INDIA
Himachal Pradesh floods: More rain, less snow are turning Himalayas dangerousNavin Singh Khadka -
Environment correspondent,
BBC World Service
Thu, August 17, 2023
Increased rain and melting of snow and ice has made the mountain regions more dangerous, a new study finds
Torrential rains and unabated construction are frequently triggering disasters in India's Himalayan region.
But an unusual increase in rainfall is making the terrain even more dangerous.
Landslides and flash floods have already killed dozens in the area this month, burying homes and buildings. Parts of Nepal and Pakistan have also suffered damage.
A new study has found that mountains across the globe, including the Himalayas, are now seeing more rainfall at elevations where it has mostly snowed in the past.
The change has made the mountains more dangerous, scientists say, as increased temperatures not only bring rain but also accelerate melting of snow and ice. The rainwater also loosens the soil resulting in landslides, rockfalls, floods and debris-flows.
"Our findings provide several lines of evidence demonstrating a warming-induced amplification of rainfall extremes at high altitudes, specifically in snow-dominated regions of the Northern Hemisphere," says the study, published in June in the Nature journal.
The finding is consistent with a special report of the Intergovernmental Panel on Climate Change (IPCC) in 2019 which said that snowfall had decreased, at least in part because of higher temperatures, especially at lower elevations of mountain regions.
The Himalayan hazards nobody is monitoring
There are more instances of extreme precipitation events occurring now in the form of rainfall even at a high elevation and in all seasons, says Samuel Morin, executive director of the National Centre for Meteorological Research in France and one of the authors of the special IPCC report.
This is mainly because the zero-degree isotherm, the freezing level at which precipitation falls as snow, has moved to a higher elevation because of global warming
"As a result, these [mountain] regions are regarded as hotspots that are vulnerable to high risk of extreme rainfall events and related hazards of flooding, landslides and soil erosion," the study says.
Himalayan states in India have suffered from increased frequency and intensity of landslides and floods
This risk is higher for the Himalayan region compared with other mountainous regions like the Alps and the Rockies in the northern hemisphere, Mohamed Ombadi, the study's lead author, told the BBC.
"That's because there are additional warming-related processes [in the Himalayas] that change wind patterns and storm tracks, leading to an increase in the intensity of storms."
Mountains in the Himalayas, which span India, Bhutan Nepal and Pakistan, hardly have any weather stations, which often leads to a lack of accurate data on precipitation levels.
There are a few stations located in the lower elevations of the mountains but they do not show whether the precipitation recorded is rain or snowfall.
However, a weather station installed at the base camp of Mount Everest showed that 75% of the 245.5mm precipitation on the mountain between 1 June and 10 August this year had fallen as rain. The remaining was snow or a combination of rain and snow.
This is a huge jump from the 32% of rain recorded between June and September in 2022, 43% in 2021 and 41% in 2020.
"We believe the dominance of rain vs snow is a relatively recent phenomenon but do not have longer term data to fully quantify that," said National Geographic explorers Baker Perry and Tom Matthews who were part of the National Geographic and Rolex Perpetual Planet Expeditions that installed the station.
The trauma of living in India's sinking Himalayan town
The changes in precipitation are evident on the mountains of the Himalayan state of Uttarakhand, says Bikram Singh, head of the regional weather office.
"We can definitely say snowfall frequency has decreased and this is usually at elevations below 6,000m. During monsoon, the lower elevations receive heavy rainfall."
The dwindling snowfall and increased rainfall mean that the nature of rivers in the region has changed, says Professor JS Rawat, former head of Kumaun University's geography department.
"There are now lots of flash floods after extreme rainfall and rivers that were once glacier-fed in the region have now turned into rain-fed [water bodies]."
Dozens have been killed in landslides and flash floods in Uttarakhand and Himachal Pradesh this month
Rising temperatures have added to the problem as they have accelerated the melting of Himalayan glaciers. This leads to rapid filling up of glacial lakes that then become prone to overflowing and causing floods. The thinning of glaciers also destabilises mountain slopes.
The Himalayas are estimated to be warming at three times the rate of the global average - and several studies have projected this will lead to substantive increase in rainfall there.
Locals in the states of Uttarakhand and Himachal Pradesh say they have noticed that the frequency and intensity of landslides and floods during the monsoon season have increased.
"Our village Ganai was already threatened by landslides because of increased rainfall on the mountains, so we had to abandon it and move," says Prabhakar Bhatta, 25, a resident of Mayapur village in Uttarakhand's Chamoli district. "But even here we have become homeless."
