Health impacts of climate change already being felt today

Impacts felt worldwide but will fall most heavily on tropical and sub-tropical regions
Lancet Countdown Infographic

Climate change is already having an impact on health, impacting on labour productivity, the spread of infectious disease and exposure to air pollution and heatwaves, and affecting countries worldwide, according to the first report of The Lancet Countdown on Health and Climate Change.

Report author institutions include the London School of Hygiene & Tropical Medicine, World Bank, World Health Organization (WHO), University College London and Tsinghua University, among others.

By combining multiple data sources, undertaking new analysis and devising new indicators, the report tracks progress in five areas: climate change impacts, exposures and vulnerabilities; adaptation planning and resilience for health; mitigation actions and health co-benefits; economics and finance; and political and public engagement.

The authors report a number of key findings, including:

  • Between 2000-2016, there has been a 46% increase in the number of weather-related disasters, and 125 million adults aged over 65 were exposed to heatwaves
  • Increasing temperatures have led to around 5.3% loss in labour productivity, and economic losses linked to climate-related extreme weather events were estimated at US$129 billion in 2016
  • Vectoral capacity of just one type of dengue-carrying mosquito has increased by 9.4% since 1950 as a result of rising temperatures
  • Global exposure to dangerous levels of air pollution has increased by 11.2% since 1990, with 71% of 2971 cities exceeding recommended levels of PM2.5
  • Increase in electric cars, generation of renewable energy, and health adaptation spending show that momentum is building, but further progress is urgently needed

While there is some evidence of early adaptation and mitigation strategies being implemented in some areas, the authors warn that further progress is urgently needed.

Sir Andy Haines, Professor of Public Health and Primary Care at the London School of Hygiene & Tropical Medicine said: “The Lancet Countdown report shows that growing numbers of people are being exposed to heatwaves and increasing heat stress sufficient to reduce their ability to work as a result of climate change. The health effects of climate change will fall most heavily on tropical and sub-tropical regions but the impacts will be felt worldwide.

“There are positive trends in moving towards a ’low carbon’ economy, for example reductions in coal combustion and growth in the proportion of electricity from clean renewable sources, but greater efforts to decarbonise the world economy are needed  in order to avoid temperature rises greater than two degrees C above the pre-industrial level.”

Some evidence suggests a decline in the use of private motorised vehicles in cities in the USA and Australia, but there has been little improvement for cities in emerging economies. While transport is still heavily dominated by gasoline and diesel, non-conventional fuels (eg biofuels, and natural gas) and electric vehicles are gaining traction, particularly in Europe and the USA. However, these figures remain modest when comparing the overall sales of electric cars per year. Electric vehicles are expected to reach cost-parity with traditional cars by 2018.

In 2015, more energy from renewable sources (solar, wind, hydroelectric) was added to the global energy mix, compared to fossil fuels. However, to remain on the pathway to reaching the Paris Agreement by 2050, this needs to increase by 2.5 times the current levels.

 Global exposure to air pollution (fine particulate matter PM2.5) has increased by 11.2% since 1990, and about 71% of 2971 cities monitored by WHO exceed the recommended levels of PM2.5. The report concludes that momentum is building across a number of sectors, but that further progress is urgently needed.


Nick Watts et al. The Lancet Countdown on health and climate change: from 25 years of inaction to a global transformation for public health. The Lancet. DOI:

Fee discounts

Our postgraduate taught courses provide health practitioners, clinicians, policy-makers, scientists and recent graduates with a world-class qualification in public and global health.

If you are coming to LSHTM to study a distance learning programme (PG Cert, PG Dip, MSc or individual modules) starting in 2024, you may be eligible for a 5% discount on your tuition fees.

These fee reduction schemes are available for a limited time only.