New Delhi: A new analysis by Climate Central showed that the three-day extreme heat event over Uttar Pradesh from June 14 to 16 was made at least two times more likely by human-caused climate change.
In Ballia district, the temperature reached 42.2-degrees Celsius on June 16, and at least 34 fatalities occurred over the three-day event.
The analysis uses a metric called Climate Shift Index (CSI), which quantifies the contribution of climate change to daily temperatures. CSI levels over one indicate a clear climate change signal, while levels between two and five mean that climate change made those temperatures between two and five times more likely.
The methodology used to calculate the CSI is based on peer-reviewed science.
In addition to Uttar Pradesh, most locations across India experienced significant CSI levels during this period. The heatwave affected hundreds of millions of people in India.
In Uttar Pradesh, the CSI levels peaked on June 14, decreasing over the following two days.
Certain parts of the state reached the CSI levels of three, indicating temperatures that were made at least three times more likely because of climate change.
The current CSI applies only to temperature. The fact that these extreme temperatures occurred along with high humidity is unusual and contributed to the severity of the event.
This extreme event comes after the deadly humid heatwave in April, which was made more than 30 times more likely by human-caused climate change.
Heatwaves are among the deadliest natural hazards with thousands of people dying from heat-related causes each year and many more suffering other severe health and livelihood consequences.
However, the full impact of a heatwave is often not known until weeks or months later, once death certificates are collected, or after scientists can analyse excess deaths.
As many places lack good record keeping of heat-related deaths, the currently available global mortality figures are likely an underestimate.
Responding to the heatwave, Friederike Otto, a researcher at Imperial College London and co-lead of World Weather Attribution (WWA), said: “We see again and again that climate change dramatically increases the frequency and intensity of heatwaves, one of the deadliest weather events that exist.
“Our most recent WWA study has shown that this has been recognised in India, but implementation of heat action plans is slow. It needs to be an absolute priority adaptation action everywhere.”
Mariam Zachariah, a researcher at Imperial College London and WWA, added: “The combination of extreme heat and humidity is particularly dangerous for humans, even more so in urban contexts where the ‘heat island’ effect can further increase temperatures.
“Unless carbon emissions are rapidly reduced, these life-threatening events will become more frequent and intense.”