Climate change is bad for health but climate services save lives

02 November 2023

As the world warms at a faster rate than at any point in recorded history, human health is on the frontline.

Climate change threatens to reverse decades of progress towards better health and well-being, particularly in the most vulnerable communities. Scientific know-how and resources can help redress the balance, but are not sufficiently accessible or utilized, according to a new multi-agency report coordinated by the World Meteorological Organization (WMO).

Key messages
  • Climate change threatens to reverse health gains
  • Extreme heat causes greatest mortality of all extreme weather events/ hazards
  • Climate information and services help manage and predict health risks
  • Case studies showcase success stories around the world

WMO’s annual State of Climate Services report this year focuses on health. It highlights the need for tailored climate information and services to support the health sector in the face of more extreme weather and poor air quality, shifting infectious disease patterns and food and water insecurity.

“Practically the whole planet has experienced heatwaves this year. The onset of El Niño in 2023 will greatly increase the likelihood of breaking temperature records further, triggering more extreme heat in many parts of the world and in the ocean – and making the challenge even greater,” says WMO Secretary-General, Prof. Petteri Taalas.

“It is clear that by channelling investment and boosting collaboration, there is huge potential to go further and faster by enhancing the impact of climate science and services so that health partners get the support they need at a time when unprecedented changes to our climate are having an increasing impact,” says Prof. Taalas.

The report, which includes input from more than 30 collaborating partners, features case studies from around the world showcasing how integrated climate and health action makes a very real difference in people’s daily life. This includes early warning systems for extreme heat, pollen monitoring to help allergy sufferers and satellite surveillance for climate-sensitive diseases.

“The climate crisis is a health crisis, driving more severe and unpredictable weather events, fuelling disease outbreaks, and contributing to higher rates of noncommunicable diseases,” said Dr Tedros Adhanom Ghebreyesus, WHO Director-General. "By working together to make high-quality climate services more accessible to the health sector, we can help to protect the health and well-being of people facing the perils of climate change."

Nearly three quarters of National Meteorological and Hydrological Services (NMHS) provide climate data to the health sector, but the uptake is limited. Less than one quarter of Ministries of Health have a health surveillance system that utilizes meteorological information to monitor climate-sensitive health risks.

A map showing the percentage of the world's population.
Overview of climate services capacities (not sector specific)

Early Warnings for All

The number of medium- or large-scale disaster events is projected to reach 560 a year – or 1.5 each day – by 2030. Countries with limited early warning coverage have disaster mortality that is eight times higher than countries with substantial to comprehensive coverage, according to figures cited in the report.

A special section is devoted to extreme heat, which causes the greatest mortality of all extreme weather. However the impacts are underestimated as heat-related mortality could be 30 times higher than what is currently recorded. Heat warning services are provided to health decision makers in only half of the affected countries, but are expected to rapidly increase by 2027 under the international Early Warnings for All initiative.

Between 2000 and 2019, estimated deaths due to heat were approximately 489,000 per year, with a particularly high burden in Asia (45%) and Europe (36%).  Extreme heat conditions during the summer of 2022, were estimated to have claimed over 60,000 excess deaths in 35 European countries.

Heatwaves also exacerbate air pollution, which is already responsible for an estimated 7 million premature deaths every year and is the fourth biggest killer by health risk factor.

Climate change is exacerbating risks of food insecurity. In 2012-2021, 29% more global land area was affected by extreme drought for at least one month per year than in 1951–1960. The compounding impacts of droughts and heatwave days were associated with 98 million additional people reporting moderate to severe food insecurity in 2020 than annually in 1981–2010, in 103 countries analysed, according to figures cited in the report.

The changing climatic conditions are also enhancing the transmission of many climatically sensitive infectious vector-, food-, and water-borne diseases. For example, dengue is the world’s fastest-spreading vector-borne disease, whilst the length of the malaria transmission season has increased in parts of the world.

