Climate change poses serious threats to human health in numerous ways, amplifying existing threats while creating new ones and impacting various communities in varying ways.
Cities, in particular, are especially prone to multiple hazards – urban flooding, extreme heatwaves and air pollution being some examples – that pose risks to health, with geographic displacement being associated with psychological distress and damages to interpersonal relationships.
Rising greenhouse gas levels increase the chances of extreme weather events like heat waves, wildfires and storms occurring, increasing their likelihood as well as their likelihood of having adverse health consequences.
Heat waves, which involve periods of exceptionally high temperatures, have become more prevalent globally in recent years. According to one study, human-caused climate change makes such heatwaves more likely and severe than they otherwise would be.
Studies examining how humans contribute to extreme weather events are growing increasingly common, including their health impacts, known as impact attribution. One such impact attribution study found that humans were responsible for 506 of 735 deaths associated with 2003 European heatwave. Impact attribution could help health systems prepare and respond appropriately when extreme weather occurs.
Water quality and availability is a central pillar of human health. People require clean, safe drinking, cooking and sanitation water as well as reliable sources to sustain livelihoods, agriculture and economic development.
Many parts of the world lack access to sustainable and affordable supplies of water, compounded by climate change impacts like rising temperatures, degraded air quality and extreme weather events like heat waves.
Water scarcity causes numerous health risks, from diarrheal diseases caused by polluted or contaminated water; to musculoskeletal injuries caused by carrying heavy loads; stress, malnutrition and even death when food access becomes limited – especially among vulnerable groups such as poor people, communities of color, those with limited English proficiency and immigrants.
Air pollution comes in various forms; from manufacturing and driving vehicles, burning coal or fuel oils for home heating purposes and other human-caused activities to burning fossil fuels to create energy for lighting homes, there is a myriad of contaminants found in our atmosphere – some caused by us while other come naturally through volcanoes or forest fires releasing dust or ash into the air we breathe.
The CDC is leading efforts to anticipate climate-change-related health threats and ensure systems are in place to detect and respond to them. Our focus is ensuring climate-sensitive risks are tackled with an emphasis on health equity and vulnerable populations – as these groups often face increased heat exposure, flooding and poor air quality as a result of climate change.
Many people depend on nutritious food for survival. Climate change poses an existential threat to these supplies, increasing prices or leading to crop failure, making healthy meals harder to afford than ever.
Global temperatures have steadily increased over the past century, which can largely be attributed to human emissions of heat-trapping gases. Under the Paris Agreement, this warming should be limited to no more than 1.5 degrees Celsius.
Taxes and subsidies on foods with high carbon contents or poor nutrition could help to decrease health care spending and improve population health by shifting purchasing and consumption patterns. But to model this successfully requires understanding how price changes impact diets, disease incidence rates and healthy life years gained due to these patterns, as well as how industry could adapt products so that taxes are avoided.
Climate-change-related health risks have been found to be associated with economic factors, including an inaccessibility to quality healthcare services and insurance that could assist individuals cope with weather-related losses. Climate-related health risks also present vulnerable populations with physiological sensitivities that place them at increased risk, and which increase likelihood of exposure with low adaptive capacity.
Heat-related illnesses, respiratory and cardiovascular diseases, and gastrointestinal conditions become increasingly prevalent as temperatures heat up. Air pollution caused by burning fossil fuels and wildfires worsens; leading to asthma attacks, COPD exacerbations episodes, heart attacks and strokes as a result.
Health systems’ ability to deliver care can also be negatively impacted. Weather-related disasters disrupt supply chains and may leave hospitals short on essential medicines and devices – this can be especially challenging for marginalized communities. Therefore, staff at health systems must be properly trained in recognizing climate health threats and responding appropriately.