What makes Climate Change a factor in Joshimath’s sinking

By Manjori Borkotoky and Aayushi Sharma

The hill town of Joshimath in Uttarakhand has been disrupted in the last few days as residents took to the streets to demand action for the cracks that have developed in their houses. It is reported that about 600 houses across Joshimath have developed cracks and the most-affected families have been evacuated, so far. Some Indian troops have also been relocated from areas surrounding the town, bordering China after cracks appeared in about 20 military installations. Despite the Uttarakhand state government announcing a relief package of ₹45 crore to families in Joshimath, residents have been petitioning in protest against the government to stop all the construction in the town. 

The Supreme Court is set to hear a plea on January 16 that seeks to halt the construction of a hydroelectric project that it says is causing the sinking. 

Joshimath is situated at an altitude of 1890 meters in the Garhwal Himalayas and is an important way station for both pilgrims and trekkers. Around 20,000 people here live on a fragile mountain slope which has been rendered more fragile due to unplanned and indiscriminate development. Land subsidence in Joshimath is primarily due to the National Thermal Power Corporation’s Tapovan Vishnugad Hydro Power Project and is a very grave reminder that people are messing up the environment to an extent that is irreversible.

“Joshimath is a very grave reminder that we are messing up with our environment to an extent that is irreversible,” said Anjal Prakash, Research Director and Adjunct Associate Professor, and Lead Author for IPCC reports, attributing the Joshimath caving incident to the hydropower project. 

“There are two aspects to the Joshimath problem. The first is rampant infrastructure development which is happening in a very fragile ecosystem like the Himalayas and this is happening without much of a planning process in a way where we are able to protect the environment. “Secondly, climate change is a force multiplier. The way climate change is manifesting in some of the hilly states of India is unprecedented. For example, 2021 and 2022 have been years of disaster for Uttarakhand. “There have been numerous climate risk events recorded like high rainfall events triggering landslides. We have to first understand that these areas are very fragile and small changes or disturbances in the ecosystem will lead to grave disasters, which is what we are witnessing in Joshimath,” Prakash said. 

What role do the geographical factors and climate change play in this disastrous event?

“Some of the scientific views have indicated that climate change might have played a role in triggering this geo-hazard in Joshimath located in the Central Himalayas, which is already known to be highly vulnerable to the impact of climate change. There is convincing evidence that the extreme events like very heavy rainfall and glacial movement leading to catastrophic disasters like flash floods and landslides in the Uttarakhand Himalayas in the last two decades bear the signatures of the impact of climate change,” said Dr Partha Jyoti Das, Senior Climate and Environmental Scientist and also Inhouse Consultant of CFC. 

“The magnitude of these disasters and their impact have been, however, magnified by geomorphological fragility combined with the result of the destruction of the natural ecosystems, especially forests and rivers. Therefore, it is highly likely that recent climate-induced hazards have contributed to the present situation. Changes happening to the surface and sub-surface hydrogeological domain and its processes caused by large structural interventions (like the building of dams and tunnels), rapid unplanned urbanization, as well as climate change may also be adding to the causation of the present calamity,” he added. 

According to Uttarakhand State Disaster Management Authority (USDMA), the town is located in an area prone to landslides and the first instance of subsidence in it was reported way back in the 1976 Mishra Commission report. “The area surrounding Joshimath town is filled with a dense layer of overburdened material. This makes the town highly vulnerable to sinking,” said Piyoosh Rautela, executive director USDMA. The USDMA study said that the perennial streams, appreciable snow in the upper reaches, and highly weathered gneissic rocks with low cohesive characteristics make the area prone to landslides.

“Flood events of June 2013 and February 2021 had an adverse impact on the landslide zone with toe erosion and sliding along Ravigram Nala and the Nau Ganga Nala having increased since February 7, 2021, flooding of Rishi Ganga,” the study said. Its reference is to the glacial lake burst that caused a flood, resulting in the loss of 204 lives, mostly migrants working on a hydropower project. The landslide zone was further weakened when Joshimath recorded 190 mm of rainfall in 24 hours on October 17, 2021.

The impact of extreme rainfall events shows that streams in these hilly regions have expanded their channels and changed the course of their flow, thereby inducing more slope instability in an already fragile belt. Unusual weather events in the Uttarakhand Himalayas show an increasing trend. This leads to an increase in the frequencies and magnitude of avalanches, flash floods, (spring season) forest fire events, and landslides. USDMA pointed out reasons for the increase in ground seepage of water from the surface, a probable cause for subsidence. Firstly, on-surface anthropogenic activities cause blockage of natural water drainage systems, which forces water to find newer drainage routes. Secondly, Joshimath town does not have a sewage and wastewater disposal system. Landslides happen due to many reasons like volcanic eruptions, set off by earthquakes, or human activities like mining and long-term change in the climate. But “probably the most common driver we see for landslides worldwide is rainfall,” Ben Leshchinsky, an associate professor in the College of Forestry at Oregon State University, said. “Say you have lots of rain. What that effectively does is reduce the strength of the soil. When that soil strength decreases, it can reach a point where it fails, and naturally just slides away.”

A recent study in the Himalayas indicates that climate change due to anthropogenic sources has led to an increase in the warming of the world’s highest mountain range and the Tibetan Plateau at a rate of 0.2 degrees Celsius per decade during 1951-2014.

Dr Partha Das, Senior Climate and Environmental Scientist and also Inhouse Consultant of CFC stated that India, as a country, has of late shown exemplary ways of dealing with the climate crisis through pragmatic policies and actions that have been appreciated by the world. However, it is ironic that it has not shown enough sensitivity in its approach to developing the Himalayan region when it comes to maintaining a critical balance between the impact of physical interventions for infrastructure expansion and preserving the integrity of the frail landscape which is characteristically delicate in its geological and ecological structure. “Are we not contradicting the objective and spirit of our national policies like the National Mission for Sustaining Himalayan Ecosystem by promoting such reckless, ecologically imprudent, and humanly harmful pursuit of economic development?” asked Dr Das. 

“The incidents of cracks appearing in buildings do not mean that the area has become uninhabitable. Proper soil testing should be carried out, in a scientific manner, to check where the profile of the soil is compact. While planning houses, the reports should be checked and the structure should be specially designed in a way that the movements will not cause them much harm,” said Dr Sushil Kumar, Former Senior Professor, Wadia Institute of Himalayan Geology (WIHG), Dehradun while speaking to CFC India. 

Climate change is evidently leading to more extreme rain events. Rain is why landslide researchers are warning that climate change may make landslides more likely and that we are not prepared for this growing risk. High-elevation areas are undergoing amplified warming at a rate of about 0.5 °C per decade. Most of the areas in the Himalayan region, except the high-elevation Karakoram Himalayas, experienced glacier retreat and a significant decline in wintertime snowfall in recent decades.