Heatwaves have multiple and cascading impacts not just on human health, but also on ecosystems, agriculture, water and energy supplies and key sectors of economy.
India has been experiencing higher temperatures that arrive earlier and stay for longer, according to the World Bank Report titled, ‘Climate Investment Opportunities in India’s Cooling Sector’ released during the two-day ‘India Climate and Development Partners’ Meet’ on December 07, 2022, organised by the World Bank and the Kerala government. The report said that India would soon become one of the first nations in the world to experience severe heatwaves that would break the human survivability limit.
The Human Survivability Limit refers to the rule of thumb which states that humans can survive three minutes without air, three days without water, and three weeks without food. In some extraordinary cases, some have survived up to nine days without water.
Heatwave in India and its Effect on Indian Economy
India was gripped by an early spring heatwave in April 2022 bringing the country to a standstill. The temperature in New Delhi was recorded 46 °C in April 2022. Even the month of March 2022 had witnessed extraordinary rise in temperatures.
According to the report, the rising temperatures across India could hamper the economic productivity. Almost 75 per cent or about 380 million people of India’s workforce depend on heat-exposed labour. Many a time, they have to work in potentially life-threatening temperatures. If this condition persists then by 2030, India may account for 34 million of the projected 80 million global job losses due to heat stress associated productivity decline.
India has showed the largest heat exposure impacts on heavy labour among South Asian countries, with more than 101 billion hours lost in a year. An analysis by the global management consulting firm, McKinsey & Company, has shown that lost labour from rising heat and humidity could put up to 4.5 per cent of India’s GDP. This is approximately US$ 150–250 billion—at risk by the end of this decade.
Heatwave and IMD’s Criteria for Heatwaves
Qualitatively, heatwave is a condition of air temperature which becomes fatal to human body when exposed, while quantitatively, it is defined based on the temperature thresholds over a region in terms of actual temperature or its departure from normal. In certain countries, it is defined in terms of the heat index based on temperature and relative humidity or based on extreme percentile of the temperatures.
The Indian Meteorological Department (IMD) has given following criteria for heatwaves—
- Heatwave need not be considered till maximum temperature of a station reaches at least 40 °C for plains and 30 °C for hilly areas, and 37 °C for coastal areas.
- When normal maximum temperature of a station is less than or equal to 40 °C heatwave departure from normal is 7 °C or more.
- When normal maximum temperature of a station is more than 40 °C heatwave departure from normal is 4 °C to 5 °C, severe heatwave departure from normal is 6 °C or more.
- When actual maximum temperature remains 45 °C or more irrespective of normal maximum temperature, heatwave should be declared.
The report also stated that in August 2021, the Sixth Assessment Report of the Inter-governmental Panel on Climate Change (IPCC) had warned that the Indian subcontinent would suffer more frequent and intense heatwaves over the coming decade. The G20 Climate Risk Atlas also had warned in 2021 that heatwaves across India were likely to last 25 times longer by 2036–65 if carbon emissions remain high, as in the IPCC’s worst-case emission scenario.
Effect of Heatwave on Food and Public Health
India’s long-term food security and public health security depend on a reliable cold-chain network. An effective system of cold chain which works at every step of the way is required for transporting food and pharmaceutical goods across India.
India is the third largest producer of pharmaceuticals in the world. A single temperature lapse in the journey could break the cold chain, spoiling fresh produce and weakening the potency of vaccines. Pre-COVID-19, India had lost almost 20 per cent of temperature-sensitive medical products and 25 per cent of vaccines due to broken cold chains, leading to a loss of about US$ 313 million a year.
According to the report, with only four per cent of fresh produce in India covered by cold chain facilities, an annual estimated food loss of about US$ 13 billion occurred.
It has also been predicted that heatwave situation in India could break the human survivability limit. The recent heatwave supports what many climate scientists have been cautioning about with reference to rising temperatures across South Asia.
With temperature rise across India, the demand for cooling is also set to increase. Air-conditioning would not be affordable by all, as about two-thirds of the population live on an earning which is less than two US dollar a day. The analysis presented in the India Cooling Action Plan (ICAP) states that only eight per cent of Indian households own air-conditioning units.
Though electric fans would help in providing some relief from the heatwave, the poor and marginalised communities have not been able to afford the same. Consequently, many poor and marginalised communities across India are more vulnerable to extreme heat, living in inadequately ventilated, hot and crowded homes without proper access to cooling.
The health impacts of heatwaves typically include dehydration, heat cramps, heat exhaustion and/or heat stroke.
Measures to Combat Heatwaves
In view of the above, it is clear that the adverse impacts of heatwaves cannot be reduced without effective disaster adaptation strategies and more robust disaster management policies, especially in heatwave zones. The government must prioritise preparing a long-term action plan to safeguard human lives, livestock, and wildlife.
In this respect, the following steps can be mentioned:
- Implementing effectively the Sendai Framework for Disaster Risk Reduction 2015-30 with the State playing a leading role and sharing responsibility with other stakeholders
- Disseminating public awareness through print, electronic, and social media, providing heat-proof shelter facilities in heatwave-prone areas during summer, facilitating access to public drinking water, and afforestation programmes in urban and rural areas
- Installing improved early warning systems that communicate heatwave threats, recommend different preventative measures, and constrain disaster impacts
- Implementing National Action Plan for Climate Change (NAPCC) in true spirit for inclusive growth and ecological sustainability
- Taking into account nature-based solutions in a way that is ethical and promotes intergenerational justice
- Recognising heatwaves as a major disaster
- Declaring heatwaves as a natural disaster in order to help the state and district administration prepare a heatwave action plan at the regional level
- Issuing clear guidelines regarding when to shut schools or how long one should stay outdoors if unavoidable
- Creating naturally ventilated buildings as a vital alternative to address the urban heat for residential and commercial buildings
- Replacing dark roofs with lighter and more reflective materials
- Adopting climate-resilient crops, and making provisions for insurance against crop loss and mixed cropping
India’s Efforts to Combat Heatwaves
In 2016, the NDMA drew up the first national guidelines for heatwaves titled ‘Preparation of Action Plan–Prevention and Management of Heat Wave’. These guidelines were twice revised, first in 2017 and then in 2019. Recommendations were made for more specific actions, based on scientific inputs derived from various research papers, reports, and best practices in heatwave assessment and mapping techniques. The revisions in 2019 included a new section, ‘Built Environment’. The revisions also focused on short-term, medium-term, and long-term measures for heatwave risk reduction.
The guidelines on heatwave clearly mention the roles and responsibilities of the central and state government agencies, district administrations, local self-governments, NGOs, civil society organisations, and other stakeholders in a matrix format.
Consequently, some 17 heatwave-prone states prepared their heatwave action plans between 2015 and 2019. Besides, over 120 districts or cities from 14 states also prepared their own action plans, which help the state governments to develop measures and strategies for heatwave assessment, forecast, preparedness, and mitigation through coordinated efforts with multiple agencies.
The NDMA also conducted a preliminary study to estimate the temperature threshold for 103 Indian cities for heatwave conditions, and the resulting report was released in September 2019.
The NDMA has also taken some other measures including rescheduling of working hours for outdoor workers, creation of drinking water kiosks, supply of water through tankers, erection of special shelter homes, increase in health facilities, stocking of ORS packets at health centres and the nearest anganwadi centres, placement of cooling systems, and construction of gaushalas with fodder banks, etc.
The government claims that deaths due to heat waves dropped from 2,040 in 2015 to just 4 in 2020 because of these aggressive measures taken to deal with heatwaves both by the Centre and states.
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