'Hanging' glacier broke off to trigger India flood
On 14 August, a little before midnight, a huge flash flood hit Mr Bhatta's two-storey house, burying it under debris of rock, silt and mud.
"We managed to survive because we were warned by people in villages at higher elevations that it was raining very heavily and there could be a flash flood coming our way," he says.
Mr Bhatta says his family stayed up that night and fled when they heard "odd sounds".
"My father built the house with his lifetime savings, and now that too is gone," he says. "This region is becoming unliveable."
Locals say the region has become uninhabitable
Experts say that rampant development of infrastructure like road, tunnels and hydropower projects in the ecologically sensitive region also leads to these disasters. Located in a seismic zone as the Himalayas are, they are subject to earthquakes which make matters worse.
The impact of increased rainfall is also visible across the Indian border.
In northern Pakistan, where the Himalayas meet Karakoram and Hindukush mountains, debris flows and flash floods have become increasingly common, officials say.
There were 120 flash floods in the region's Gilgit Baltistan area during the last monsoon - a huge jump from 10-20 years ago, says Kamal Qamar, director general of the regional disaster management authority.
"It's raining in high altitudes at around 4,000m both in summer and winter, when it should have snowed," he says.
Is India-China race to build damaging the Himalayas?
In the eastern Himalayas in Nepal, flash floods and debris flows are destroying vital infrastructure like hydropower and drinking water plants, apart from local settlements, roads and bridges.
According to the country's Independent Power Producers Association, 30 hydropower plants have been damaged in eastern Nepal this monsoon.
Experts say cascading events on Himalayan regions' mountains are also becoming frequent and intense.
That's when an event triggers something else further downstream, says Jakob Steiner, a researcher with the International Centre for Integrated Mountain Development, based in Kathmandu.
"And higher rainfall intensity is often the start or a sub-trigger in these chains."
Thu, August 17, 2023
Increased rain and melting of snow and ice has made the mountain regions more dangerous, a new study finds
Torrential rains and unabated construction are frequently triggering disasters in India's Himalayan region.
But an unusual increase in rainfall is making the terrain even more dangerous.
Landslides and flash floods have already killed dozens in the area this month, burying homes and buildings. Parts of Nepal and Pakistan have also suffered damage.
A new study has found that mountains across the globe, including the Himalayas, are now seeing more rainfall at elevations where it has mostly snowed in the past.
The change has made the mountains more dangerous, scientists say, as increased temperatures not only bring rain but also accelerate melting of snow and ice. The rainwater also loosens the soil resulting in landslides, rockfalls, floods and debris-flows.
"Our findings provide several lines of evidence demonstrating a warming-induced amplification of rainfall extremes at high altitudes, specifically in snow-dominated regions of the Northern Hemisphere," says the study, published in June in the Nature journal.
The finding is consistent with a special report of the Intergovernmental Panel on Climate Change (IPCC) in 2019 which said that snowfall had decreased, at least in part because of higher temperatures, especially at lower elevations of mountain regions.
The Himalayan hazards nobody is monitoring
There are more instances of extreme precipitation events occurring now in the form of rainfall even at a high elevation and in all seasons, says Samuel Morin, executive director of the National Centre for Meteorological Research in France and one of the authors of the special IPCC report.
This is mainly because the zero-degree isotherm, the freezing level at which precipitation falls as snow, has moved to a higher elevation because of global warming
"As a result, these [mountain] regions are regarded as hotspots that are vulnerable to high risk of extreme rainfall events and related hazards of flooding, landslides and soil erosion," the study says.
Himalayan states in India have suffered from increased frequency and intensity of landslides and floods
This risk is higher for the Himalayan region compared with other mountainous regions like the Alps and the Rockies in the northern hemisphere, Mohamed Ombadi, the study's lead author, told the BBC.
"That's because there are additional warming-related processes [in the Himalayas] that change wind patterns and storm tracks, leading to an increase in the intensity of storms."
Mountains in the Himalayas, which span India, Bhutan Nepal and Pakistan, hardly have any weather stations, which often leads to a lack of accurate data on precipitation levels.
There are a few stations located in the lower elevations of the mountains but they do not show whether the precipitation recorded is rain or snowfall.
However, a weather station installed at the base camp of Mount Everest showed that 75% of the 245.5mm precipitation on the mountain between 1 June and 10 August this year had fallen as rain. The remaining was snow or a combination of rain and snow.
