Permafrost melting is emerging as a unique environmental threat in the Kashmir Himalaya. A new study has found that thawing permafrost could affect 193 km of roads, 2,415 households, 903 alpine lakes, and eight hydropower projects in the mountainous region.
Permafrost is any type of ground — soil, sediment, rock, etc. — that has been continuously frozen for at least two years. Most of the permafrost on the earth has been that way for several millennia.
But with global warming, the permafrost is slowly beginning to thaw, with dramatic consequences. Permafrost stores several tonnes of organic carbon. As it melts, the carbon is released into the environment, including in the form of methane, a very potent greenhouse gas and climate pollutant.
The stability of permafrost in the Indian Himalaya is thus of great concern.
The new study, published in Remote Sensing Applications: Society and Environment, was coauthored by researchers from the University of Kashmir and IIT-Bombay.
According to the study, permafrost covers 64.8% of the total geographic area of Jammu & Kashmir (J&K) and Ladakh. Of this 26.7% is continuous permafrost (most of the soil is frozen), 23.8% is discontinuous (more than half of the soil is frozen), and 14.3% is sporadic (intermittent patches of frozen soil).
A ‘crucial’ study
“Region-wise, the Ladakh plateau contains the highest extent (87%) of permafrost, while the foothill plains of Jammu, Shigar Valley, and Siwaliks do not host any permafrost,” the authors wrote in their paper.
The study’s corresponding author Irfan Rashid, assistant professor in the Department of Geoinformatics at the University of Kashmir, Srinagar, said the team analysed weekly satellite data for surface temperatures from 2002 to 2023.
“Over 21 years, we examined over 56 images each year, amounting to a total dataset of 1,176 land surface temperature images,” he said. The data came from a NASA sensor onboard its Terra and Aqua satellites called MODIS. Rashid said “each pixel in [its images] represents an area of 1 sq. km.” He continued: “We analysed approximately 222,236 pixels across J&K and Ladakh. This extensive dataset allowed us to identify areas with consistently frozen temperatures and those where freezing conditions are absent or intermittent.”
Reet Kamal, associate professor in the Department of Civil Engineering at IIT-Ropar, said the study (in which he wasn’t involved) could be a preliminary step in assessing the impact of permafrost degradation.
“It is a crucial study, as permafrost has been largely overlooked, and no similar research has been conducted in this region,” Kamal said. “While some studies exist in Uttarakhand, there is a pressing need for more research to better understand the risks associated with permafrost degradation.”
According to the experts, the primary factor driving permafrost degradation is the rise in surface temperature.
Farooq Ahmad Dar, assistant professor in the Department of Geography and Disaster Management at the University of Kashmir, said that in addition to natural causes, human factors can also affect permafrost. “Activities such as deforestation, land-use change, and wildfires have severe impacts on the permafrost cover and its stability. Vegetation insulates and protects the permafrost from direct solar radiation. Natural processes such as [earthquakes] frequently shake the ground, including permafrost, and cause it to break apart,” he said.
Likewise, he added, activities related to infrastructure development, such as the construction of dams, road-laying, and real-estate development also affected permafrost in the western Himalaya. “It has also been observed that the tourism and associated activities in the region often lead to increased pressure and impact the stability of the permafrost regions,” Dar said.
Uncertainties abound
The study said the risks associated with permafrost thawing will be felt significantly across thousands of glacial lakes in the Indian Himalayan arc.
In J&K itself, the authors identified 332 proglacial lakes, of which 65 have differing (nontrivial) glacial lake outburst flood (GLOF) risks. A proglacial lake is formed when water from a melting glacier collects in a depression in the landscape or when its flow is dammed. The Central Water Commission reported last year that between 2011 and 2024, the coverage of “glacial lakes and other water bodies” in the Himalaya had increased by 33%.
In places with steep glacial landscapes, rapidly moving ice sometimes scours the underlying bedrock, further degrading permafrost. The rock-ice avalanche in Chamoli, Uttarakhand, in February 2021 is an example: the avalanche was triggered by a glacier on a sheer slope where the adjacent rock material was frozen.
The South Lhonak Lake in Sikkim suffered a significant GLOF in October 2023 in similar circumstances. The lake is surrounded by moraines composed primarily of permafrost-laden material. Over time, Rashid said, temperature fluctuations induced slope failure triggered by degraded permafrost.
According to Kamal of IIT-Ropar, permafrost degradation is also likely to adversely affect groundwater and the availability of river water. “Permafrost, in the form of rock glaciers, contributes to river flow, and in some areas, its degradation could affect the base flow of rivers. However, no comprehensive studies have been conducted to accurately identify or quantify these impacts in the Indian context. Therefore making definitive statements on this matter would be premature,” he said.
He added that permafrost “may also pose risks to infrastructure, but without in-depth studies, the extent of potential damage remains uncertain.”
Planning for permafrost
The experts suggested that while existing roads can’t be closed, the construction of future ones should be informed by the presence or absence of permafrost. This could be a long-term strategy to ensure sustainable construction in ecologically fragile areas.
According to Rashid, while environmental impact assessments are conducted for projects like hydroelectric power projects, whether they adequately account for GLOFs and other cryospheric hazards is unclear. “Increased awareness of permafrost-related risks has only emerged following major disasters. Previously, GLOFs were primarily associated with Nepal, but events such as the Kedarnath disaster, the South Lhonak Lake outburst, and incidents in Ladakh have highlighted their broader relevance,” Rashid said.
Dar agreed: to mitigate potential risk, he said it is crucial to bring these findings to the implementation level, particularly in places with permafrost.
“Households in permafrost-rich regions face varying degrees of risk,” he added. “In Ladakh, steep slopes containing permafrost are home to residential settlements. Military infrastructure in Ladakh is at risk, posing concerns for national security. Many strategic roads pass through permafrost zones, and their degradation due to permafrost thaw or mass wasting could have severe implications for connectivity.”
“We mostly rely on satellite remote-sensing to monitor land surface temperatures,” Kamal added. “However, there is currently no in-situ monitoring in these regions. Deploying data loggers in the same catchment areas would allow us to track temperature fluctuations more accurately. These data loggers could also help calibrate satellite data and identify any biases, making permafrost monitoring more precise and reliable.”
Hirra Azmat is a Kashmir-based journalist who writes extensively on science, health, and environment. Her stories have appeared in various local and national publications.
Published – March 25, 2025 05:30 am IST
