Unplanned infra work to climate crisis: Why the hills are reeling

The images are frightening - part of a hillside in Kullu coming down, along with several buildings, all fortunately evacuated in anticipation of just such an eventuality.

- Jayashree Nandi

The immediate cause of this was extreme weather - just as it was earlier this month. In the second week of August, the monsoon trough moved north of its normal position to the Himalayan foothills, triggering heavy rainfall, landslides, and flash floods that damaged buildings, bridges, roads, and other infrastructure in the hill states of Himachal Pradesh and Uttarakhand, leaving 238 and 84 dead since June, respectively.

On August 18 and 19, the trough temporarily moved southwards before moving to the north of its normal position again. Whenever it shifts north, rainfall is concentrated over the Himalayan states and northeast India while the plains remain largely dry.

This is the third time the region is witnessing weather-driven carnage this season. Earlier in July, an interaction between a western disturbance and the trough led to extremely heavy rainfall.

But there are larger underlying causes: the climate crisis; the fact that the Himalayas are relatively young, and still geologically active; and unconsidered, unplanned (and sometimes illegal) development. The impact of the climate crisis on temperatures in Himachal Pradesh and Uttarakhand is also significant with over 1°C warming compared to the longterm average. Himachal Pradesh's average annual mean land surface temperature during 2022 was 1.2°C warmer than its long-period average for the period 1981-2010.

Then there is the rain.