This is a huge jump from the 32% of rain recorded between June and September in 2022, 43% in 2021 and 41% in 2020.
"We believe the dominance of rain vs snow is a relatively recent phenomenon but do not have longer term data to fully quantify that," said National Geographic explorers Baker Perry and Tom Matthews who were part of the National Geographic and Rolex Perpetual Planet Expeditions that installed the station.
The trauma of living in India's sinking Himalayan town
The changes in precipitation are evident on the mountains of the Himalayan state of Uttarakhand, says Bikram Singh, head of the regional weather office.
"We can definitely say snowfall frequency has decreased and this is usually at elevations below 6,000m. During monsoon, the lower elevations receive heavy rainfall."
The dwindling snowfall and increased rainfall mean that the nature of rivers in the region has changed, says Professor JS Rawat, former head of Kumaun University's geography department.
"There are now lots of flash floods after extreme rainfall and rivers that were once glacier-fed in the region have now turned into rain-fed [water bodies]."
Dozens have been killed in landslides and flash floods in Uttarakhand and Himachal Pradesh this month
Rising temperatures have added to the problem as they have accelerated the melting of Himalayan glaciers. This leads to rapid filling up of glacial lakes that then become prone to overflowing and causing floods. The thinning of glaciers also destabilises mountain slopes.
The Himalayas are estimated to be warming at three times the rate of the global average - and several studies have projected this will lead to substantive increase in rainfall there.
Locals in the states of Uttarakhand and Himachal Pradesh say they have noticed that the frequency and intensity of landslides and floods during the monsoon season have increased.
"Our village Ganai was already threatened by landslides because of increased rainfall on the mountains, so we had to abandon it and move," says Prabhakar Bhatta, 25, a resident of Mayapur village in Uttarakhand's Chamoli district. "But even here we have become homeless."
'Hanging' glacier broke off to trigger India flood
On 14 August, a little before midnight, a huge flash flood hit Mr Bhatta's two-storey house, burying it under debris of rock, silt and mud.
"We managed to survive because we were warned by people in villages at higher elevations that it was raining very heavily and there could be a flash flood coming our way," he says.
Mr Bhatta says his family stayed up that night and fled when they heard "odd sounds".
"My father built the house with his lifetime savings, and now that too is gone," he says. "This region is becoming unliveable."
Locals say the region has become uninhabitable
Experts say that rampant development of infrastructure like road, tunnels and hydropower projects in the ecologically sensitive region also leads to these disasters. Located in a seismic zone as the Himalayas are, they are subject to earthquakes which make matters worse.
The impact of increased rainfall is also visible across the Indian border.
In northern Pakistan, where the Himalayas meet Karakoram and Hindukush mountains, debris flows and flash floods have become increasingly common, officials say.
There were 120 flash floods in the region's Gilgit Baltistan area during the last monsoon - a huge jump from 10-20 years ago, says Kamal Qamar, director general of the regional disaster management authority.
"It's raining in high altitudes at around 4,000m both in summer and winter, when it should have snowed," he says.
Is India-China race to build damaging the Himalayas?
In the eastern Himalayas in Nepal, flash floods and debris flows are destroying vital infrastructure like hydropower and drinking water plants, apart from local settlements, roads and bridges.
According to the country's Independent Power Producers Association, 30 hydropower plants have been damaged in eastern Nepal this monsoon.
Experts say cascading events on Himalayan regions' mountains are also becoming frequent and intense.
That's when an event triggers something else further downstream, says Jakob Steiner, a researcher with the International Centre for Integrated Mountain Development, based in Kathmandu.
"And higher rainfall intensity is often the start or a sub-trigger in these chains."
As glaciers melt, a new study seeks protection of ecosystems that emerge in their place
JAMEY KEATEN
Updated Thu, August 17, 2023
FILE - A team member of Swiss Federal Institute of Technology glaciologist and head of the Swiss measurement network 'Glamos', Matthias Huss, passes the Rhone Glacier covered by sheets near Goms, Switzerland, on June 16, 2023. A new scientific study suggests the world should start preparing to protect the ecosystems that emerge from under the disappearing ice as warming planet is inevitably causing glaciers to melt. (AP Photo/Matthias Schrader) (ASSOCIATED PRESS)More
GENEVA (AP) — A new scientific study published Thursday suggests the world should start preparing to protect the ecosystems that emerge from under the disappearing ice, as a warming planet is inevitably causing glaciers to melt.
