Climate conundrum: Frequency of summer heatwaves over India may quadruple by end of 21st Century

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With every year that goes by, Indian summers are becoming increasingly unbearable and it seems that things are only set to worsen with time. As per a climate assessment report by the Ministry of Earth Sciences (MoES), the average temperature over India is projected to rise by approximately 4.4°C relative to the recent past (1976–2005 average).

During the period from 1901 to 2018, the country's average temperature has gone up by around 0.7°C, largely on account of the warming due to greenhouse gas (GHG) emissions. The report projects the frequency of summer (April–June) heatwaves over India to increase four-fold by the end of the 21st Century, as compared to the 1976-2005 baseline period.

"The average duration of heatwave events is also projected to approximately double, but with a substantial spread among models," the report said.

The report notes that if greenhouse gases continue to be emitted at the current levels, the global average temperature is likely to rise by nearly 5°C or more by the end of this century.

An increase in average temperature, a drop in monsoon precipitation, a rise in extreme temperature and rainfall events, droughts and sea levels, and an increase in the intensity of severe cyclones, alongside other changes in the monsoon system – these are some of the climatic changes the country has borne witness to since the mid-20th Century.

According to the report, there is compelling scientific evidence to show that human activities have influenced these changes in regional climate, a phenomenon that is expected "to continue apace during the 21st Century".

Rapid changes in climatic conditions placing resources under stress

The impact of such rapid changes in India's climate could be far-reaching, placing "increasing stress on the country's natural ecosystems, agricultural output, and freshwater resources, while also causing escalating damage to infrastructure". This could spell disaster for the country's biodiversity, food, water and energy security, and public health.

The rising temperatures would lead to an increase in demand for energy to meet the demand for space cooling. This, if met by thermal power, would, in turn, lead to higher GHG emissions and thus, to global warming.

The dependence on thermal power for the rising energy demand would again intensify the stress on the country's fast-depleting freshwater sources, as thermal power plants require a substantial amount of water for cooling during the process of electricity generation.

This is only one of the many examples of the vicious cycles of interdependence between the ecological systems and the energy infrastructure.

Changes in rainfall patterns and increased instances of floods, droughts

Several studies cited in the report have shown that the frequency of droughts as well as floods in India has increased since the 1950s. These trends, the report notes, are particularly seen "over central parts of the Indian subcontinent during the south-west (SW) monsoon, and southern peninsular India during the north-east (NE) monsoon".

"India experienced an increase in intensity and percentage of area affected by moderate droughts along with frequent occurrence of multi-year droughts during recent decades," the report said.

The report cites several studies that state that an "increase in extreme precipitation events in a warming environment could likely increase the flood risk over the Indian subcontinent".