The escalating health and economic costs of extreme heat

As temperatures rise each year, the hidden costs of extreme heat impact communities, placing a strain on health systems and economies alike. Since the pre-industrial era, global temperatures have increased by 1.2 degrees Celsius, and with the 15 hottest years on record over the past two decades, extreme heat poses a challenge to us today. According to recent data, extreme heat events have tripled globally since the 1980s, with 2023 setting new records across continents, from North America to Asia, straining communities and health systems.

By mid-2024, India is facing unprecedented heat waves, partly made worse by climate change. In late May, temperatures in Delhi soared to nearly 50ºC, setting a new record in the city and affecting millions of people. Extreme heat is quietly changing the agricultural landscape, accelerating soil erosion, exacerbating draught, and forcing farmers to think about how and what they grow.

Threats posed by extreme heat

Extreme heat impacts everything from our health to the national economy. There is always a risk of health complications during hot summer days, but climate change is causing prolonged periods of extreme heat on the rise. Extreme heat can worsen drought conditions, and the combination of hot, dry weather can create ideal conditions for wildfires. Urban structures like buildings, roads, and sidewalks absorb and trap heat, leading to city temperatures that are 1 to 7 degrees Fahrenheit warmer than nearby rural areas. Rising temperatures across the country are posing a threat to people, ecosystems, and the economy.

Human health

In hotter weather, people face increased risks of dehydration, heat stress, physical injury, and worsening health conditions. Staying too long in extreme heat or sunlight can lead to lasting health issues like kidney problems, heart conditions, increased risk of miscarriage, nervous system damage, or even death. More than 61,000 people died from heat waves across Europe in 2022. A year later, the heat waves are estimated to have caused more than 70,000 deaths.

Heat stress in humans occurs when the body is unable to cool itself through sweating, but when humidity is high, sweat will not evaporate quickly enough, potentially leading to heat stroke. High humidity and elevated night temperatures are likely to be major factors in heat-related illness and mortality. Hot, sunny days can lead to increased levels of ground-level ozone, a dangerous pollutant and main ingredient in smog. This pollutant can irritate the respiratory system, posing serious risks for people with asthma and other lung conditions.

Agriculture

High temperature can be damaging to agriculture. Crop yields are expected to decline as heat stress affects plant growth and reduces water availability. The National Oceanic and Atmospheric Administration (NOAA) predicts that as temperatures rise and rainfall patterns shift, the harvests of important crops like wheat and corn could drop by as much as 30% in the next few decades. From 2014 to 2023, approximately 42.7% of India’s land area has been projected to experience extreme drought conditions for at least one month each year, a rate that has doubled since the 1950s. Extreme heat puts the food supply of billions at risk by interfering with crop growth, harming animals raised for food, and making fishing harder to sustain.

Economic Consequences of Heat Stress

As heat stress intensifies, its economic impact is becoming impossible to ignore. From reduced productivity in labour-intensive industries to increased health care costs, the financial toll of extreme heat is growing rapidly. According to the recent report from the Lancet Countdown on health and climate change for 2024, the situation is serious, with a 50% rise in the number of potential work hours lost due to extreme heat since the 1990s.

This has resulted in economic losses amounting to $141 billion in 2023, with the agricultural sector alone facing a loss of $71.9 billion due to reduced labour capacity caused by extreme heat conditions. These figures underscore the significant financial impact of climate change on productivity across various industries.

How to build resilience to extreme heat?

The publication “Resilience Strategies for Extreme Heat” outlines various approaches to strengthen our ability to cope with extreme heat. Some of these strategies include:

Governments and organizations need to create heat health plans that include early warning systems, awareness campaigns, and safety strategies for at-risk groups.

Implement green and cool roofs, as well as cool sidewalks, to lessen the urban heat island effect.

Planting trees can create shade and help cool the air by releasing moisture through a process called evapotranspiration.

Focusing on energy efficiency to reduce the demand on the electricity grid, particularly during heat waves.

Investing in heat-resistant crops is important for food security as temperatures rise. By using biotechnology and sustainable farming, we can help farmers thrive and maintain a stable food supply.

By ignoring the heat, countries are also ignoring their long-term development and growth , especially their economic growth. We must take collective action to tackle this crisis, implementing strategies that not only protect vulnerable populations but also promote economic resilience in the face of climate change. By implementing adaptive strategies and investing in sustainable solutions, we can reduce the worst impacts of extreme heat and create a more resilient future for all.