Climate Change and Health

Climate change refers to long-term variations in weather conditions such as temperature and precipitation. It’s worth noting that climate change will affect both average conditions and increase the weather’s variability, meaning we will experience more extreme weather events. In Canada, climate change is expected to bring warmer temperatures, causing hotter summers, milder winters, and an increase in severe weather events like thunderstorms, hurricanes, tornadoes, wildfires, floods and droughts.

Health Impacts of Climate Change

Climate change is having an immediate impact on our health, including:

  • an increase in infectious diseases and emerging new infectious diseases
  • an increase in cardiovascular and respiratory diseases due to higher temperatures
  • an increase in the levels of pollen and allergens that can cause respiratory problems
  • worsening air quality

In the long run, Canadians can expect a higher incidence of physical health issues due to the deteriorating conditions brought on by climate change. A higher frequency of extreme weather events will also have adverse effects on the population’s mental health.

While everyone will feel the effects of climate change in the years to come, some people will feel them to a greater degree due to a variety of factors, including individual susceptibility, geographic location and socioeconomic status. For example, certain individuals could be more vulnerable to extreme heat events due to where they live (parts of cities may be warmer than others), characteristics of their dwelling that affect the inside temperature, as well as their age, fitness level, and other factors.

What is the EOHU Doing?

In 2016, the EOHU implemented a Heat Event Response Program that aims to reduce the risks of exposure to extreme heat by:

  • educating and raising awareness about heat-related illnesses
  • alerting those most at risk of heat-related illnesses that hot weather conditions are either imminent or currently exist and to take appropriate precautions

The EOHU is also working with community stakeholders on a Climate Change Health Vulnerability and Adaptation Assessment (CCHVAA). This project will assess and map communities’ vulnerabilities to climate change, identify health-related impacts, assess communities’ capacities to adapt, and inform the public and policymakers about the challenges and measures that can be taken to prevent or mitigate these impacts.

Why Is the EOHU Dealing with Climate Change?

The World Health Organization (WHO) has declared climate change as the number one threat to public health. The environment is a key determinant of human health, and climate change will have serious implications for our health and wellbeing.
Hence, the Ontario Public Health Standards (OPHS) requires health units to conduct assessments of their community’s health vulnerability to climate change in collaboration with community stakeholders. The information gathered is then used to integrate the required changes into public health’s daily work and support the public and decision-makers in the development of adaptation measures.
Since adaptation often involves proactive investment in the present to prevent greater losses and costs in the future, awareness is needed among the public and decision-makers.

What Can Community Stakeholders Do?

Many potential health impacts are linked to effects that occur outside the jurisdiction of the health sector. The EOHU’s partners in the community can help reduce climate change and prepare for its impacts by promoting active transportation, public transit and carpooling. Municipal agencies can also protect water sources by implementing policies to reduce water use, work to achieve targets for tree canopy coverage, and improve garbage and waste collection policies and programs.
If you are a municipal partner who is looking for more information or is interested in collaborating with the Health Unit on the CCHVAA project, please call the EOHU at 1 800 267-7120.

What Can Individuals Do?

Together we can Make it Better. We can all contribute to lessening the impact of climate change by doing our part and working together. Take the Make it Better pledge and learn how you can do your part by visiting the Ontario Public Health Association’s (OPHA) climate change website.


Health Canada – Climate Change and Health:

l Health Canada – Climate Change and Public Health Fact Sheets:

World Health Organization (WHO) – Climate Change and Health: