The heat stress of Kolkata and Delhi has been mentioned in a global report published on the sidelines of global climate negotiation in Belém on Tuesday.
The report, prepared by the United Nations Environment Programme (UNEP), finds that cooling demand could get tripled by 2050 in a business-as-usual scenario, driven by increases in population and wealth. It adds that the effects of pollution and inefficient cooling are being exacerbated by extreme heat events and for low-income households.
The report claims that the levels cooling-related greenhouse gas emissions in 2022 would double by 2050, pushing cooling emissions to an estimated 7.2 billion tons. This despite efforts to improve energy efficiency, phase down climate-warming refrigerants and overwhelm power grids during peak load.
“Cooling’s climate challenge is two-sided: to expand affordable, sustainable cooling approaches for adaptation, while cutting the energy and carbon footprint of cooling for mitigation,” said Inger Andersen, under-secretary-general of the United Nations and executive director of the United Nations Environment Programme to The Plurals on the sidelines of the launch.
The report, a copy of which is with the portal, says that in 2022, greenhouse emissions from refrigeration and air-conditioning equipment totalled an estimated 4.1 billion tons of carbon dioxide equivalent globally, of which roughly one-third was from refrigerant leakage and two-thirds from energy use.
The report suggests adopting a ‘Sustainable Cooling Pathway’, which could reduce emissions to 64 per cent at 2.6 billion tons, below the levels expected in 2050.
Heat stress threat of India highlighted
India’s heat problems and programmes have been referred to about 10 times in the report, underlining the country’s risk from the sector.
“Delhi and Kolkata in India face heightened heat-related morbidity and mortality, lower labour productivity, and stressed water systems due to extreme heat and infrastructure challenges,” the report observes.
The 2024 heatwave saw Delhi-based hospitals reporting 275 deaths by late June that year, though the actual number may be significantly higher.
According to available data, extreme heat currently results in a 4 per cent loss of Delhi’s total economic output due to reduced worker productivity, while the figure is projected to increase to 5 per cent by 2050. However, despite accounting for only 9 per cent of Delhi’s economic output, construction workers bear one-third of the city’s heat-related economic losses as they work mainly outdoors. A study found that during the May–June 2019 heatwave, informal workers in Delhi experienced a 40 per cent reduction in earnings compared to non-heatwave days.
“Heat stress in Delhi is exacerbated by high levels of air pollution, which worsens health outcomes. For children in poverty, this combination of heat and air pollution is estimated to reduce life expectancy by up to five years compared to wealthier counterparts,” says an expert.
“During May 2024, Delhi’s electricity demand surged beyond 8,300 megawatts due to extreme heat and heavy air-conditioning use, pushing the grid to its limits and triggering blackouts in some areas,” reads the report.
Kolkata, which is projected to reach near 50-degree maximum temperature by 2080 according to the latest IPCC report, is projected to see the heat surging over 35 degrees Celsius on days comprising half of the total days in a year by the same time. The UN report also pointed out that the rise of average temperature in Kolkata was highest – 2.67 degrees Celsius — during 1958-2018 among 20 cities and regions of the world that the report studied.
A study by the Delhi-based environment thinktank Centre for Science and Environment shows that no part of Kolkata has been spared from the effects of the rising degrees, with close to half of the wards within the Kolkata Municipal Corporation limits falling in the category of either ‘high’ or ‘moderate’ heat vulnerability.
The analysis, a copy of which is with this correspondent, attributes the rising heat in Kolkata to ‘shrinking’ green verges and water bodies.
“Heatwaves are major threats to any city in India with high population and Kolkata is no exception. Kolkata needs a heat action plan at the earliest,” said Subimal Ghosh, a climate scientist at the Indian Institute of Technology, Mumbai, and also a lead IPCC report author.
Indian efforts lauded
The UN report, while providing a poser on India’s heat stress risk, however chose to mention a few efforts that are trying to counter the trend.
“Government efforts such as India’s National Disaster Management Authority aim to minimise heat-related mortality by prioritising passive cooling in schools, urban areas, and affordable housing, (while) farmers in Bihar, India, are deploying sustainable cold chain systems to reduce post-harvest losses and stabilize incomes,” reads the report.
The report mentioned the Infosys Crescent building located in Bengaluru that was completed recently. It uses a radiant cooling system paired with a dedicated outdoor air system, delivering high indoor air quality and superior cooling capacity.
The field trials in Palava City at Thane district of Maharashtra were referred to. The results: “super-efficient air conditioners reduced energy use by 60 percent, halved peak demand, and maintained comfort access across both temperature and humidity.”
The report spoke about India’s “urgency of integrating passive cooling strategies” as extreme heat events have led to surges in electricity demand and grid instability, and about the “Million Cool Roofs Challenge in India” that promotes local champions to implement cool roof solutions for vulnerable communities.
According to the report, Jodhpur, in Rajasthan, unveiled its first net-zero cooling station in 2024, showcasing sustainable cooling solutions.