More Delhi areas at risk of facing heatwaves: Study

While the air temperature is the actual temperature, HI also factors in high humidity to give a “real feel” of the temperature and how hot it actually feels to the human body

High temperatures—which have risen up to 6-7 degrees above normal over the years—recorded in certain pockets of Delhi in summers are putting all of the Capital at risk of heatwaves, new research carried out by the universities of Cambridge and Yale has found. The research found that this can also negatively impact Delhi’s sustainable development goals (SDGs) progress.

A real feel temperature of 26°–32°C will likely cause fatigue in many people, while 32°–40°C is widely associated with sunstroke, and 40°–54°C with heatstroke. (ANI)

Researchers calculated the heat index (HI) for Delhi and the rest of India recorded last April and also looked at the climate vulnerability index (CVI) for the study. States such as Punjab, Haryana, and Delhi were found to have the highest CVI based on high air temperatures and HI readings, finding these “temperature anomalies” to be 6-7 degrees above what the India Meteorological Department (IMD) considers normal for that time of the year.

The study, which was released on Wednesday and led by Ramit Debnath from Cambridge university, also found that while the Delhi government has identified only the south and northeast districts as most vulnerable to climate change, all districts in Delhi recorded dangerous air temperature and HI levels, with the highest readings recorded in the New Delhi area, along with some parts of the south district.

While the air temperature is the actual temperature, HI also factors in high humidity to give a “real feel” of the temperature and how hot it actually feels to the human body. Heat index is derived from the measured ambient temperature and humidity (absolute or relative). A real feel temperature of 26°–32°C will likely cause fatigue in many people, while 32°–40°C is widely associated with sunstroke, and 40°–54°C with heatstroke.

“The Delhi government’s assessment shows that south and northeast Delhi, which are also the most affluent areas, are most vulnerable to climate change (crisis) impact. However, our estimation shows that 100% of the city is at dangerous HI levels. In addition, by downscaling the HI to the district level, results show that even low climate-vulnerable areas in Delhi have high heatwave risks. This is concerning as the current heat action plans are designed and implemented according to the Delhi government’s vulnerability assessment, which does not include HI estimations,” said the study, which was co-authored by Ronita Bardhan and Michele L Bell.

“In addition, developments in central, east, west, and northeast districts can further elevate the local HI risk through heat island formation,” it added.

The study said in order to remedy the problem, Delhi needs to look at parameters including avoiding overcrowding in high HI areas, and improving access to electricity, water, and health care.

“Our results showed that Delhi lies in the 6-7˚C temperature anomaly zone, with HI levels that are in the danger category. The regional analysis also shows that Delhi’s urban sustainability is severely challenged as its current district-level climate change vulnerability measurements (through State Action Plans on Climate Change (crisis)) do not factor in heatwave impacts,” said Debnath in his research.

“Some of the critical variables in Delhi that will aggravate heat-related vulnerabilities are concentration of slum population and overcrowding in high HI areas, lack of access to basic amenities such as electricity, water, and sanitation, non-availability of immediate health care and health insurance, poor housing and dirty cooking fuel (traditional biomass, kerosene, and coal),” he added.

The researchers said their findings were also consistent with the SAPCC’s vulnerability assessment which found affluent areas to be high-risk areas too, as low-income groups are often known to live near high-income societies.

“In Delhi, most slum settlements and affluent neighbourhoods coexist and these high temperatures will have unprecedented consequences on the low-income population. Delhi also has high-level construction activities, mostly involving a low-income labour force, which is then at severe risk from heatwave impacts,” the research said.

Anumita Roychowdhury, executive director, research and advocacy at the Centre for Science and Environment (CSE), said the “heat island” is becoming a prominent aspect of urban cities, particularly Delhi, making safeguards against climate change and heat even more important. “We need to look at an action plan that improves greening, protects water bodies, reduces the traffic intensity and also looks to improve thermal comfort in buildings,” she said.