Climate change is emerging as one of the world’s biggest public health and economic threats, with an estimated 710,000 heat-related deaths globally in 2023 and productivity losses reaching $1.07 trillion in 2025, according to the 2026 Lancet Countdown report.
The report, prepared in collaboration with the World Health Organization (WHO), reveals that more than 70 percent of heat-related deaths in 2023 were attributable to human-caused climate change. Rising temperatures, prolonged droughts, infectious diseases and worsening environmental conditions are increasing health risks across developed and developing economies.
The findings released on October 28 highlight the growing economic consequences of climate inaction, even as global clean energy investment reaches record levels and renewable energy employment continues to expand.
Extreme Heat Causes 710,000 Deaths, Productivity Losses Reach $1.07 Trillion
The 2026 Lancet Countdown report estimates that heat exposure contributed to 710,000 deaths worldwide in 2023, with human-induced climate change responsible for more than seven in ten fatalities.
Heat-related mortality increased by nearly 36 percent in the period following the 2015 Paris Agreement compared with the preceding decade.
The economic impact is equally significant. Extreme heat caused the loss of 573 billion potential working hours globally in 2025, translating into an estimated $1.07 trillion in lost economic productivity.
Workers in agriculture, construction, manufacturing and other outdoor industries face particularly high exposure to extreme temperatures, creating additional challenges for businesses, employers and governments.
Higher temperatures also increase electricity demand for cooling, placing additional pressure on power grids and energy infrastructure.
Climate Change Accelerates Drought and Infectious Disease Risks
The report identifies worsening drought conditions as another major consequence of global warming.
In 2025, approximately 51.8 percent of the world’s land area experienced extreme drought for at least one month.
The global area affected by extreme drought has been expanding at a rate more than 700 percent faster than during 2006–2015, highlighting the increasing pressure on water resources, agriculture and food security.
Climate change is also creating more favorable conditions for the transmission of infectious diseases.
The climatic suitability for dengue transmission increased by 24 percent for Aedes albopictus mosquitoes and seven percent for Aedes aegypti mosquitoes when comparing 2016–2025 with 1981–1990.
These changes could increase the geographic reach and seasonal duration of dengue transmission, creating additional challenges for public health systems.
Clean Energy Investment Reaches Record $2.1 Trillion
Despite worsening climate-related health risks, the report identifies encouraging progress in clean energy investment and employment.
Global investment in clean energy reached a record $2.1 trillion in 2025, reflecting growing financial commitments to renewable electricity, electrification and low-carbon technologies.
Clean energy employment increased by 2.3 percent in 2024, with the sector employing almost twice as many workers as direct fossil fuel industries.
The expansion of renewable energy and cleaner technologies is also delivering measurable health benefits.
In 70 countries where fossil fuel-related air pollution has declined, cleaner air is estimated to be preventing approximately 323,000 premature deaths annually.
These findings demonstrate that investments in clean energy infrastructure can generate benefits beyond reducing greenhouse gas emissions, including improved public health, lower pollution-related healthcare costs and employment growth.
Oil and Gas Companies Plan Fossil Fuel Production Beyond Climate Targets
The report raises concerns about continued fossil fuel expansion despite growing evidence of climate-related health damage.
The world’s 100 largest oil and gas companies are planning production levels for 2040 that are 150 percent higher than those compatible with limiting global warming to 1.5°C.
This production gap has widened from 138 percent in the previous year’s assessment.
The findings suggest that continued investment in fossil fuel extraction could undermine progress toward international climate targets and increase future health risks.
Researchers warn that delaying the transition toward cleaner energy systems could result in higher mortality, worsening air pollution and greater economic disruption.
Climate Health Laws Increase 50-Fold, but Developing Countries Lag
Governments are increasingly introducing policies addressing the health consequences of climate change.
The number of national laws covering climate change and health has increased approximately 50-fold since 2000, with most legislation introduced after 2016.
However, significant differences remain between developed and developing countries.
Wealthy countries accounted for 55 percent of climate-health laws in 2025, while developing countries accounted for only two percent.
The imbalance highlights disparities in institutional capacity, healthcare infrastructure and access to climate adaptation financing.
Approximately one in four countries now has a national plan to adapt healthcare services to climate change, compared with just 14 WHO Member States in 2015.
Another 47 countries have completed climate-related health vulnerability assessments to support adaptation planning.
WHO Expands Climate Health Monitoring and Early Warning Systems
The World Health Organization is strengthening its response to climate-related health risks through surveillance systems, early warnings, adaptation planning and emergency preparedness.
The agency is also monitoring the health consequences of the ongoing El Niño event, particularly in countries vulnerable to extreme temperatures, flooding and infectious disease outbreaks.
Through the Alliance for Transformative Action on Climate and Health (ATACH), WHO supports countries in developing climate-resilient, low-carbon healthcare systems.
The 2026 Lancet Countdown report, led by University College London and involving international research institutions, examines 54 indicators connecting climate change with human health.
Its findings come as the World Meteorological Organization reports record atmospheric concentrations of carbon dioxide and other major greenhouse gases in 2025.
Ahead of the COP31 climate conference in Antalya, Türkiye, researchers are calling for faster emissions reductions, greater climate adaptation financing and stronger investments in healthcare resilience.
The report’s central finding is that climate change is no longer only a long-term environmental concern. With 710,000 heat-related deaths, $1.07 trillion in lost productivity and more than half of global land experiencing extreme drought during 2025, its consequences are already affecting public health, economic growth and workforce productivity worldwide.
BABURAJAN KIZHAKEDATH