Some of the most significant challenges to health are in the nexus of water, food security and nutrition, the nexus of infectious diseases (food-, water-, airborne and vector-borne diseases), and the nexus of extreme weather and air quality, particularly in urban areas, says the report.

Climate change undermines health determinants and increases pressures on health systems threatening to reverse decades of progress to promote human health and well-being, particularly in the most vulnerable communities.

The Intergovernmental Panel on Climate Change (IPCC) concludes, with very high confidence, that future health risks from injury, disease, and death will increase due to more intense and frequent temperature extremes, cyclones, storms, floods, droughts, and wildfires. It is anticipated that over 50% of the excess mortality resulting from climate change by the year 2050 will occur in Africa.

Health protection is a priority in almost all countries and requires high-quality information to better inform decision-making.  Climate information and services are fundamental for better understanding how and when health systems and population health can be impacted by climate extremes and a changing climate, and for managing climate-related risks.

Climate information and services are fundamental for better understanding how and when health systems and population health can be impacted by climate extremes and a changing climate, and for managing risks. Tailored climate products and services can enhance the evidence and information available to health partners to detect, monitor, predict, and manage climate-related health risks.

There is huge potential for enhancing the benefits of climate science and climate services for the health sector and for increasing accessibility, relevance and uptake.  Only 31% of NMHSs provide climate services at a ‘full’ or ‘advanced’ level of capacity. A large range of academic, private sector, and government partners are also working to fill the gap, and this needs to be put on a sustainable and coordinated footing.

Extreme head causes the greatest mortality of all extreme weather slide
Extreme head causes the greatest mortality of all extreme weather

Extreme heat causes the greatest mortality of all extreme weather, yet heat warning services are provided to health decision makers in only half of the affected countries. According to the Lancet Countdown on Health and Climate Change, rising temperatures and the growing over-65 population have triggered an increase in heat-related mortality in this age group of approximately 68% between 2017-2021, compared to 2000-2004.

According to the IPCC, there is “high confidence” that Central and South America, southern Europe, southern and Southeast Asia and Africa will be the most affected by climate change in terms of heat-related mortality by 2100, based on 1.5°C, 2°C and 3°C increases in the global temperature.

The IPCC also notes with “very high confidence” significant impacts of heat are expected from the combination of future urban development and the more frequent occurrence of heatwaves, with more hot days and warm nights adding to heat stress in cities.

Concerns relating to air quality, climate change, and health are interlinked. Climate mitigation action leading to reducing air pollution can save lives. Despite this, only 2% of climate finance commitments made by international development funders in developing and emerging countries is explicitly aimed at tackling air pollution (in 2015-2021), even though it is the most dangerous environmental threat to health.

In 2019, air pollution moved up from the fifth to the fourth place in the scale of leading risk factors for death globally, continuing to exceed the impacts of other widely recognized risk factors for chronic disease like obesity, cardiovascular disease, and malnutrition.

There is insufficient investment to improve the capabilities of the health sector, leaving it ill-prepared to safeguard the most vulnerable. Currently, just 0.2% of total bilateral and multilateral adaptation finance supports projects that identify health as the primary focus, and the investment in the capacity for multisectoral and effective climate science and services is miniscule."

Most hydrometeorological investments are not clearly designed to support health outcomes. This needs to change.

To fully harness the potential of climate services for health, transformational change in institutional development and integration across the health and climate sectors are needed.

In the wake of the global COVID-19 pandemic, all countries have experienced the social and economic losses and damages which can occur when the health of society is compromised. More must be done to prepare the health community for future shocks and pressures they may experience due to climate variability and the damaging effects of climate change.

The governing World Meteorological Congress in 2023 approved a 10-year strategy on Advancing Integrated Climate, Environment, and Health Science and Services (2023–2033) in collaboration with WHO and other health partners to address the challenges.

Climate change impacts are not experienced equally (slide)
Climate change impacts are not experienced equally.

Success stories

Examples of benefits of climate services for health, include:

In Africa, food security and shock response systems support social protection in Mauritania and the Sahel. Humanitarian organizations are improving clean water provision and nutrition through drought anticipation measures in Kenya

In Europe, a mobile app has been developed to provide information on risks of heatwaves and air pollution in urban environments. Real-time observations of aeroallergens are revolutionizing the information available to users of the app – and improving the health of millions of European allergy patients. The Local Climate Adaptation Tool supporting local decision makers in the UK to identify adaptation measures

In the Pacific, enhanced integrated risk monitoring and climate-informed early warning systems have helped people in Fiji better prepare and respond to climatic changes, reducing morbidity and mortality from climate-sensitive diseases. Australia played a leading role in the develop of a Sun-Smart App to protect people against harmful UV levels.

In the Pan-American region, early warning systems for extreme heat and cold in Argentina were pioneered with the health and civil protections sectors.

Climate and Health Bulletins in the Caribbean and Colombia improve the management of environmental health and climate services. There are Smart Health Care facilities (weather-resilient and environmentally friendly) in the Caribbean. The One Health approach helps to integrate weather, water, and climate services in the USA, whilst Canada uses model-based risk assessments of vector-borne disease emergence.

In Southeast Asia, satellites support the integration of climate and environmental information into health surveillance systems for Myanmar, and the development of an integrated early warning system for dengue in Vietnam and measures to enhance the resilience of the most vulnerable settlements in Lao PDR.

Notes to Editors

WMO, through its Global Framework for Climate Services, issues annual reports on the State of Climate Services since 2019 in response to a United Nations request for more information on adaptation needs of countries. The reports helps countries, funding agencies and development partners to identify steps needed to address climate services gaps and needs, inform more effective investments, and enhance adaptation and development outcomes.

A dedicated web-portal,, was launched jointly by WMO and the WHO in 2022 to help improve climate literacy and accelerate access to relevant information for policymakers, practitioners, researchers, media, and students.

The following organizations contributed to this report:

Adaptation Fund
Aerosol and Climate Lab, Lund University
Agence Française de Développement
Barcelona Supercomputing Center
Belmont Forum
Cancer Council of Victoria
Caribbean Institute for Meteorology and Hydrology
Caribbean Public Health Agency
Catalan Institution for Research and Advanced Studies
Climate Policy Initiative
Climate Risk and Early Warning Systems
Direction de la Météorologie Nationale of Niger
EUMETNET AutoPollen Programme and Swiss Federal Office for Meteorology and Climatology - MeteoSwiss
European Centre for Medium-Range Weather Forecasts and the Copernicus Atmospheric Monitoring Service
Exemplars in Global Health
French National Research Agency (ARN)
Getulio Vargas Foundation (FGV)
Global Atmosphere Watch
Global Environment Facility
Graduate Institute of International and Development Studies
Green Climate Fund
Group on Earth Observations
Institut de Recherche pour le Développement (IRD)
Instituto de Hidrología, Meteorología y Estudios Ambientales (Colombia)
Kenya Red Cross Society
Lancet Countdown on Health and Climate Change
Lancet Countdown on Health and Climate Change in Europe
National Observatory of Athens
National Oceanic and Atmospheric Administration
Pan American Health Organization
Red Cross Red Crescent Climate Center
Servicio Meteorológico Nacional of Argentina
SickKids Centre for Global Child Health (Toronto)
The Aga Khan University (Pakistan) 
United Nations Development Programme
University of Cambridge
University of Exeter
University College London United States Global Change Research Program
Wellcome Trust
World Health Organization
World Meteorological Organization

The World Meteorological Organization (WMO) is a specialized agency of the United Nations responsible for promoting international cooperation in atmospheric science and meteorology.

WMO monitors weather, climate, and water resources and provides support to its Members in forecasting and disaster mitigation. The organization is committed to advancing scientific knowledge and improving public safety and well-being through its work.

For further information, please contact:

  • Clare Nullis WMO media officer +41 79 709 13 97
  • WMO Strategic Communication Office Media Contact
Press kit