The horrific
disaster in Nepal with the massive loss of life is a tragedy. It shows that we
have to get better at giving early warnings for such events.
It is true that global
warming makes glacial collapses more likely, but climate change is likely not a
determining factor in the floods and debris flows in the region. It is
certainly a factor since permafrost helps hold the ice, rocks, and mud
together, and heat impedes that ability. However, there are more proximate causes, such as frequent
earthquakes that make the region very unstable, including glaciers. According to Wikipedia:
“Such was the scale and speed of the flood, the leading
hypothesis of geomorphologists is that the collapsed portion of an unnamed
glacier fell thousands of metres and melted from the velocity and friction of
the impact. The meltwater and rocks then displaced the river in the valley.”
Glacier collapse, also known
as an ice avalanche, was likely the main cause.
“According to Daniel Shugar, a geologist at the
University of Calgary in Canada who reviewed satellite imagery after the event,
a 0.2 km2 (49-acre) piece of ice and rock broke off at about 5.2 km (3.2 mi)
above sea level and fell vertically about 1.2 km (0.75 mi) to the valley below.”
It has also been reported
that two barrier lakes formed after the collapse and that there is substantial
risk for those to fail, which would result in additional flooding that would
also be potentially catastrophic.
“Hydrologists noted that detecting and providing advance
warning for such high-altitude glacier-related failures is difficult.”
The region is tectonically active, prone to earthquakes, and features high relief or metamorphic rocks. However, no earthquakes were detected. The debris flow did, however, produce two large seismic events. The 2015 magnitude 7.8 earthquake had already destabilized the Langtang Lirung glacier, making it more prone to collapse.
Below are screenshots from before and after the glacier collapsed.
Effective Early Warning Systems are the Key to Reducing the
Loss of Life
Not unlike early warning
systems for tsunamis, early warning systems for catastrophic flooding due to
glacial collapses and breaching of glacial lakes can help reduce loss of life.
However, in regions like Nepal, those systems need to warn very quickly. The
current early warning systems in place are more focused on the seasonal monsoon
rains rather than on glacial collapses and lake breaches.
Experts and officials from
China and Nepal met three months ago in Kathmandu to discuss the potential for
disasters. According to Reuters, they:
“…discussed strengthening cooperation to monitor and
respond to floods, weather and glacier-related hazards, according to an agenda
prepared by the Nepali side and seen by Reuters.”
“The participants called for joint risk-reduction measures,
including inventories of glacial lakes and hazard mapping.”
“But two Nepali officials told Reuters they did not
receive as much information as they wanted from China on glacier risks and
water levels after the meeting and they feared insufficient data sharing could
hamper their ability to anticipate and prepare for major disasters.”
"What we actually wanted from them, and still want,
is if there are early movements of glaciers and early movements around that
area, we would want to know a bit early," said Sauhardra Joshi, a
hydrologist at Nepal's Flood Forecasting Division, who was in the May meeting.
Clearly, the two countries,
which have unstable and easily destabilized glaciers and breachable glacial
lakes on their shared border, need to have better scientific cooperation in
detecting changes. Modern satellite monitoring methods such as InSAR should be
employed and probably are. Both sides of the border are in danger of
catastrophic flooding, so cooperation in this area is vital. In particular,
Nepal has been wanting more and better cooperation with China, which has been
slower to implement such cooperation. A glacial lake breach in Tibet caused a
flash flood in the same area a few years ago that killed nine people.
"When the Chinese side sees a heavy precipitation
forecast in the Tibet area, then they provide us that forecast and those
observations," Parajuli said. But "not for avalanche and water level,
landslides, extreme events."
“China began sharing forecasts of heavy rain in Tibet
over China's WeChat messaging app and email a month ago, Parajuli said.
Reuters notes that China has
been sharing more data recently. They warned Nepal about the monsoon rains
earlier in the month and noted that flooding could occur and could trigger
events like landslides and flash floods. China is currently sharing information,
including monitoring data on a lake formed by debris from the flood. Effective
monitoring is made difficult by the rough and remote terrain and the fact that
geopolitical rivals India and China control part of the border region. The
glacier that collapsed, however, was in an unmonitored area. That certainly
suggests that monitoring networks should be expanded and filled in where
needed.
"That's not to forgive the fact that there isn't
really a well-articulated system. And there is very limited exchange between
Nepal and China," said Lord, who is part of a team supporting Nepal's
government on disaster and climate risk management.
"Chinese scientists have a much greater capacity,
have much greater resources for monitoring than those on the Nepal side overall."
The time between when the
collapse occurred and when Nepal was notified was 26 minutes. It would be
another 15 minutes, so 41 minutes in total when Nepal sent out cell phone
alerts. Nepal looked for data from closer stations but noted it was offline,
which suggested they were washed away. At least four monitoring stations were
destroyed in the flood. Clearly, a better and faster system is needed.
“Nepal's authorities will seek to work with China to
conduct research and build systems to monitor avalanches and the release of
water from glacial lakes — major risks for mountain communities — Parajuli said.
“He said his department will propose a data-sharing
agreement with China, along the lines of an arrangement that Nepal has with
neighbouring India, for more frequent information on precipitation and river
levels, not just high-precipitation forecasts.
“Nepal will seek data every 10 minutes so that "we
can warn our people, save our people," he said. "Our main target is
we shouldn't miss any future disaster."
This flood was a serious
torrent. It moved much faster than previous floods, which made the seconds and
minutes count more for early warning. Those seconds and minutes could have
saved many lives. Past floods have taken about 14 hours to reach the flooded
region, but this one, traveling near 100 miles an hour, only took about 40
minutes.
How Is Climate Change Related?
Perhaps the best answer is
that we really don’t know how much of a factor it was in this particular event.
