higher emission scenarios. “By 2060, the precipitation is likely to increase across the country although the increase is more in the north, west, central and south-western districts and less in east and southeastern districts,” the report stated. The northern, western, northwestern, and southwestern regions of the country are predicted to face heightened risks of flooding and related disasters. Conversely, areas in the east and southeast may encounter decreased precipitation, suggesting potential drought conditions and water scarcity up to the year 2060.
Temperature analyses reveal a worrying trend as both maximum and minimum temperatures are anticipated to rise throughout the country by the year 2100, particularly under more extreme emission scenarios. Notably, minimum temperatures are projected to rise more sharply than maximum temperatures, with the northern and central regions facing acute risks of heatwaves and accelerated glacial melt.
IPCC AR6 has highlighted that elevation dependent warming is likely to continue in the mountain regions in Asia under the climate change conditions. Additionally, the rate of warming might be amplified with elevation, for example, the high mountain environments may experience faster changes in temperature than that at lower elevations.
The report states, “More than 100mm increase is likely in Haa, Samtse, Paro, Punakha, Thimphu, Chhukha, Gasa and Wangdue Phodrang. Under SSP2, the highest increase is likely in Punakha (171 mm) followed by Gasa, Thimphu, Paro, Bumthang and Wangdue Phodrang which are likely to receive around 150mm more precipitation than the baseline. Under the worst-case scenario, all the districts are likely to receive at least 300mm more precipitation from the baseline with the highest increase in Punakha.”
The monsoon season in Bhutan spans from June to September, accounting for over 70% of the country’s annual rainfall. During this period, the southern districts experience the highest levels of precipitation. However, projections for the near term (2040) indicate that the eastern and southeastern districts, specifically Trashigang, Samdrup Jongkhar, Pema Gatshel, and Monggar may see a slight reduction in monsoon rainfall—up to 30 mm under the worst-case scenario. Additionally, the area at risk of experiencing decreased precipitation relative to baseline levels is expected to widen under the SSP2 4.5 scenario.
The implications of these temperature changes are profound, particularly concerning Bhutan’s glacial mass balance. Projections indicate a decrease in glacial mass until 2100, primarily driven by global warming. The Manas river basin is forecasted to bear the brunt of these changes, with increasing glacial melt leading to short-term boosts in river runoff but posing long-term risks of reduced water availability and seasonal drought, particularly where rainfall patterns are also expected to decline. The Wang Chhu basin is predicted to be significantly affected by reductions in glacial runoff.
Climate change impacts in Bhutan are disparate and are likely to exacerbate existing vulnerabilities across various sectors. Agriculture, hydropower, water supply, and construction—key components of Bhutan’s economy—face serious threats. High-population areas are bracing for increased precipitation and temperature effects: rice-producing regions in the east may struggle with water scarcity, while areas in the west, south, and north could experience flooding.
“Climate-induced disasters may outpace the country’s ability to adapt,” warned a climate expert involved in the study. “To mitigate risks, it is crucial to implement risk-informed adaptation strategies that focus on the most vulnerable sectors and communities. Identifying priority areas for investment can help build resilience at local and national levels.”
As Bhutan prepares for these impending climate changes, the report underscores the necessity of evidence-based policy decisions to enhance social and economic outcomes. Continued commitment to scientific research and collaboration is vital for strengthening the nation’s capacity to cope with the changing climate.
In the meantime, as Bhutan stands at a pivotal moment in its climate trajectory, the insights gleaned from the CMIP6 projections serve as a clarion call for immediate and concerted action. “It is imperative for policymakers, communities, and stakeholders to come together to navigate the challenges ahead and fortify resilience across the kingdom to secure a sustainable future for all,” the Climate Change Projection Report, May, 2024, underlines.
By Sangay Rabten, Thimphu
