Researchers at the Indian Institute of Technology, Gandhinagar published a study of sequential extreme weather events – heatwaves in the summer and extreme rainfall in summer monsoon seasons over the same regions from 1951 to 2020.
What are the key findings of the report?
- Climate change is expected to increase the frequency of extreme weather events like flooding and heatwaves in India manifold
- Sequential weather extremes in India have severe implications on agricultural production, public health and infrastructure.
- The risks will increase because of the warming climate and variability in the El Nino-Southern Oscillation (ENSO) – a recurring climate pattern that changes the temperature of waters in the central and eastern tropical Pacific Oceans.
- Climate mitigation and reduction in vulnerability can minimise the risks associated with the extreme weather events.
- Mega heatwaves that occurred during the summers of 1995 and 1998 severely impacted 20 per cent and 8 per cent of India.
- The area affected by the sequential extremes is higher during the positive phase (El Nino) than the negative phase.
- If the global mean temperature rises above 1.5°C from the preindustrial level, a fraction of the total population and urban area exposed to sequential extremes will increase rapidly.
- By the end of the 21st century (2071-2100), heatwave duration is expected to increase from 3 days in the current climate to 11 days under the lowest emission scenario.
- The duration of heatwaves will increase by 33 days by the end of this century at the highest emissions scenario.
- In India, the number of people exposed to sequential extremes will increase significantly with a rise in global mean temperature above the pre-industrial level. For example, median population exposure increases from 27 percent at 1.5°C to 36 percent and 45 percent at 3 and 4 degree Celsius global warming levels respectively.
- In India, improving of socio-economic livelihood and infrastructure is mitigate the impact of extreme weather events.