As the United Nations climate change conference, COP26, wraps up Nov. 12, physicians and scientists are sounding the alarm about the costly and deadly effect climate change has on health.
In recent years, many researchers have shed light on how climate change creates myriad subsequent health-related problems, either directly or indirectly. The World Health Organization estimates the direct cost of climate change on health to be between $2 billion and $4 billion a year by the end of the decade, and approximately 250,000 more people will die a year between 2030 and 2050 as a result of climate-related diseases.
While these consequences of climate change are monumental, they aren't usually featured in the forefront of climate conversations. However, the pandemic and the crisis it brought called the attention of governments and corporations to the intersection of climate change and health. Engagement with health and climate reached record-high levels in 2020 in media, science, government and the corporate sector, with these industries recognizing the dire reality the world faces without action.
However, individual information-seeking about climate change and health decreased by 15 percent in 2020, according to The Lancet's "Countdown on Health and Climate Change." To clarify the situation, here is a breakdown of the ways climate change affects health outcomes.
Social determinants of health
One way climate change affects health is through social determinants of health. These represent the conditions in which people live, work, play and learn and are increasingly recognized as widely contributing to general health. They include factors like economic stability, community, safety, education access and the built environment. Recent studies suggest social determinants of health account for 30 to 55 percent of health outcomes, making them critical to improve, according to the World Health Organization. Climate change threatens to disrupt social determinants of health, worsening them for all. Extreme weather events like tropical storms, floods and droughts create unsafe environments in which people's regular activities like school and work are disrupted. They also contribute to dangerous environments that can expose people to unclean water, lack of sanitary facilities and malnutrition. This can cause severe distress, affecting mental health and community well-being.
Malnutrition
Higher-than-average temperatures during the growing season can reduce crop yield, with maize yield potential falling by 6 percent and soybean by 5.4 percent in 2020. When paired with extreme weather and soil depletion, malnutrition threatens to affect millions of people worldwide. This issue disproportionately affects rural women who are already food insecure. Destruction of ecosystems that humans are reliant on for food, like marine habitats, will also continue to affect nutrition levels in the affected communities.
Pandemics and viruses
The coronavirus pandemic has alerted people to the dangers of more pandemics in the future. Scientists have discovered a link between infectious diseases and environmental fragmentation, with land-clearing and habitat loss increasing the possibility for spillover events in which animal diseases make the jump to humans. Climate change also increases the incidence of vector-borne diseases like Lyme disease and West Nile virus. Warmer average temperatures extend the length of time that creates hospitable conditions for disease-carrying bugs.
Direct warming
Heat exposure has the potential to affect health in a big way. In 2021, as heat waves made possible by climate change scorched the Northeast U.S., it's estimated that 600 more people died than what would have been typical, according to The New York Times. The increased likelihood of wildfires also poses health risks, the Environmental Protection Agency states, with eye and respiratory tract irritation and infection common from smoke exposure. Obviously, severe cases of wildfire exposure can result in death. Other types of air pollution through burning of fossil fuels have been linked directly to worse health outcomes, including respiratory diseases, cancer and cardiovascular disease. Over 90 percent of people are exposed to unhealthy levels of air pollution, according to WHO.
Climate change continues to be the biggest pressing issue of our time, and evidence clearly shows that it is firmly intertwined with health outcomes. The editors of over 230 top medical journals have already declared climate change as the No. 1 health threat.
Maria Neira, MD, WHO director of environment, climate change and health, put the issue succinctly, saying, "It has never been clearer that the climate crisis is one of the most urgent health emergencies we all face."