As a sweltering heatwave grips Northern India, Delhi has found itself at the epicenter of an alarming surge in temperatures. On May 29, newspaper headlines screamed of 52.9 degree Celsius at Mungeshpur in north-west Delhi, raising concerns with climate change becoming the common refrain.

Though the India Meteorological Department (IMD) later attributed it to sensor malfunction at the automatic weather station, the fact that temperatures in the capital have been hovering around 50 degree C is enough of a warning.

The maximum temperature across Delhi NCR have varied from 45.2 degrees Celsius to 49.9 degrees Celsius this season. Several factors have contributed to the high temperatures, including lack of rain and hot westerly winds from Rajasthan.

The factors

Temperatures in urban areas like Delhi can vary significantly due to both natural and anthropogenic factors. Areas with high concentrations of pavements, buildings, and roads experience higher temperatures because these surfaces provide less shade and moisture, leading to increased heat. Concrete, which can hold nearly 2,000 times as much heat as an equivalent volume of air, contributes to warmer temperatures.

Densely populated areas with narrow streets and tall buildings obstruct natural wind flows, preventing heat dissipation. Additionally, heavy use of air conditioners in shopping malls and residential areas results in localized higher temperatures due to the heat they release.

The warming over India is less pronounced than the global average. Annual mean temperatures in India have risen by about 0.7 degree Celsius compared to 1900 levels, significantly lower than the rise (1.59 degrees) for average land temperatures worldwide.

However, heatwaves in India have become more severe, with such conditions found even in February 2023, a winter month for which heatwave thresholds are not defined.

The human cost

The extreme temperatures have strained the city’s electricity grid and raised concerns about water rationing. Hospitals have reported an uptick in heatstroke cases, and the city has witnessed a rise in related fatalities.

Moreover, construction workers and other outdoor labourers face heightened risks, prompting the authorities to implement measures such as providing water at bus stands and considering paid leave during peak heat hours.

The extreme weather has an economic impact due to disruption of daily life and commerce.

Scientists and climate experts have long warned that such extreme weather events are likely to become more frequent and intense due to human-induced climate change. The past year has been the hottest ever recorded on the planet. This global trend underscores the urgency for comprehensive climate action and adaptation strategies.

Delhi’s recent experience serves as a stark reminder of the realities of climate change and the urgent need for robust infrastructure and emergency preparedness. The unprecedented temperature surge in Delhi is not just an isolated weather anomaly but a clarion call for climate resilience and action.

As we navigate this new climate reality, it is imperative to prioritize sustainable practices and policies that can help mitigate the effects of global warming and protect vulnerable communities.

The writer is Associate Fellow, NCAER