Climate Change and Population Health

By Jasmine Ryu Won Kang

There are few global health crises as consequential and ubiquitous as the one imposed by climate change. Described by the United Nations as the “defining issue of our time,” it’s a term that finds its way into world summits, classrooms, and research facilities alike. The myriad and oft-cited chemical and geophysical changes to the Earth – from rising temperatures to polar ice decline – hold far-reaching implications to human health. Augmented by pre-existing poverty, discrimination, and lack of access to health care, the effects of climate change are particularly pronounced in certain communities that already face a lack of access to healthcare. Climate change, societal factors, and health are, therefore, dynamically intertwined.

Climate change and health

The independent effects of climate change on health are perhaps the most visible. In Canada, this is most apparent in the Far North. One of the most vulnerable regions to climate change, the Arctic is warming at triple the global rate. Rapid thawing of permafrost and ice roads is not only a tangible sign of warming temperatures, but also a significant obstacle in the delivery of food and medical supplies to Arctic communities.

According to the Council of Canadian Academies’ report on Canada’s Top Climate Change Risks, health and human wellness ranks among the top six. Worsening air pollution due to wildfires, intense and prolonged pollen seasons, and record-breaking temperatures contribute to higher incidences of cardiorespiratory illnesses and heat-related deaths. In the summer of 2018, there were more than 90 such deaths in Quebec, and temperatures exceeded 30 degrees for a total of 21 days in Ontario. Meanwhile, in BC air pollution was routinely rated as “high risk” and “very high risk” due to smoke from the nearly 600 wildfires created that summer.

Globally, warmer temperatures are expected to increase the spread of vector-borne diseases through the expansion of geographical range of various parasites. For instance, the

environmental suitability for Plasmodium falciparum, the malaria-causing protozoan parasite,

increased by about 21% from the 1950s to the 2010s. Furthermore, these alterations in the range and seasonality of infectious disease are also predicted to affect the occurrence of food-borne infections, such as salmonellosis, many of which peak in the warmer months.

In the broader context of social determinants

Economic and social conditions are also major factors that can influence or even determine the health-related quality of life of individuals and communities. Early childhood development, food security, living conditions, and social attitudes all play a role in the ability of an individual to access high-quality healthcare. Regardless of his or her biological predisposition, these social determinants may obstruct that individual from attaining the desired level of health. Health inequity is indeed a product of an amalgamation of social challenges, such as poverty, lack of education, and stigma.

One of the most detrimental hurdles in understanding how climate change interacts with such social factors is the lack of data on the impacts of climate change in low-income countries. However, there undoubtedly exists a connection between the lack of economic opportunities in a society and its ability to cope with the adverse effects of climate change. For instance, in a recent study conducted in the central mountainous region of eastern Mexico, it was found that socioeconomic vulnerability is increased in regions where temperature is elevated and precipitation is decreased. In addition, exposure to air pollutants and soil and water contamination is frequently higher in the same communities that also experience reduced access to health insurance and public transportation.

In altering the Earth’s biophysical and ecological systems, we are inadvertently also changing its social landscape. More precisely, existing health inequities in communities are exacerbated by the changing climate, both within Canada and globally. In order to understand the climate crisis, we must look beyond the physical phenomena and question their social impact on the health of populations.