Understanding the Health Effects of Climate Change

Climate change is one of the greatest challenges of our time . . . and will affect, in profoundly adverse ways, some of the most fundamental determinants of health: food, air, water.  Dr. Margaret Chan, WHO, 2008

Climate change is affecting health, and will continue to pose challenges in the future. Because of Canada's large land mass, Canadians can expect a wide range of impacts which will vary from one region to another.

Environment Canada
New Brunswick

The extent of these effects depends on how quickly our climate changes, and on how well we adapt to the new environmental conditions and risks to health.

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How does climate change affect the health of Canadians?

Health Canada has identified seven categories of climate-related impacts, and the potential effects these can have on health and well-being.

Temperature-related Morbidity and Mortality

  • Illness related to extreme cold and heat events
  • Respiratory and cardiovascular illnesses
  • Increased occupational health risks

Weather-related Natural Hazards

  • Damaged public health infrastructure
  • Injuries and illnesses
  • Social and mental stress
  • Increased occupational health hazards
  • Population displacement

Air Quality

  • Increased exposure to outdoor and indoor air pollutants and allergens
  • Respiratory diseases
  • Heart attacks, strokes and other cardiovascular diseases
  • Cancer

Water- and Food-borne Contamination

  • Intestinal disorders and illnesses caused by chemical and biological contaminants

Vector-borne and Zoonotic Diseases

  • Changed patterns of diseases caused by bacteria, viruses and other pathogens carried by mosquitoes, ticks, and animals

Health Effects of Exposure to Ultraviolet Rays

  • Skin damage and skin cancer
  • Cataracts
  • Disturbed immune function

Socio-economic Impacts on Community Health and Well-being

A changing climate can increase the frequency, intensity or duration of extreme weather conditions which increases risks for vulnerable populations and communities in areas exposed to natural hazards.

  • Demands on Health Care Services - Extra pressure is placed on Health care services by increased demands resulting from weather-related natural hazards, eg. floods.
  • Disruption of Social Networks - Power outages can occur as a result of extreme weather-related events, which can affect our ability to communicate during emergencies.
  • Interference with Livelihoods - People experience stress if their livelihoods and productivity are threatened, for example, farmers suffering crop failures and income losses due to droughts.
  • Damage to, or unavailability of, housing and shelter - Climate change can increase the number of extreme weather events which can damage buildings. This causes trauma for people having to relocate, as occurred following the Saguenay River flood in 1996.
  • Damage to critical infrastructures - Virtually all our infrastructures are designed for a specific climate, such as those related to food production, water management, energy production, storm sewer, drainage and sanitation systems, and housing and health infrastructures. Health risks can arise when any one of these systems fails or becomes compromised - as they may in a changing climate.

As an illustration, severe weather events can result in loss of income and productivity, relocation of people, increased stress for families, and higher costs for health care and social services. The 1998 ice storm, for example, was responsible for 28 deaths in Canada. Over 1.6 million Canadians were affected by electrical power failure, 2.6 million people could not perform their ordinary work, and economic losses amounted to $5.4 billion.

Who will be most affected by a changing climate?

A good understanding of who is most likely to be impacted by the effects of a changing climate, advances adaptive actions to minimize the impacts. More vulnerable groups include:

  • Children
  • Seniors
  • People who are chronically ill
  • Low income and homeless people
  • Disabled people
  • People living off the land
  • Northern residents

Will there be any benefits to climate change in Canada?

Some communities could experience benefits from global warming. For example, some regions may enjoy a longer growing season, and milder winters which could result in fewer injuries and deaths associated with cold weather.

The realization of specific benefits or negative impacts is largely dependent upon the rate of climate change, and Canada's ability to adapt to the effects of a changing climate.

There are  health benefits from reducing greenhouse gas emissions. By decreasing the burning of fossil fuels, we not only reduce our emissions of harmful greenhouse gases, but can also lessen the release of toxic pollutants known to affect the health of people and ecosystems.

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