Himalayas losing glaciers and snow: more hazards in the offing, a new study finds

“As scientists, what worries us the most is the scale at which the glaciers are melting in the Himalayas,” said Jakob F. Steiner, a fellow at the Himalayan University Consortium (HUC). “For instance, there is a glacier in the Himalayas that has been monitored for the longest time. It is almost dead now. What remains is a patch of ice hanging up there. We don’t even call it a glacier anymore because it’s just a piece of ice,” he shared.

The long-term observations and assessments of the cryosphere of the Hindu Kush Himalaya (HKH) by scientists, including Steiner, have culminated in a report titled Water, ice, society and ecosystems in the Hindu Kush Himalaya or the HI-WISE report. Released by Nepal-based International Centre for Integrated Mountain Development (ICIMOD) in June this year, the HI-WISE report follows the HKH Assessment Report (2019), which assessed literature published till 2017, focusing on aspects of climate change, cryosphere, water and biodiversity.

The latest report puts additional focus on the mountain-dependent societies and ecosystems and uncovers the cryosphere-hydrosphere-biosphere-society linkages in the Hindu Kush Himalayan region. Philippus Wester, lead editor and coordinator of the report said that they wanted to broaden the scope of the study by including societies and ecosystems as well. “We know the cryosphere is changing but we don’t fully know what that implies to the mountain-dependent communities and the ecosystems,” Wester said.

The HI-WISE report aims to inform the people of the Hindu Kush Himalaya, as well as decision-makers, practitioners and the global community on the rapidly changing cryosphere in the region and its impacts on water, biodiversity, and societies.

The Himalayas losing glaciers, peak meltwater availability in rivers till 2050

One of the key findings of the assessment is a projected 30%-50% loss in glacier volume by the end of the century at the global warming level between 1.5 degrees Celsius to 2 degrees Celsius. For higher global warming levels, the glacier volume loss is estimated to be 60%-80%. More significantly, the rate of glacier mass loss increased by 65%, from an average of minus 0.17 metres water equivalent (m w.e.) per year for the period 2000-2009 to minus 0.28 m w.e. per year for 2010-2019, notes the report.

Another revelation is that the enigmatic Karakoram range, too, is losing glaciers, making the “Karakoram Anomaly” a thing of the past. Karakoram Anomaly refers to the anomalous growth and stability of glaciers in central Karakoram, in contrast to the retreat of glaciers in other parts.

This rapid glacier melt would result in increased water discharge into the rivers. The report predicts peak water availability in the Indus, the Ganges and other river basins in the Hindu Kush region by mid-century after which there would be a steady decrease of water availability towards 2100. This may have some benefits in the short-term such as plentiful water and fertile riverbeds for agriculture. On the flip side, more extreme weather events like glacier lake outburst floods (GLOFs) that happened in Chamoli or Melamchi are a possibility, said the researchers.

This will have wider ramifications, as the region, called the Water Tower of Asia, is the water source for 16 countries, including India and China, feeding over two billion people living in various river basins. Even the people living downstream are heavily reliant on meltwater originating from mountains for agricultural, domestic, and industrial uses.

Snow cover loss, permafrost thaw make mountain hazards multidimensional

The region is also losing snow cover rapidly. The report suggests that the snow cover days have declined at an average rate of five days per decade with most of the changes at lower elevations. There is also a seasonal shift in the snow cover with a notable decrease during the summer and winter months, as well as a decline from mid-spring through mid-fall.

Steiner told Mongabay-India that the snow loss is perhaps more consequential to life forms than glacier melt. “There is a lot of dependence on snow for various living things, including humans. The temperature is balanced under the snow. If not for it, the region will become hostile; the plants will be exposed to harsh mountain sun in the day and freezing cold like minus 20 degrees Celsius or minus 30 degrees Celsius at night,” he said.

Furthermore, snow melt saturates the slope, and combined with glacier melt, the mountains pose multiple hazards. Warmer temperatures in higher elevations could contribute to ascending tree lines and more organisms moving upwards. This could also lead to cold-dependent life forms facing the threat of dying out, according to Wester.

Thawing permafrost in the Himalayas has been reported to be a cause for impending climate disasters. The invisibility of permafrost continues to be a hurdle in its studies, leaving inadequate literature on its changes.

The report draws on field observations in the Hindu Kush Himalaya and remote sensing to warn that the permafrost cover in the region is declining. “It is visible only to the trained eye. Earlier, we considered the possibility of permafrost thaw. But now when we look at the mountain slopes in India or Pakistan at an elevation where we know permafrost is thawing, we can see the change,” said Steiner.

Permafrost thaw makes surfaces, slopes and infrastructure unstable, making a good case for a change in government policies on large hydropower projects in the region, a debate that has been raging in India for some time. Additionally, permafrost thaw leads to increased sedimentation in rivers which damages dams and turbines, Steiner added.

Ecosystems degrading, societies reaching hard limits for adaptation

The HI-WISE report notes that there is increasing documentation of the cascading effects of cryosphere loss on ecosystems, including ecosystem degradation and changes in species structure and composition. For the societies in the region, the risks posed by cryosphere-related hazards are becoming more unpredictable, and future cryosphere-related disasters will be costlier and deadlier.

The researchers believe that cryosphere changes coupled with erratic rainfall patterns observed in the region is a double whammy for the societies, as is evident from the recent floods and landslides in Himachal Pradesh.

Another key takeaway from the report is that the risk perception of the communities and the adaptation measures taken at the local level are significant in reducing the damages from hazards. The study finds the global warming level of 2 degrees Celsius is the hard limit of adaptation.

“More people and societies are aware and trying to adapt. But the effort is localised and too slow for the pace at which the changes are happening. There is a shortage of attention on the region and funds to deal with these changes,” Wester said.

The report also makes the case for loss and damage stronger for the Himalayan states on global platforms. Scientists also express the need for an economic assessment of the Hindu Kush Himalayan ecosystem so that the impacts of climate change could be assessed more accurately. The region being a shared global asset, the paper calls for regional cooperation on safeguarding the shared heritage and its fragile ecosystems.

 

Banner image: A mountain in Himalaya’s Sagarmatha National Park in Nepal. Photo by Peter Prokosch.