Effects on Health and the Environment

Climate change is more than a warming trend that will continue to produce milder winters and longer summers for Canadians. While warming patterns, precipitation and extreme weather events will vary from region to region, one thing is certain. Climate change will have negative implications on the environment and our health.

Health

Increasing temperatures and greater variations in weather mean that the health effects from climate change will vary from region to region. Young children, the elderly, people in poor health or those living in poor quality housing will be most vulnerable to stresses related to weather extremes such as poor air quality, infectious diseases, allergies and poor water and food quality.

Heat-related Diseases

In Canada, climate change will mean that we will experience shorter and milder winters. Climate change scientists similarly conclude that over the coming century, we can expect hotter summers with heat waves that occur more frequently, last longer and have higher levels of humidity.

More intense heat waves will perpetuate many heat-related illnesses such as heat stroke and dehydration. 

Air Quality

Warmer temperatures and prolonged heat waves combined with an increase in VOCs (volatile organic compounds) in our urban and industrialized areas will contribute to poorer air quality and more smog. This is because ground-level ozone is created when sunlight interacts with VOCs, which are produced from burning fossil fuels (such as vehicle exhaust). Ground-level ozone is a primary ingredient of smog which has been linked to increases in both the rate and severity of respiratory diseases.

Children are especially vulnerable to air pollution: they are smaller in size and their lungs are still developing, they also tend to spend more time being active outdoors when compared to adults. Hotter, more humid weather will pose special health risks for children who already suffer from asthma. Changes in wind and weather patterns can also alter the amount of fungi, moulds and pollen in the air, affecting people with allergies.

Infectious Diseases

Warmer temperatures will increase the range of some parasites and the diseases transmitted by insects and ticks possibly bringing new infectious diseases to communities they would not otherwise reach. A prime example is the recent and extremely rapid spread of West Nile virus across the US and Canada. Climate change may also favour the northward spread of mosquitoes capable of transmitting dengue fever, yellow fever, and malaria.

Water and Food Quantity and Quality

Warmer temperatures also mean lower water levels in our lakes, and warmer bodies of water, which are breeding grounds for microorganisms that threaten our health. In Eastern Ontario, there are already cases of recreational beaches having to close each year for weeks at a time due to outbreaks of microorganisms that not only can cause infections and rashes, but can also increase chances of food poisoning in sea life (shellfish) and local game that drink from these bodies of water.

Scientists have concluded that during the next 50 years heat-related deaths will increase, particularly in large cities in southern Canada where our green spaces continue to be replaced by buildings which trap heat through roofs and walls, making our cities feel even hotter. We must take adequate measures to protect vulnerable individuals and to reduce the effects of climate change.

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Environment

Extreme Weather Events

A warmer climate is likely to cause more frequent and more intense severe weather events, such as hurricanes, tornadoes, thunderstorms, floods and droughts. These events have many potential health impacts, including direct physical injury or death, psychological distress due to the loss or injury of loved ones and property, mass evacuations and homelessness.

Although it is not possible to link recent severe weather events directly and solely to climate change, the following historical examples suggest the types of risks to health and well-being that Canadians may continue to face.