Key scientific concerns about climate change are based on extensive evidence from observations, climate models, and multiple scientific disciplines studying Earth’s climate system. This is the seventh article on the series of eight concerns.
A. HUMAN HEALTH RISKS RELATED TO CLIMATE CHANGE:
Climate change is increasingly recognized as one of the greatest threats to human health in the 21st century. Rising temperatures, changing weather patterns, and more frequent extreme weather events affect both physical and mental health. According to the World Health Organization (WHO), climate change threatens the fundamental requirements for good health: clean air, safe drinking water, nutritious food, and secure shelter.
A.1 OVERVIEW OF HEALTH RISKS:
Source: Riskonnect
Climate change affects human health in numerous ways, leading to both direct and indirect health impacts. Some of the key health risks include:
- Extreme Weather Events: Increased frequency and intensity of heatwaves, storms, floods, and wildfires can lead to injuries, deaths, and mental health issues. For instance, heatwaves can double or triple the number of heat-related deaths. It also increases the following incidents:
- Heat Exhaustion and Heat Stroke;
- Dehydration;
- Kidney problems;
- Cardiovascular disease complications; and
- Respiratory distress.
Older adults, young children, outdoor workers, and people with chronic illnesses are particularly vulnerable. The WHO estimates that heat-related mortality has increased substantially in many regions.
- Poor Air Quality: Poor air quality, exacerbated by climate change, can lead to increased rates of respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD). The rise in temperatures can worsen cardiovascular conditions. Climate change also worsens air pollution through:
- Increased formation of ground-level ozone;
- More frequent wildfires; and
- Longer pollen seasons.
- Spread of Infectious Disease: Climate change alters the distribution of disease-carrying vectors like mosquitoes and ticks, leading to the spread of diseases such as:
- Malaria;
- Dengue fever;
- Lyme Disease; and
- West Nile Virus.
Changes in climate can also increase the prevalence of waterborne diseases due to flooding and contamination of water supplies.
- Food Insecurity and Malnutrition: Climate-related droughts, floods, and changing growing conditions can reduce agricultural productivity and food quality. Potential consequences include:
- Undernutrition;
- Micronutrient deficiencies;
- Increased food prices; and
- Greater vulnerability among low-income populations.
Reduced crop yields threaten both food availability and nutritional value.
- Water-Related Diseases: Extreme rainfall and flooding can contaminate drinking water supplies, while droughts reduce access to safe water. Health impacts include increased incidence of:
- Diarrhoeal diseases;
- Cholera;
- Gastrointestinal infections; and
- Dehydration.
Children are particularly susceptible to these illnesses.
- Injuries and Death from Extreme Weather Events: Climate change increases the frequency and severity of:
- Floods;
- Hurricanes;
- Storm surges;
- Wildfires; and
- Droughts.
These disasters can result in:
- Physical injuries;
- Fatalities;
- Population displacement; and
- Disruption of health services and infrastructure.
- Mental Health Impacts: Climate-related events can significantly affect psychological well-being.
Common mental health outcomes include:
- Anxiety and depression;
- Post-traumatic stress disorder (PTSD);
- Grief following loss of homes or livelihoods; and
- “Eco-anxiety” associated with concerns about future environmental changes.
The psychological burden often persists long after disasters have ended.
A.2 VULNERABLE POPULATION:
Although climate change affects everyone, certain groups face higher risks:
- Older adults;
- Infants and children;
- Pregnant women;
- Individuals with chronic illnesses;
- Indigenous communities;
- Low-income populations;
- Outdoor workers; and
- People living in regions with weak health infrastructure.
The WHO notes that vulnerable communities often contribute the least to greenhouse gas emissions yet experience the greatest health impacts.
B. MONETARY IMPACT OF HUMAN HEALTH RISKS:
Human health risks associated with climate change impose a growing financial burden on healthcare systems, economies, and societies worldwide. These costs arise from increased illness, premature deaths, reduced labour productivity, emergency responses, and the need to strengthen health infrastructure.
B.1 DIRECT HEALTHCARE COSTS:
The WHO estimates that climate change will generate direct health-related damages of between US$2 billion and US$4 billion annually by 2030. These costs include treatment and management of climate-sensitive diseases such as:
- Heat-related illnesses;
- Malaria;
- Diarrhoeal diseases;
- Childhood undernutrition; and
- Injuries associated with extreme weather events.
Importantly, these figures exclude broader costs affecting agriculture, water systems, sanitation, and social services.
B.2 MORTALITY AND PODUCTIVITY LOSSES:
WHO projects that between 2030 and 2050, climate change could cause approximately 250,000 additional deaths annually, resulting from:
- 95,000 deaths from childhood undernutrition;
- 60,000 from malaria;
- 48,000 from diarrhoeal disease; and
- 38,000 from heat exposure among older adults.
Beyond the tragic loss of life, these deaths translate into substantial economic losses through:
- Reduced workforce participation;
- Lost productivity;
- Lower household incomes; and
- Increased dependency ratios.
Climate change is expected to cause “Approximately 250,000 additional deaths per year between 2030 and 2050.”
B.3 GLOBAL ECONOMIC LOSSES LINKED TO HEALTH IMPACTS:
A report prepared by the World Economic Forum in collaboration with Oliver Wyman estimated that climate-related health impacts could result in:
- 14.5 million additional deaths by 2050; and
- US$12.5 trillion in cumulative global economic losses.
These losses stem from:
- Reduced labour productivity;
- Increased healthcare expenditures;
- Mental health impacts;
- Disease outbreaks; and
- Population displacement.
The report warns that climate change may cause “$12.5 trillion in economic losses worldwide” by 2050 through its impacts on human health.
B.4 BROADER CLIMATE DAMAGES AFFECTING HEALTH:
Recent research from the Potsdam Institute for Climate Impact Research suggests that overall climate damages—including impacts on health, agriculture, infrastructure, and productivity—could amount to:
- US$38 trillion annually by 2050 which is equivalent to approximately 17 percent of global GDP.
Although health represents only one component of these losses, deteriorating public health significantly amplifies economic damages through:
- Increased healthcare demand;
- Lost working days;
- Reduced cognitive and physical performance; and
- Long-term disability.
C. CONCLUSION:
Human health risks arising from climate change are no longer solely a public health concern; they represent a major economic challenge. Rising temperatures, worsening air quality, expanding infectious diseases, food insecurity, and extreme weather events increase healthcare expenditures while simultaneously reducing economic productivity. Investments in climate mitigation and adaptation can therefore be viewed not only as environmental necessities but also as prudent economic strategies that may prevent trillions of dollars in future losses.
D. FUTURE OUTLOOK:
The WHO estimates that between 2030 and 2050, climate change could cause approximately 250,000 additional deaths annually from undernutrition, malaria, diarrhoea, and heat stress alone. Direct health-related economic damages are projected to reach US$2–4 billion per year by 2030.
Please click the following link to watch a brief video (2:34 Minutes) which was produced by American College f Physicians:
