- Glacial lake outburst floods, have become increasingly common as global warming causes glaciers to retreat, releasing huge amounts of meltwater in a matter of years.
- The accelerating losses in the planet’s snow and ice regions, known as the cryosphere, will result in vastly higher impacts on billions of people’s livelihood and cost to the global economy.
- The 2024 State of the Cryosphere report highlights that without significant emission reductions, rising global temperatures will lead to irreversible impacts.
At around the midnight of October 4, 2023, people in Chungthang, a small town in northern Sikkim in the Indian Himalayas, woke up to a frightening rumble amid torrential rainfall. Within minutes, a massive onrush of water, mud and boulders swept through the town, washing away homes and destroying a dam on the Teesta river.
The flash flood was caused when a lake fed by the Lhonak glacier burst its banks after a cloudburst on October 3-4. Water levels downstream in the Teesta rose by as much as 15-20 feet, causing havoc in Sikkim and neighbouring West Bengal, and inundating hundreds of villages in Bangladesh. More than 100 people died in India and property damage was counted in millions of dollars.
Such extreme weather events, known as glacial lake outburst floods, have become increasingly common as global warming causes glaciers to retreat, releasing huge amounts of meltwater in a matter of years. Just a year earlier, torrential monsoon rains and melting glaciers after severe heatwaves in Pakistan killed nearly 2,000 people and caused economic damages worth $15.2 billion between June and October 2022, according to an assessment by the World Bank.
Scientists have been for years sounding the alarm on such disasters due to human-induced climate change. The accelerating losses in the planet’s snow and ice regions, known as the cryosphere, will result in vastly higher impacts on billions of people’s livelihood and cost to the global economy, they have been saying.
The point was once again driven home through the State of the Cryosphere 2024 report, subtitled Lost Ice, Global Damage, released this week at the annual UN climate summit being held this year in Baku, Azerbaijan’s capital, from November 11-22.
No negotiating with melting point of ice
“We cannot negotiate with the melting point of ice,” said the report coordinated by the International Cryosphere Climate Initiative, a global network of over 50 glaciologists and climatologists formed in 2009, whose work focuses on the three major areas of the cryosphere – the Arctic, the Antarctic and high mountain regions such as the Himalayas and the Andes.
Climate policies currently in place around the world are projected to result in about 2.7°C warming above preindustrial levels by the end of this century, according to Climate Tracker, an independent scientific project. The voluntary commitments that nations have made to cut emissions are insufficient to prevent overshoot of 1.5°C, a target set by the 2015 Paris agreement that has been ratified by most nations that are members of the United Nations Framework Convention on Climate Change.
However, a slower transition away from heat-trapping fossil fuels, agreed upon at the 2023 summit in Dubai, would lock in widespread future loss and damage from the cryosphere for decades and centuries, with adaptation needs far higher and more expensive where still technically feasible, the latest cryosphere report said.
Many ice sheet scientists now say they believe that exceeding even 1.5°C will be sufficient to melt large parts of Greenland and west Antarctica, and potentially vulnerable portions of east Antarctica, generating inexorable sea level rise that would exceed 10 metres in the coming centuries, even if air temperatures are later decreased, the report said.
“We must amplify the message of the disappearing cryosphere due to accelerated warming,” said Jonas Gahr Støre, Prime Minister of Norway, which now chairs the Arctic Council. “This would impact ecosystems and communities worldwide.”
Unstoppable sea level rise
The pace of this long-term, unstoppable sea level rise will pose major long-term persistent challenges for all coastal regions and result in widespread loss and damage of critical infrastructure because about 75 percent of all cities with more than 5 million people are at below 10 metre elevation. It would also severely impact farming and the livelihoods of all those who depend upon these at-risk regions, the Cryosphere Report states.
Even a 2°C rise in global average temperature will lead to escalating loss and damage throughout this century, well beyond limits of adaptation for many mountain and downstream communities. Nearly all tropical and mid-latitude glaciers would vanish and critically important high mountain Asian glaciers such as those in the Himalayas losing around 50 percent of their ice.
Catastrophic hazard events seen today, such as glacial lake outburst floods and landslides, will increase in frequency and scale. The risks are particularly high in Asia, where outburst floods can wash away infrastructure and cities within hours with little warning, as was seen most recently in Sikkim.
