We’ve covered the impact of climate change on our environments and livelihoods, but it is no secret that the state of our climate has great consequences for human health and wellbeing.
In fact, climate change presents a fundamental threat to human health: Weather and climate hazards affect health both directly and indirectly, increasing the risk of deaths, noncommunicable diseases, the emergence and spread of infectious diseases, and health emergencies.
Key Risk Factors of Climate Change on Human Health
Climate-related hazards like extreme weather events (hurricanes), extreme heat, sea level rise, air pollution, water scarcity, and reduced food production can all have direct effects on our physical health and that of our communities. They also impact our health workforce, our infrastructure, our utility systems (water, electricity, internet), our food systems, and of course, our health systems. And since climate change doesn’t impact us all equally, it can make the situation worse for people who were already underserved by these systems in the first place.
This diagram from the Caribbean Public Health Agency (CARPHA) depicts the ways that different climate impacts affect human health.
Heat-related Illness and Death
Heat waves are increasing in frequency, intensity, and duration, posing the threat of increased heat-related illness and death. Research shows that almost 40% of heat-related deaths today are caused by human-induced climate change.
Vulnerability to heat is understood as a function of exposure to heat and the sensitivity of people. Several variables contribute to heat vulnerability with higher rates in those living alone, people with disabilities, the elderly, people with pre-existing health conditions (e.g. cardiovascular), and people without health insurance. At the same time, the sensitivity of people to heat depends on a range of individual factors, which may influence their ability to adapt and to cope with extreme temperatures.
Urban areas are more prone to the urban heat island effect, where the temperature actually becomes higher in cities compared to surrounding areas. Thus the hottest and most vulnerable areas correspond with highly built-up areas, and the coolest correspond with vegetated landscapes and bodies of water (e.g. rivers, botanical gardens, parks and fields). Green infrastructure, including building more tree cover along roadways, are key to regulating extreme heat.
Injury and Mortality from Extreme Weather Events
Extreme events like hurricanes and cyclones are the most immediate ways that people in the Caribbean experience climate impacts. Besides the direct impact of hurricanes on our physical and mental health, short- and long-term effects also need to be monitored. Extreme weather events can cause major disruptions in essential services (e.g. potable water and electric power, telecommunications, transportation) and environmental health issues (e.g. water sanitation, contaminant exposure, vector-borne diseases, food hygiene, carbon monoxide poisoning, and exposure to mould).
More frequent and intense hurricanes, combined with poor infrastructure and social determinants of health, will most likely generate interruption in medical care, a particular concern for sensitive groups, vulnerable communities, and disadvantaged communities. In vulnerable regions, the death rate from extreme weather events in the last decade was 15 times higher than in less vulnerable ones.
Vector-borne Diseases
In the Caribbean, vector-borne diseases like malaria, dengue, encephalitis, chikungunya and others are mostly transmitted by mosquitoes, who act as vectors that cause the spread of disease from insect to human. Researchers suggest that mosquitoes have excellent adaptation skills that will enable them to survive rising temperatures and extreme conditions. In fact, temperature and precipitation changes enhance the spread of vector-borne diseases. Without preventive actions, deaths from such diseases, currently over 700 000 annually worldwide, may rise.
At present, there is no effective vaccine or therapy to counter the symptoms of dengue, chikungunya and zika, all of which are transmitted by mosquitoes. Dengue is among the most common diseases of humans, with more than one-third of the world’s population at risk. Other important factors in human susceptibility to these diseases include immunity and mobility of the population, socio-economic factors (inequality and poverty), public policy, implementation of surveillance systems, dengue control programs, and deficient septic tank conditions.
Respiratory viruses, Allergies and Asthma
Air pollution is of course one of the factors that makes climate change worse, and also has direct impacts on human health, from asthma to allergies. Seasonal Sahara dust outbreaks have increased in concentration in the last few decades and whether they will worsen is yet to be determined as the climate crisis wages on. Microorganisms in airborne particulate matter or dust can also be linked to infectious diseases.
SARS, MERS, and influenza transmission are often associated with seasonal variability and climate trends, but not all seasonal respiratory viruses exhibit the same patterns. It is yet to be confirmed whether COVID-19 will follow similar patterns.
CARPHA Climate Roadmap Strategic Imperatives
Climate Action is a key mitigation measure to lessen the health impacts on humans.
In response to the risks highlighted above, CARPHA has developed the Climate Roadmap Strategic Imperatives, that call for:
- Raised awareness of Climate Change and health through information dissemination, communication and education
- Strengthened community-and technology-enabled resilience to address the cumulative threat of climate change and severe weather events
- Bolstered and integrated multi sectoral data and evidence for decision making
- Enhanced regional sustainability and resilience of health facilities
- Maximized benefits of the built environment and Climate Change resilience
Author: Alicia Richins
Sustainable Impact Strategist | SDG Champion | Climate Justice Advocate | Climate Futures Writer
