Will climate change spell the end of coal and hydropower in the Mekong?

Water dwelling on the lake of Tonle Sap, near Siem Reap, Cambodia. Photo: Jialiang Gao

As droughts and flooding in the Mekong River basin become harsher and more frequent due to the effects of climate change, coal and hydropower may no longer be viable development paths for the region.

By Skylar Lindsay

This year has been rough for the 70 million people who call the Mekong River basin home:  a severe drought rocked the region for months before yielding to deadly flooding

The Mekong slowed to its lowest level in recorded history, knocking the world’s largest freshwater fishery—Cambodia’s Tonle Sap Lake—out of balance. The drought hurt the region’s fishing and farming communities, threatening its food supply. When the rain came, flooding reportedly displaced at least 100,000 people in Laos alone.

Mainland Southeast Asia is among the most vulnerable regions in the world to the impacts of climate change: according to one Global Climate Risk Index, Myanmar and Vietnam are in the top 10 most vulnerable countries. Cambodia and Thailand are in the top 20.

Despite its vulnerabilities, the governments of the lower Mekong are still pushing development plans centred on unsustainable hydropower dams and coal. Dams across the Mekong basin and coal power plants will ostensibly provide much-needed electricity and income, but the impacts of climate change on water resources are throwing all of this into question. 

Locals panning for gold near Xayaburi dam in Northern Laos.
Photo: Prince Roy

Not only do large dams and coal power plants exacerbate the impacts of climate change, but new research suggests that declining freshwater resources will dramatically cut the amount of power these projects can produce, reducing their value for investors, developers and host countries. 

Climate change tops the list of risks for the Mekong

According to research by the World Economic Forum, businesses consider environmental risks to be their biggest concern for doing business in East Asia and the Pacific.

Annual flooding is vital to the Mekong basin, transporting nutrients across the ecosystem, from the upstream rice farms to delta itself. The intergovernmental Mekong River Commission (MRC) has estimated that annual flooding in the river basin brings US$8-10 billion into local economies across the region.

But a study by the UN Economic and Social Commission for Asia and the Pacific (UNESCAP) in April warned that drought in Southeast Asia will worsen and affect a larger portion of the region. In one possible scenario analyzed in the study, 96% of ASEAN could be affected by drought between now and the year 2100. This climate change-induced drought is expected to hit lower-income groups the hardest and contribute to rising inequality.

Cambodia’s Tonle Sap Lake supports a US$2 billion fishing industry and supplies local people with 500,000 tons of fish—more than three times the total freshwater fish catch from all of North America’s rivers and lakes combined. Every year, the Mekong swells with the rains of the monsoon and eventually pushes up into a tributary of the lake, the Tonle Sap River, changing the direction of its flow. As floodwaters pour into the lake, the area covered by the Tonle Sap increases sixfold, washing nutrients and fish into communities around the lake. Because of this year’s drought, the Tonle Sap River reversed direction two months later than usual.

Climate change is also bringing dangerously unpredictable flooding, especially as dam operators let floodwaters through in an effort to avoid disasters like the 2018 collapse of the Xe Pian Xe Nam Noy dam in Laos.

“Flood damages will rise rapidly by a factor of 5-10 with development unless protection is provided,” the MRC wrote in a 2018 study. When the Nam Theun 2 dam in Laos began releasing water in early September, it led to flooding in 12 villages.

In the Mekong Delta, Vietnam’s agricultural backbone faces dual threats of unpredictably heavy rains and rising seas due to climate change. A study published last month by Philip Minderhoud, a geographer at Utrecht University in the Netherlands, shows that the delta is, on average, only 0.8 meters above sea level, nearly two meters lower than previously thought, meaning it’s that much more vulnerable to flooding from extreme weather and encroaching seas.

Vietnamese rice fields.
Photo: Walkers.sk

This “new normal” of oscillating between intense drought and severe flooding has shifted the ground on which Mekong governments have built their plans for hydro and coal-fueled development.

“Damn the weather”: governments continue to back large hydropower regardless 

Thailand, China and more recently Vietnam are looking to Laos for cheap, reliable hydropower, supporting its plans to become the “battery of Southeast Asia.” But in an era where drought wracks the basin every few years and water resources are stretched to their breaking point, that power supply is no longer stable.

In late September, Laos announced plans to move ahead with the Luang Prabang dam, the eleventh hydropower project on the mainstream of the lower Mekong. 

The dam is being constructed by the Lao government and PetroVietnam, a Vietnamese state-owned enterprise. The members of the Mekong River Commission—Laos, Cambodia, Thailand and Vietnam—will meet in October to review the project.

 “In July this year, the Xayaburi dam was test-running electricity in the area near the Thai-Lao border, [accelerating] the unusual drought [conditions]. If Luang Prabang dam is built, I think the crisis will get worse,” an energy expert from Thailand’s Sarakham University told Radio Free Asia. This is to say nothing of the 11 dams that China has built on the mainstream of the Mekong.

With the Mekong’s water resources strained, the river may no longer be able to support coal power

Coal is the single largest driver of global climate change and Southeast Asia is the only region of the world where the percentage of energy supplied by coal grew in 2018. A study published in Energy and Environment Science in September showed that changing weather patterns means coal power is also no longer a reliable bet for even short-term development.

The study considered plans for over 490 gigawatts of new coal-fired power plants in Asia tipped for completion by 2030, a 30% increase from current capacity. Models suggest that the water resources these power plants rely on for cooling will be dramatically reduced in the coming years, significantly decreasing the amount of power these plants can provide.

“One of the impacts of climate change is that the weather is changing, which leads to more extreme events—more torrential downpours and more droughts,” said Jeffrey Bielicki, co-author of the study and associate professor at The Ohio State University. “When you don’t have the rain, you don’t have the stream flow, you can’t cool the power plant.”

This casts serious doubt on Cambodia’s recently-announced decision to purchase 2,400 megawatts (MW) of power from new coal-fired power plants in Laos. The future looks similarly bleak for coal megaprojects like the 1878-MW Hong Sa plant in Laos and the ever-expanding Tigyit plant in Myanmar’s Shan State.

Southeast Asia’s coal and hydropower roadmap no longer leads to development

Communities who speak out against large hydropower dams and coal power plants aren’t necessarily anti-development. The governments of the Mekong have a right to push for access to electricity and better lives for their citizens. But the risks of climate change mean that coal and large dams are no longer viable paths towards development.

The Global Climate Risk Index measures countries’ vulnerabilities in terms of the relative number of fatalities and losses to GDP due to climate change. The high climate vulnerability ratings given to Cambodia, Myanmar, Thailand and Vietnam mean that their plans for development need to be grounded in climate resilience and adaptation, not fossil fuels and dams along an already embattled river. 

As these projects threaten the food supplies and livelihoods of communities along the Mekong, the financial resources and political energy behind them would be better directed towards renewable energy solutions.

“More dry years are inevitable, but more suffering is not,” said Armida Alisjahbana of UNESCAP. “Timely interventions now can reduce the impacts of drought, protect the poorest communities and foster more harmonious societies.”