Why Is Nepal So Vulnerable to Flooding?

Catastrophic flooding in Nepal and Tibet is laying bare the risks mountain villages stand to face amid human-induced global warming. 

Maheshwar Dhakal, Nepal’s climate change chief in the Ministry of Agriculture, Forest and Environment explicitly blamed climate change for the flooding, while the country’s foreign minister, Shisir Khanal urged world leaders to undertake a "global effort" to tackle climate change. 

"We'd ask the world... to take climate change as one of the major challenges that Nepal and its citizens face, and this has to be a global effort," Khanal said. "We request the global community to come together and preserve the Himalayan ecosystem."

The death toll from catastrophic flooding at the Nepal-Tibet border has now surpassed 1,000, with more than 4,000 people still missing.

The country has seen a number of deadly climate events and natural disasters in recent years. Landslides and flooding devastated the region in 2012 and 2017, meanwhile in 2015, a 7.8 earthquake killed close to 9,000 people and triggered more than 20,000 landslides across 14 districts of Central and Western Nepal. 

While it’s too early to know exactly how climate change might have contributed to this August’s disaster, experts say that as our planet continues to warm extreme weather events are only going to become more frequent—especially in climate vulnerable nations like Nepal. The United Nations has warned that millions of people in the Himalayan region face severe risks from future glacial floods in the coming years.

Why is Nepal so vulnerable to extreme flooding?

Nepal has a complex topography—ranging from low-lying planes to some of the world’s highest peaks. Last week’s flooding was triggered by a landslide, which caused a glacier to fall, sweeping rocks and melted water into a number of villages downstream. 

“These landscapes up in the high Himalayas are very dynamic,” says Göran Ekström, professor of earth and environmental sciences at Columbia University. “There's a lot of erosion going on. There were landslides there before there was global warming, but global warming has been speeding up that erosional process, and so everything is happening faster, including the number of big landslides up there.”

Over the decades, economic activity has concentrated in riverbank towns and villages below—putting those growing communities at risk. 

“Economic development has increased along the rivers. Tourism has expanded. A growing number of hydropower facilities have been built,” says Rajiv Ghimire, lecturer at the University of Michigan’s school for environment and sustainability. 

That means that the area where the floods occurred has become far more populated than it once was. “They have always had these flooding events,” says Ekström. “It's just that now we have a lot more people and infrastructure in these steep valleys. What 100 years ago maybe would have killed dozens of people now kills hundreds of thousands of people.”

How can Nepal prepare for future climate disasters?

Nepal lacks early warning systems that might have made evacuations easier. Mathias Vuille, professor of atmospheric and environmental sciences at the University at Albany, SUNY, notes that, in Switzerland, a landslide and glacial collapse buried a small village last year—but only one person was killed thanks to warning systems. 

“We know about the threat, and we're not completely helpless,” says Vuille. “We can adapt, and while we can't prevent the process from occurring, we can limit the impacts again, mostly by setting up these warning systems, and having the right plans in place.” 

Ghimire stresses the necessity of thinking about the climate risks when it comes to building in the future. “Himalayan mountains are fragile, so we need to anticipate situations like this as we are building infrastructure,” he says.  

Adaption measures will only become more important in a warming world. Nepal produces less than 0.1% of global greenhouse gas emissions, yet is among one of the most climate vulnerable nations in the world. The Himalayan region is warming nearly twice as fast as the global average, leaving Nepal vulnerable to more crises in the face of retreating glaciers and thawing permafrost. 

“When we take away the glaciers, we are disturbing the steady state of equilibrium that has existed,” says Ekström. “So for places like Nepal and other places around the world…where the glaciers are disappearing, they are having more landslides because glaciers have been stabilizing the landscape. So we should expect more of these events.”