If nothing is done to stop global warming, the world could lose glaciers totaling the size of Finland by 2100. Even a best-case scenario — if the targets of the Paris Agreement to stop climate change are met — foresees glacier shrinkage the size of Nepal, according to the study published in the scientific journal Nature.
The analysis from Swiss and French scientists adds to worries about glacier melt and a growing call to step up efforts to protect the planet from climate change.
In their research, the scientists say humans have grown to live with glaciers for millennia, and the worrying retreat of the ice cover — currently amounting to 10 percent of the Earth’s land surface — will require both action to stop it and adaptation for its impact.
Glaciers play a key role on the planet, by reflecting sunlight or providing fresh water for irrigation, power generation and consumption, says study co-author Jean-Baptiste Bosson, a French-Swiss glacier expert with the National Council for the Protection of Nature in Annecy, France.
He said work is being done to slow down the retreat of glaciers, though it won't be “decisive” in saving them.
“But after the glaciers (melt) not everything is lost,” Bosson said in an interview. “We especially need to protect the nature that will follow the glaciers: we need to protect the forests of tomorrow, the great lakes of tomorrow, the great fjords of tomorrow."
The areas where glaciers once were will be “degraded” when the ice melts, Bosson said, adding that nature should be left to do its work: “There is a chance for ecosystems to rebound if we leave them space and time ... nature itself will find solutions: It will capture carbon, purify fresh water, create habitats for biodiversity."
Glacier retreat hit unprecedented high levels in Europe last year, especially in Switzerland.
The team behind the Nature study analyzed some 210,000 glaciers on Earth, not including the gigantic Greenland and Antarctic ice sheets, and found that glaciers covered some 665,000 square kilometers (257,000 square miles), about the size of Afghanistan, in 2020.
Depending on the different scenarios, which the experts slice up from worst-case to best-case, the world could lose between roughly 149,000 square kilometers (58,000 square miles) to some 339,000 square kilometers (131,000 square miles), by 2100. The team accounts for possible statistical variance. The loss could be much larger.
“Melting glaciers have become icons of climate change. People are mostly worried about the impact glacier melt will have on sea-level rise, seasonal water availability, and geohazards,” said Prof. Ben Marzeion, of the Institute of Geography at Germany’s University of Bremen.
“This study shows that there is more we need to be prepared for. It also shows that we are still in the process of uncovering the multitude of impacts climate change will have,” said Marzeion, who was not involved in the research.
Twila Moon, deputy lead scientist at the U.S. National Snow and Ice Center, laid out the challenges that policymakers will face as landscapes change with glacier retreat.
“There is no question that ice loss around the world is a serious issue, from influencing water availability to raising our sea levels,” Moon, who wasn’t involved in the study, said in an email. “This research highlights another impact — the uncovering of new land as glaciers shrink.”
“Glacier retreat can cause increasing hazards, like the outburst flood that destroyed homes in Juneau earlier this summer, or change water availability for drinking and crops,” Moon wrote. “We must plan ahead while also work hard to reduce heat-trapping gas emissions and limit future damage.”
Bosson says that record high temperatures reached this year in the northern hemisphere are producing worrisome outcomes that could have an even greater impact in the future – though not all data is in yet.
“We try to tell the story of the future of the surfaces today occupied by glaciers on Earth,” he said in a video call from the French Alpine town of Annecy. “Then we ask: Will tomorrow still see big glaciers, or smaller glaciers depending on the climate scenarios?”
JAMEY KEATEN
Updated Thu, August 17, 2023
FILE - A team member of Swiss Federal Institute of Technology glaciologist and head of the Swiss measurement network 'Glamos', Matthias Huss, passes the Rhone Glacier covered by sheets near Goms, Switzerland, on June 16, 2023. A new scientific study suggests the world should start preparing to protect the ecosystems that emerge from under the disappearing ice as warming planet is inevitably causing glaciers to melt. (AP Photo/Matthias Schrader) (ASSOCIATED PRESS)More
GENEVA (AP) — A new scientific study published Thursday suggests the world should start preparing to protect the ecosystems that emerge from under the disappearing ice, as a warming planet is inevitably causing glaciers to melt.
If nothing is done to stop global warming, the world could lose glaciers totaling the size of Finland by 2100. Even a best-case scenario — if the targets of the Paris Agreement to stop climate change are met — foresees glacier shrinkage the size of Nepal, according to the study published in the scientific journal Nature.
The analysis from Swiss and French scientists adds to worries about glacier melt and a growing call to step up efforts to protect the planet from climate change.
