In 2019, extreme heat resulted in the deaths of over 356,000 people, a statistic that is forecasted to rise, according to recent studies. This revelation underscores the effect of global warming and highlights the increasing frequency of heat waves attributable to climate change.
Understanding Heat Waves
A heat wave is characterized by abnormally high air temperatures which pose a danger to the human body upon exposure. In India, heat waves tend to occur from March till June, occasionally extending till July. These periods of intense heat mainly affect the North-Western and South Central regions. The India Meteorological Department denotes a heat wave when temperatures hit at least 40°C in plains and at least 30°C in hilly regions. This indicates an increase of approximately 5°C-6°C beyond the standard temperature.
Consequences of Heat Waves
Heat waves present multiple risks. The swelteringly high temperatures or humid conditions contribute to an increased risk of heat strokes and heat exhaustion, particularly among older individuals and those with chronic illnesses like heart disease, respiratory disease, and diabetes.
Impact on Health and Economy
Extreme heat gives rise to larger healthcare expenditures due to increased hospitalizations, emergency room visits, deaths from cardio-respiratory diseases and other conditions, mental health problems, adverse pregnancy and birth outcomes, and more.
Effects on Work Productivity and Environment
Work productivity also suffers due to extreme heat, especially among the billion-plus workers exposed to high heat regularly, who often report decreased output due to heat stress. Furthermore, heat waves have been linked to wildfires that destroy substantial land areas annually and impede cloud formation, resulting in high solar radiation levels reaching the ground.
Effects on Agriculture and Energy
The trapped heat can damage crops, parch vegetation, and provoke droughts. Energy demands, particularly for electricity, also escalate, driving up rates.
Challenges in Power Supply
Heat waves represent disasters with a high mortality rate often related to the resilience of the electrical grid, which can fail if the demand for electricity due to air conditioning usage surpasses supply. This leads to a dual risk of infrastructure failure and health impacts.
Recommended Mitigation Measures
Implementing effective environmentally sustainable cooling measures can lessen the severe health impacts of heat. Options include intensifying urban green spaces, using wall coatings that reflect heat from buildings, and promoting the wide-scale use of electric fans and other personal cooling techniques.
Need for Climate Change Action
Climate change mitigation efforts are crucial in reducing carbon emissions, thereby curbing the planet’s warming. The identification and implementation of timely and effective prevention and response methods, especially in low-resource settings, also play a critical role.
Current Initiatives
Various global forums like the World Health Organization, World Economic Forum, the First Global Forum on Heat and Health, and the Global Forum for Environment-OECD are focusing on heat waves by investing in research related to health risks of extreme heat, climate information, guidelines for surviving heat waves, and partnerships for capacity building and improved communication. In India, while the National Disaster Management Authority (NDMA) has issued guidelines to handle heatwaves, heatwaves are not recognized as a disaster under its Disaster Management Act (2005).
Future Outlook
As per the Paris Agreement, limiting global warming to 1.5°C is paramount to prevent significant heat-related mortality in the future. The urgent need to reduce the health impacts of extreme heat involves immediate infrastructure, urban environment, and behavioural changes to forestall heat-related deaths.