Severe and potentially permanent changes to the water cycle due to loss of snowpack and ice runoff during the warm summer growing season will impact food, energy and water security. “As much as 40 percent of Pakistan was flooded in 2022 due to glacial lake outburst floods and flash floods and we lost half of the country’s harvest,” said Ahmed Irfan Aslam, Pakistan’s minister of climate change.
“The Hindu Kush Himalayas are the largest cryosphere outside the poles and we need to take action urgently,” he urged. Cited as one of the costliest natural disasters in world history, the 2022 floods left Pakistan hugely indebted. It had to also divert funds for disaster relief that would have otherwise been utilised for essential services such as public health and education.
“We know what is happening and why it is happening,” pointed out Pema Gyamtsho, director general at the International Centre for Integrated Mountain Development. The Hindu Kush Himalayas host 54,000 glaciers and is home to 240 million people. “The benefits of glaciers and snowmelt flow far beyond mountain communities and impact over a billion people downstream in multiple countries.” The consequences of inaction are too terrifying to contemplate, the chief of the research organisation said.
Cryosphere warming faster than elsewhere
Some of the sea level rise is already locked in and the rate of rise is now twice as fast than in the past 30 years. “The cryosphere is warming faster than elsewhere in the world,” warned James Kirkham, a glaciologist working for the British Antarctic Survey. “A runaway loss of ice would lead to irreversible sea level rise.”
If the current rise of carbon emissions continues, the world would be warmer by around 3.5°C. In such a situation, ice loss from Greenland and west Antarctic will become extremely rapid, the report said. Catastrophic and cascading impacts from glacier and snow loss are associated with these levels of rapid warming.
Some vulnerable mountain and downstream communities could experience non-survivable conditions by the middle of the century due to loss of seasonal water availability, or destructive floods from which they would be unable to recover, they warned. Over time, many of the largest glaciers in high mountain Asia and Alaska are unlikely to survive. Snowpack will become unreliable, with rain falling at higher elevations and more frequently throughout the year, when snow would otherwise be expected.
“We are not talking about the distant future. The impacts of cryosphere loss are already felt by millions,” Kirkham said. “It is terrifying what is happening in the cryosphere” said Heidi Sevestre, a glaciologist with the Arctic Monitoring and Assessment Programme. “How many lives will be lost before we take action?”
Thawing permafrost
Another area of critical concern is permafrost, a combination of soil, rocks and sand that are bound together by ice that stays frozen through the year. At the current levels of rapid warming, much of Arctic permafrost and nearly all mountain permafrost such as those in Tibet and the higher reaches of the Himalayas will thaw, producing annual carbon emissions by the end of this century that would be on par with China’s annual emissions today, which would start a vicious cycle of accelerating global heating.
Communities that live in these areas such as Inuits (earlier known as Eskimos) and Tibetans, stand to permanently lose their way of life and livelihoods, the report said. Since permafrost also locks in organic matter and, when it thaws, it releases copious amounts of methane, a short-lived greenhouse gas that is 80 times more potent than carbon dioxide in terms of warming the climate system.
“It is worrying that the thawing of permafrost is leading to ecosystem destruction and habitat loss,” said Maisa Rojas, environment minister of Chile, home to the Andes mountain range, the highest in the Americas.
Lives are already changing in Greenland, where unstable sea ice and thawing permafrost are making it dangerous for traditional hunting and fishing activities, according to Sara Orwig, an Innuit author and human rights activist. “We are the people of the cryosphere and our rights must be respected,” she said.
There is unanimity among scientists, policy campaigners and climate activists that the only way to save the frozen parts of the world is to rein in planet-warming emissions caused by the burning of fossil fuels. “Climate change cannot be tackled without protecting the cryosphere,” said Dasho Karma Tshering, secretary at Bhutan’s ministry of energy and natural resources. “It is our duty to protect our frozen heritage.”
Banner image: A NASA image from July 12, 2011, shows the Arctic’s sea ice during summer melt, revealing a landscape of melt ponds—freshwater pools that form in depressions on the ice surface. Researchers on the ICESCAPE mission are studying how these melt ponds affect the Arctic’s ocean chemistry, plankton growth, and sunlight penetration, as well as the impact of warming on the region. Image by NASA Goddard Space Flight Center via Wikimedia Commons (CC BY 2.0).
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