CSTEP Study: Prepare for warmer temperature in Jharkhand

Jamshedpur, March 22: A study by the Center for Study of Science, Technology and Policy (CSTEP)—a Bangalore-based think tank—on the climate of eastern India underscores the need for climate risk mapping and climate action. The study ‘District-Level Changes in Climate: Historical Climate and Climate Change Projections for the Eastern States of India’ projects changes in temperature and rainfall patterns in Bihar, Jharkhand, Odisha, and West Bengal—the eastern states of India—over the next three decades compared to the historical period (1990–2019). It analysed two representative scenarios: moderate emissions (RCP 4.5) and high emissions (RCP 8.5).

Climate change projections by CSTEP indicate an overall warming of both summer and winter minimum temperatures, an increase in the number of rainy days (>2.5 mm rainfall/day), and an increase in the number of heavy rainfall events across almost all the districts of the eastern states.

The number of rainy days is projected to increase in the 2030s in all eastern Indian districts compared to the historical period. The increase is by 1 to 11 days under the RCP 4.5 scenario, with the maximum increase projected in West Bengal and a minimum increase projected in Odisha. The increase is by 1 to 15 days under the RCP 8.5 scenario, with the maximum increase projected in West Bengal.

An increase in high-intensity (51–100 mm/day) and very high-intensity (>100 mm/day) rainfall events is projected in the 2030s across a majority of the districts of eastern India compared to the historical period. The increase in high-intensity rainfall events per annum is by one to three events under the RCP 4.5 scenario and one to four events under the RCP 8.5 scenario.

A decline in rainfall deficient years is projected in the 2030s across a majority of the districts of eastern India compared to the historical period. The decline in rainfall deficient years is by 1 to 6 years out of 30 years under both RCP 4.5 and RCP 8.5 scenarios. The highest decline in rainfall deficient years is projected in Odisha.

These changes, particularly the increase in heavy rainfall events, have implications on the amount of water in rivers, streams, and lakes and the replenishment of groundwater—which translates to water available for irrigation and drinking purposes. The climate projections indicate that conditions will become worse in the eastern Indian states, which are flood-prone. Given that droughts have also been witnessed by these states in the past, it is imperative to integrate climate information into planning and decision-making so as to climate-proof the districts of eastern India from floods and droughts. Cohesive planning that is cognizant of changes in climate will not only climate-proof investments but also buffer loss of lives, livelihoods, and infrastructure from extreme climate events.