Health Effects of Climate Change

Examining evidence-based findings on climate change and projecting future natural hazards will help prepare mitigation and adaptation strategies and reduce potential consequent adverse health outcomes. Predicting changes in the Earth’s climate system through anticipating the effects of future natural hazards is critical not only for disaster planning and emergency preparedness, but to consider long-term priorities that generate resilience in various aspects of society such as within communities, ecosystems, and economies.

Rural communities especially those that are socioeconomically disadvantaged will experience disproportionate health impacts due to climate change. These will include:

Emerging and Remerging Diseases: COVID-19

The emergence and spread of the coronavirus disease (COVID-19) is an indirect result of ecosystem disruption, as many of the effects of climate change increase the risk of disease outbreaks and pandemics. As climate change alters our environments’ temperature, moisture levels, and precipitation patterns, the natural niches of many species will change forcing many to migrate to new habitats, contacting other species and increasing the possibility of the spread and mutation of zoonotic and vector-borne diseases (Figure 5).⁴⁰ Examples of vector-borne diseases that are increasingly impacting Canada include West Nile virus and Lyme disease, both of which can have long-lasting negative effects on patients.⁴¹

The COVID-19 pandemic continues to pose a threat to rural communities due to an aging demographic, limited resources, and more significant barriers to accessing health services than may be experienced in urban communities. As our climate continues to change, there is an increasing likelihood that the COVID-19 pandemic is representative of a new normal as novel pathogens emerge from melting glaciers and permafrost⁴² and interactions with wild animals increase as humans infringe on their natural habitats.⁴⁰ The ongoing challenges of the COVID-19 pandemic have highlighted a need to better understand how rural communities are impacted by and are adapting to ecosystem threats.

Mental Health in Rural Areas

Mental health has been found to play a crucial role in overall human health. Mental health can be impacted by many factors including physical health, environment, genetics, and socioeconomic conditions. Climate change and its devastating effects can significantly impact mental health not only by threatening environmental conditions, such as air quality, but also by threatening livelihoods and thus, socioeconomic conditions. For example, a study on mental health and climate change found that exposure to a natural disaster, such as a flood, is correlated with higher levels of anxiety among affected populations.⁴³ The same study found that, “about 24% of those who applied for disaster assistance after a wildfire in California showed symptoms of PTSD at a three-month follow-up”.⁴³ In Kelowna, after the devastating 2003 fire, for instance, a medical officer identified numerous patients exhibiting PTSD as well as mental and physical trauma.⁴⁴ Climate-related hazards and disasters can also trigger and exacerbate existing mental health illnesses such as anxiety, depression, PTSD, and acute stress disorder. Because rural communities are often more dependent than urban areas on the environment and natural resources as a source of income, the impacts of climate change can contribute to more considerable socioeconomic and mental health challenges amongst these populations. ⁴³

There are some global initiatives addressing the impacts of changing and uncertain environmental conditions in rural areas on mental health and well-being. For example, The Rural Adversity Mental Health Program of Australia has implemented local initiatives to support mental health during extreme drought and forest fires. ‘The One Book, One Community’ initiative is a book club for various communities to gather and share each other’s reflections. The meetings are also provided virtually to ensure accessibility and inclusivity. This initiative strives to foster conversations and social connection amongst rural communities.⁴⁵ Additionally, the Centre for Rural and Remote Mental Health (CRRMH) and the Rural Adversity Mental Health Program launched ‘You Got This Mate’, a website providing mental health resources specifically for rural men in Australia.⁴⁶ Although literature investigating how natural disasters affect mental health is very limited, the existing research suggests that solutions must be tailored for susceptible and affected communities, such as rural communities, in order to help them to build resilience into the future.⁴⁶

Respiratory Illnesses

The increase in air pollutants such as CO2 and fine particulate matter are progressively decreasing global air quality. With increases in aeroallergens and infectious aerosols, respiratory health has become a major health concern for all ages. Human activity is the most significant source of  greenhouse gases emissions and particulate matter contributing to deteriorating air quality. These activities include the combustion of biofuels, diesel exhaust, and black carbon. Many of these have also been identified as potent carcinogens. ^{47, 48}

