Scientists have blamed climate change for yesterday’s flash floods in Nepal.
The devastating event saw rushing waters reportedly reaching up to 650ft high, sparked by the collapse of a glacier.
While scientists are still studying the exact causes of the disaster, Dr Wouter Buytaert, Reader in Hydrology and Water Resources at Imperial College London, says that climate change is to blame.
‘It is exactly the type of event that is triggered by climate change,’ he explained.
‘Global warming shrinks glaciers, making it more likely for them to break apart. Land degradation, due to increasing wildfires, extreme weather, and unsustainable land use, destabilizes valley slopes and mobilizes rocks and sediment.
‘In mountain regions with steep slopes and narrow valleys, this creates the perfect conditions for events such as this.’
The floods come just one month after an ominous study was published, warning that global warming could spark glacial collapse in the region.
The study, led by researchers at Kathmandu University, explained: ‘Across the Himalayan region, warming rates exceed the global average, intensifying climate–related hazards and associated losses contributing to the melting of glaciers and increasing the risk of GLOF [glacial lake outburst floods].’
Nepal is facing what officials are describing as ‘devastation beyond imagination’ after flash floods wiped out buildings and bridges along the Nepal–Tibet border
The United States Geological Survey (USGS) first reported the event as a magnitude 4.4 earthquake.
However, it has since confirmed that a GLOF was to blame.
‘Additional analysis of nearby seismic stations, long period seismic waves, and satellite imagery led to the determination that the seismic event was instead a glacial collapse and debris flow, and that no earthquake had occurred,’ the USGS told the BBC today.
Dr Adrian McCallum, a Glaciologist and Polar Engineer at the University of the Sunshine Coast, agreed that climate change is likely to blame for yesterday’s event.
He said: ‘I’m yet to fully appraise myself of the situation, but these floods are probably “glacial lake outburst floods” (GLOFs); these are increasingly common in alpine regions globally as our climate changes.
‘As glaciers melt and recede, ice turns to water, the water is stored (temporarily) behind natural moraine dams, but when those dams breach, tremendous amounts of water can be released down a valley, taking out everything in its path.’
Meanwhile, Dr Ella Gilbert, a climate scientist at the British Antarctic Survey, explained that global warming is destabilising glaciers in the region.
‘We can’t say definitively yet what the links to climate change are, but we know that climate heating is destabilising glaciers in the Himalaya, with the rate of loss doubling since 2000,’ she explained.
Flooding is often associated with rainfall. However, early reports suggest that a GLOF was to blame for yesterday’s event
‘When glacier stability is undermined, sudden failures can occur, leading to horrible incidents like this one.
‘Mountain glaciers worldwide are under threat from climate heating – particularly those in tropical regions.
‘The higher temperatures rise, the greater the risk of sudden and devastating collapse.’
Nepal is highly vulnerable to climate change for a number of reasons.
Writing in last month’s study, published in Frontiers in Climate, the researchers explained: ‘Nepal, a mountainous, landlocked and least developed country in the eastern Himalayas, is highly vulnerable to climate change due to its complex topography, fragile ecosystem and limited ability to adapt to rapidly growing climate impacts.
‘The vulnerability is exacerbated with increased frequency and intensity of climate induced disasters, such as floods, landslides, glacier retreat and glacier lake outburst floods (GLOF), among others, leading to loss and damage.’
While yesterday’s GLOF was particularly devastating, it’s by no means the only one in recent years.
According to last month’s study, at least 45 GLOF events have occurred across 39 lakes in Nepal – with several resulting in loss of life.
While yesterday’s GLOF was particularly devastating, it’s by no means the only one in recent years
According to last month’s study, at least 45 GLOF events have occurred across 39 lakes in Nepal – with several resulting in loss of life
Worryingly, scientists say that as temperatures continue to rise, GLOF events will become more frequent.
‘Nepal is already experiencing significant climate–induced loss and damage across multiple sectors at the current level of global warming,’ the researchers warned.
‘An event specific climate attribution study for September 2024 extreme rainfall in central Nepal shows that in a 1.3°C warmer world, the intensity of the rainfall was approximately 10% higher and the probability of occurrence about 70% greater.
‘With temperature exceeding 1.5°C, the risk of floods, glacier melt, GLOFs and droughts would significantly increase.’
With the true extent of the devastation only just beginning to emerge, scientists hope yesterday’s disaster will trigger the development of future warning systems.
Dr Nader Naderpajouh, an expert in risk and resilience at the University of Sydney, said: ‘This unique event may trigger the implementation of future warning systems, which is feasible with current state–of–the–art technology.
‘At least the buildup of water can be an early warning sign for downstream communities, a form of seasonal warning for preparation.
With the true extent of the devastation only just beginning to emerge, scientists hope yesterday’s disaster will trigger future warning systems
Scientists say that as temperatures continue to rise, these types of floods will become more frequent
‘Such communications and preparations can save lives and reduce the impact at scale.
‘With global warming, there is an expectation that similar patterns of disasters will recur.
‘We can benefit from the implementation of a warning system, similar to those triggered for tsunami warnings after 2004’s tsunami.’