In their research, the scientists say humans have grown to live with glaciers for millennia, and the worrying retreat of the ice cover — currently amounting to 10 percent of the Earth’s land surface — will require both action to stop it and adaptation for its impact.
Glaciers play a key role on the planet, by reflecting sunlight or providing fresh water for irrigation, power generation and consumption, says study co-author Jean-Baptiste Bosson, a French-Swiss glacier expert with the National Council for the Protection of Nature in Annecy, France.
He said work is being done to slow down the retreat of glaciers, though it won't be “decisive” in saving them.
“But after the glaciers (melt) not everything is lost,” Bosson said in an interview. “We especially need to protect the nature that will follow the glaciers: we need to protect the forests of tomorrow, the great lakes of tomorrow, the great fjords of tomorrow."
The areas where glaciers once were will be “degraded” when the ice melts, Bosson said, adding that nature should be left to do its work: “There is a chance for ecosystems to rebound if we leave them space and time ... nature itself will find solutions: It will capture carbon, purify fresh water, create habitats for biodiversity."
Glacier retreat hit unprecedented high levels in Europe last year, especially in Switzerland.
The team behind the Nature study analyzed some 210,000 glaciers on Earth, not including the gigantic Greenland and Antarctic ice sheets, and found that glaciers covered some 665,000 square kilometers (257,000 square miles), about the size of Afghanistan, in 2020.
Depending on the different scenarios, which the experts slice up from worst-case to best-case, the world could lose between roughly 149,000 square kilometers (58,000 square miles) to some 339,000 square kilometers (131,000 square miles), by 2100. The team accounts for possible statistical variance. The loss could be much larger.
“Melting glaciers have become icons of climate change. People are mostly worried about the impact glacier melt will have on sea-level rise, seasonal water availability, and geohazards,” said Prof. Ben Marzeion, of the Institute of Geography at Germany’s University of Bremen.
“This study shows that there is more we need to be prepared for. It also shows that we are still in the process of uncovering the multitude of impacts climate change will have,” said Marzeion, who was not involved in the research.
Twila Moon, deputy lead scientist at the U.S. National Snow and Ice Center, laid out the challenges that policymakers will face as landscapes change with glacier retreat.
“There is no question that ice loss around the world is a serious issue, from influencing water availability to raising our sea levels,” Moon, who wasn’t involved in the study, said in an email. “This research highlights another impact — the uncovering of new land as glaciers shrink.”
“Glacier retreat can cause increasing hazards, like the outburst flood that destroyed homes in Juneau earlier this summer, or change water availability for drinking and crops,” Moon wrote. “We must plan ahead while also work hard to reduce heat-trapping gas emissions and limit future damage.”
Bosson says that record high temperatures reached this year in the northern hemisphere are producing worrisome outcomes that could have an even greater impact in the future – though not all data is in yet.
“We try to tell the story of the future of the surfaces today occupied by glaciers on Earth,” he said in a video call from the French Alpine town of Annecy. “Then we ask: Will tomorrow still see big glaciers, or smaller glaciers depending on the climate scenarios?”
More Snow Can Actually Cause Tundra to Thaw Faster, Unleashing Buried Carbon
Yale Environment 360
Thu, August 17, 2023
The International Tundra Experiment at Toolik Lake in Alaska.
Yale Environment 360
Thu, August 17, 2023
The International Tundra Experiment at Toolik Lake in Alaska.
Amanda Young / Toolik Field Station
With climate change, parts of the Arctic are seeing greater snowpack. Paradoxically, a thick blanket of snow can speed the melting of permafrost underneath, releasing buried stores of carbon, new research shows.
The insight comes from a decades-long experiment near Toolik Lake in northern Alaska. Starting in 1994, scientists there began covering a swath of tundra in three to four times the usual amount of snowpack, finding that, as the region warmed, this patch actually thawed faster than other areas. Scientists said the added snow acted like a blanket during the cold months, holding in summer heat while keeping out frigid air.
As permafrost melted, microbes began to consume long-frozen plant matter in the ground, producing carbon dioxide as a byproduct. The patch of tundra with extra insulation became a year-round source of emissions. Even as shrubs began to grow on the once-frozen ground and soak up some carbon dioxide, the emissions from microbes remained greater still, according to the new study, published in AGU Advances.
The new findings, authors write, show that greater snowfall “will cause earlier-than-expected losses of ancient carbon from permafrost and further accelerate climate change.”
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