In addition to pollutants emitted through human activities, increased temperature accelerates and prolongs the pollen season, and thus allergy season, as well as increases the dryness of forests, increasing the frequency and severity of forest fires, thus increasing the risk of smoke-related respiratory infections and diseases. These respiratory distress exacerbators have resulted in a higher incidence of respiratory conditions such as asthma, chronic obstructive pulmonary disease (COPD), respiratory tract damage, and inflammation.⁴⁹

Food and Water Quality and Safety

Health Impacts of Changes to Food and Water Quality and Access

More so than urban residents, rural and Indigenous communities rely on their natural environment for food and water. These communities may experience increased food insecurity, resulting in higher rates of anxiety associated with climate-related changes to their food supply.⁵⁰ Disruptions to fishing specifically in Indigenous communities have been shown to negatively impact community health and well-being.¹

Water shortages, also caused by climate-related events such as droughts, water-borne diseases, and human interference can increase tension between those who continue to have access and those who do not in affected communities.⁵⁰ Access inequity to food and water resources may undermine the integrity of a community and contribute to the long standing patterns of urban migration and marginalization, particularly of youth from rural communities.⁵⁰

Food- and Water-Borne Disease

Climate change may create unfavourable conditions that support the growth and survival of food-borne diseases and create pathways, such as polluted flood waters inundating agricultural fields, that could increase the risk of contamination of food products. The food-borne pathogens responsible for many of these illnesses are norovirus, C. perfringens, Campylobacter, and Salmonella.⁵¹ Due to the complexity of the relationship between food, food-borne illness, and changes in temperature and climate, it is difficult to determine specifically which food-borne pathogens will pose the greatest threat, what regions will be the most heavily impacted, and when.⁵¹ 

As climate change is creating heavier rainfall during the winter in BC, an associated increase in the emergence of water-borne diseases will become more evident. Additionally, drier and warmer summers will support the growth of various water-borne, vector-borne, and food-borne pathogens.⁵² The most common water-borne disease (WBD) pathogens in Canada are Giardia, Cryptosporidium, Campylobacter, Shigella and verotoxigenic E. coli. Changing ocean currents will bring these water-borne pathogens and contaminants towards the Northern Pacific and, coupled with the impacts on marine ecology due to rising temperatures, communities that rely on oceans and rivers for food and water will face greater contamination risks.⁵³ These risk are particularly concerning for vulnerable populations like children who are more susceptible to infections from food and water contamination.⁵⁴

Heat-Related Morbidity and Mortality

Between 1900 and 2013, records show that annual average temperatures in BC have increased by 1.4°C. Between 2013 and 2050, it is projected that an additional temperature increase will reach 2.7°C.²⁹ This concerning figure is almost double the temperature increase in less than half the time it took in the last century (Figure 6). Rising temperatures are not only a concern when considering climate events like drought and forest fire, but are also a threat to human health. As temperatures rise, so too do heat-related health conditions and illnesses. Heat-related morbidity and mortality are dependent on multiple factors, such as the frequency, intensity, and duration of heat exposure – all factors that are being exacerbated by climate change. Generally, the highest summertime temperatures and heat-related mortality in BC have been observed in the southern regions, most noticeably in the Southern Interior, a region of BC home to many rural communities.⁵⁵ Rising temperatures are especially a major threat to vulnerable groups such as infants and the elderly. For example, heat and air pollution have a greater synergistic effect on older populations.⁵⁶ All members of society, however, are vulnerable to the effects of temperature extremes. Men between the ages of 25 and 64, for instance, are vulnerable to occupational heat exposure, as they more commonly work outdoors during the hottest times of the day.

As an adaptation measure to increased heat, the Government of Canada has published guidelines to establish community-specific prevention, alert, and response planning to heat waves.⁵⁷ The Guide includes step-by-step toolkits on topics such as vulnerability assessment, relevant stakeholder engagement, alert system development, and examples of successful strategies.