Tackling climate change could be the greatest global health opportunity of the 21st century

This briefing by the Global Climate and Health Alliance argues that climate change and biodiversity loss are the primary global health threats of the 21st century, but that integrating health into climate policy presents a significant opportunity to reduce emissions and improve public health. It details the direct and indirect health risks of warming—including heat-related mortality, air pollution, infectious disease spread, and food system collapse—while highlighting that the health co-benefits of decarbonisation and meeting Paris Agreement goals can substantially offset the economic costs of climate action.

• Climate change and biodiversity collapse are identified as the most significant global health threats of the 21st century. Direct impacts are projected to cause approximately 250,000 additional deaths annually between 2030 and 2050, with associated health costs estimated at USD 2-4 billion per year by 2030. Without mitigation and adaptation, these deaths could rise to 24 million per year. Additionally, fossil fuel emissions contribute to seven million annual deaths from air pollution, and by 2070, between two and three-and-a-half billion people may live in areas rendered unlivable by heat.
• Extreme heat is increasing in frequency and intensity, disproportionately affecting vulnerable groups such as children, the elderly, and low-income communities. In 2021, adults over 65 and children under one were exposed to 3.7 billion more heatwave days than the 1986-2005 average, and elderly heat-related deaths rose by 68% over the last 20 years. Heat stress also impacts labor productivity; in 2021, it caused earnings losses equivalent to 5.6% of GDP in tracked lower-middle-income countries, with 87% of losses in low human development index countries occurring in agriculture. By 2050, 1.5°C warming could expose 350 million more people in megacities like Shanghai and Lagos to heat stress, while 2°C warming could affect one billion people.
• Climate change exacerbates air pollution, which is the fourth leading cause of death globally, killing nearly seven million people annually. In 2019, 99% of the global population lived in areas failing to meet WHO air quality guidelines. This burden is unequal; 89% of ambient air pollution deaths occur in low- and middle-income countries. In the US, 72% of African Americans live in areas violating federal air pollution standards, and Hispanic people are exposed to 63% more air pollution than White people. Warming to 1.5°C could increase ozone-related deaths from 382,000 in 2000 to over 1.9 million by 2100.
• Warming temperatures are expanding the range and suitability for infectious diseases. Between 2015-2019, climate suitability for malaria transmission increased by 39% in Africa and 150% in the Western Pacific compared to the 1950s. Global suitability for dengue fever increased by 11.5%-12% from 1951-60 to 2012-18. Under high emission scenarios, an additional 4.7 billion people could be at risk of exposure to malaria and dengue by 2080. Furthermore, the risk of a pandemic similar to COVID-19 could triple in coming decades due to climate-driven movement between people, wildlife, and vectors.
• Climate change threatens global food security by reducing crop yields and nutritional value. Global agricultural productivity has decreased by 21% since 1961, and major crop yield potential declined by 1.8%-6% between 1981-2010 and 2020. By 2050, 80 million more people could face hunger, particularly in sub-Saharan Africa. In a 2°C scenario, 20-40 million more people would be undernourished compared to a 1.5°C scenario. Additionally, a projected sea level rise of one metre by 2100 could displace up to 565 million people.
• Implementing climate mitigation and adaptation policies offers substantial health and economic co-benefits that can offset the costs of action. Limiting temperature rise to 1.5°C could prevent approximately 150 million premature deaths over the 21st century. While global climate action may cost USD 25 trillion, the resulting savings are estimated to be five to six times larger, with a potential net economic saving of USD 145 trillion if warming is kept below 1.5°C. Specific net benefits for pursuing the 1.5°C target are estimated at up to USD 8.4 trillion for India and USD 2.3 trillion for China.

APA

Global Climate and Health Alliance (2023). Tackling climate change could be the greatest global health opportunity of the 21st century. https://climateandhealthalliance.org/wp-content/uploads/2023/05/GCHA-ClimateHealth-Briefing-May-2023.pdf

Chicago

Global Climate and Health Alliance. Tackling climate change could be the greatest global health opportunity of the 21st century. 2023. https://climateandhealthalliance.org/wp-content/uploads/2023/05/GCHA-ClimateHealth-Briefing-May-2023.pdf.

Wikipedia

{{cite report |author=Global Climate and Health Alliance |title=Tackling climate change could be the greatest global health opportunity of the 21st century |date=May 2023 |url=https://climateandhealthalliance.org/wp-content/uploads/2023/05/GCHA-ClimateHealth-Briefing-May-2023.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{globalclimateandhealthalliance2023tackling, author = {{Global Climate and Health Alliance}}, title = {{Tackling climate change could be the greatest global health opportunity of the 21st century}}, institution = {Global Climate and Health Alliance}, year = {2023}, month = may, url = {https://climateandhealthalliance.org/wp-content/uploads/2023/05/GCHA-ClimateHealth-Briefing-May-2023.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }