Climate Change: A Fundamental Threat to Human Health
Overview: Climate change presents a fundamental threat to human health, impacting the physical environment and all aspects of natural and human systems, including social, economic conditions, and health system functioning. It acts as a threat multiplier, potentially reversing decades of health progress by increasing the frequency and intensity of extreme weather events such as storms, heatwaves, floods, droughts, and wildfires. These events directly and indirectly increase the risk of deaths, noncommunicable diseases, the spread of infectious diseases, and health emergencies.
Health Workforce and Infrastructure Impact: Climate change affects health infrastructure and the capacity to provide universal health coverage (UHC). Environmental and social determinants of health, such as clean air, water, soil, food systems, and livelihoods, are degraded by climate shocks and stresses, including changing temperature patterns, droughts, floods, and rising sea levels.
IPCC’s Sixth Assessment Report: The Intergovernmental Panel on Climate Change’s (IPCC) Sixth Assessment Report (AR6) reveals that climate risks are accelerating and becoming more severe. It highlights that 3.6 billion people live in areas highly susceptible to climate change, with low-income countries and small island developing states (SIDS) bearing the harshest health impacts despite minimal contributions to global emissions. Vulnerable regions have seen a death rate from extreme weather events 15 times higher than less vulnerable areas.
Health Impacts of Climate Change:
- Direct Health Impacts: Death and illness from extreme weather events like heatwaves, storms, and floods.
- Indirect Health Impacts: Disruption of food systems, increased zoonoses, and food-, water-, and vector-borne diseases. Mental health issues due to displacement and social disruption.
- Social Determinants: Livelihoods, equality, and access to healthcare and social support are undermined.
Vulnerable Populations: Climate-sensitive health risks disproportionately affect the most vulnerable and disadvantaged, including women, children, ethnic minorities, poor communities, migrants, older populations, and those with underlying health conditions.
Scientific Advances: While it is challenging to estimate the full scale of climate-sensitive health risks, scientific advances allow for better attribution of morbidity and mortality to global warming. WHO data indicates that 2 billion people lack safe drinking water, and 600 million suffer from foodborne illnesses annually. Climate change exacerbates waterborne and foodborne disease risks, hunger, and the spread of vector-borne diseases.
Projected Health Impacts: Recent research attributes 37% of heat-related deaths to human-induced climate change, with a significant increase in heat-related deaths among those over 65. The WHO projects 250,000 additional yearly deaths by the 2030s due to climate change impacts on diseases like malaria and coastal flooding.
Economic and Social Consequences: Climate change threatens to undo 50 years of progress in development, global health, and poverty reduction, exacerbating health inequalities. Health shocks already push around 100 million people into poverty annually, a trend worsened by climate change.
WHO’s Response: WHO’s response centers around three main objectives:
- Leadership and Raising Awareness: Emphasizing the health implications of climate change and centralizing health in climate policies.
- Evidence and Monitoring: Contributing global evidence, assisting nations in assessments, and monitoring progress.
- Capacity Building and Country Support: Supporting ministries of health through collaboration, guidance, training, and project execution.
Global Commitment: To prevent catastrophic health impacts and millions of climate-related deaths, the world must limit the temperature rise to 1.5°C. Every additional tenth of a degree of warming will severely impact people’s lives and health. WHO aims for carbon neutrality by 2030 and leads the Alliance for Transformative Action on Climate and Health (ATACH) to support climate-resilient and low-carbon health systems.
Related Resources:
- News
- Fact sheets
- Feature stories
Source: WHO