Certainly, global warming accelerates glacial melt. Without any detailed
analysis, that is likely all one can say for certain. Another thing is certain
as well. Making changes in our fossil fuel use will not do anything significant
to help. It could, in time, make something more or less likely to happen, but
quantifying such risks is difficult. There are complicating factors in this
region. It is very active seismically, and those seismic events influence
glacier collapse. Heavy rainfall can influence such events as well. Thus,
climate, precipitation, and seismic events are all factors.
Roger Pielke Jr. wrote a
piece about the event in his Honest Broker blog. He noted:
“As now happens in the aftermath of every disaster, the
metaphorical ambulance chasers of climate advocacy seem to dominate the
discussion of why it happened and what to do in response — NPR, the New York
Times, the Associated Press and many others have each spent days trying to
convince us that climate change caused the disaster (or made it more likely),
and that emissions reductions are the solution.”
“The stampede of climate reductionism once again has us
missing what matters most for saving lives in the future.”
He cites human exposure and
vulnerability as necessary elements of the disaster that we can alter to
prevent such disasters in the future. He notes that population has nearly
tripled in the two downstream districts affected over the past 40 years and
that of the whole affected region has increased by a million people since then.
Pielke Jr: The U.S. Role in Monitoring
Pielke Jr. writes about the
U.S. ending its regional monitoring program involving USAID and NASA.
“Until January 2025 the United States supported this
type of vulnerability reduction in Nepal and across the broader region.
Specifically, SERVIR-Hindu Kush Himalaya (HKH) was a joint USAID and NASA
program with ICIMOD in Kathmandu, serving as a regional hub, covering
Afghanistan, Bangladesh, Myanmar, Nepal and Pakistan.”
“The program applied satellite Earth observation and
geospatial analysis to disaster risk reduction, water resources, land cover and
air quality. Its concrete outputs include Nepal’s National Land Cover
Monitoring System, annual forest-fire monitoring, flood and drought risk
services, collaboration with the Nepal Red Cross Society on risk communication,
and a collection of more than 170 public datasets covering glaciers, land
cover, disasters and vulnerability. The program described the region as acutely
exposed to water-induced disasters given its fragile geology, rugged terrain
and monsoon regime, and characterized inefficient risk communication as
increasing risks of disasters.”
He notes that the U.S. pulled
about $321 million from such funding during the purge.
“Jeremy Konyndyk, who ran the USAID response to the 2015
Nepal earthquake, wrote this week on X that DOGE keyword searches across
programs included “climate” and that identified the USAID–NASA collaboration on
flood prediction, early warning, disaster readiness, glacier inventories and
the mapping of dangerous glacial lakes in Nepal, along with seven other Nepali
disaster-risk-reduction projects.”
“These “climate” programs were then targeted for
termination.”
Konyndyk asks:
“Could these programs have helped foresee or mitigate
this week's glacial flooding catastrophe? Hard to say with an outlier event
like this. But that was their purpose.”
There are over 200 glacial
lakes considered at high risk for collapse and numerous glaciers as well.
Below is more information about monitoring and its difficulties and the necessity of cooperation.
“Early warning systems using remote sensors, cameras and
satellite monitoring have been piloted in Nepal, Bhutan, Pakistan and parts of
China. However, coverage remains sparse, and expeditions to install or maintain
sensors above 5,000 metre are logistically difficult, costly, and limited to
short summer windows. Nepal’s hazard sits in a transboundary basin. The
glaciers and upstream monitoring infrastructure lie partly in Chinese
territory. So effective warning depends on data-sharing and coordination across
the border.“
Future monitoring will be
impacted as well since monitoring stations were wiped out. Many bridges were
wiped out as well. Monitoring equipment was installed on bridges considered to
be safe from flooding.
“The incident shows that Nepal’s flood early warning
system needs to evolve beyond simply measuring water levels,” Khanal said. “It
must be capable of surviving extreme floods, transmitting data rapidly, using
backup sensors and issuing immediate warnings based on risk levels.”
He also stressed the need for continuous satellite
monitoring of glacial lakes considered at risk of bursting.”
He stresses that it is funding that is needed as well as expertise, and the U.S. has reduced it, putting more people in peril.
He concludes with a powerful and practical call
for the U.S. to provide more of both:
“That’s where the U.S. funding cuts matter — whether or
not the funding came through any one agency or another, the United States is
one of the few nations around the world with the resources to help less wealthy
countries implement such systems in support of vulnerability reduction. Such
efforts would not just save lives, but strengthen alliances in support of U.S.
interests.”
“Some might say it is not the responsibility of the
United States to support disaster risk reduction in places on the other side of
the planet.”
“To them I’d simply respond: First, if the U.S. can
contribute to the saving of thousands of lives anywhere — by investing dollars,
expertise, technologies, or other resources, ideally in collaboration with
other nations — that is money well spent. It is also the right thing to do.”
“And second, more parochially, some 90 Americans are
missing in the Nepal floods. It turns out that the world is a pretty small
place and we are all connected.”
Certainly, we should do all
that we can to prevent such loss of human life.
References:
Before
flood catastrophe, Nepal asked China for early warnings as risks mounted. Saurabh
Sharma, Devjyot Ghoshal and Sarita Chaganti Singh. Reuters. August 31, 2026. Before
flood catastrophe, Nepal asked China for early warnings as risks mounted
2026
Nepal Floods. Wikipedia. 2026 Nepal floods -
Wikipedia
What
Actually Caused the Nepal Disaster: Everyone wants to talk about climate
change, the actionable causes lie elsewhere. Roger Pielke Jr. The Honest
Broker. August 29, 2026. What
Actually Caused the Nepal Disaster
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