Comment les changements climatiques modifieront-ils notre santé?
Les sécheresses dans certaines parties du Canada pourraient bien
causer de sérieuses répercussions sur l'agriculture locale ainsi que sur
le mode de vie et les ressources des personnes affectées. De telles
perturbations ont des effets à la fois sur la santé physique et mentale.
Et ceci n'est qu'un exemple parmi d'autres.
La compréhension de ces effets sur la santé et le développement de
nouvelles politiques pour nous protéger des vagues de chaleur, des
tempêtes de verglas, ainsi que des nouvelles maladies devraient être des
composantes essentielles de notre système de santé.
Bien que le Canada ait planifié que la production des émissions des
gas à effets de serre serait réduite, notre climat va continuer à
changer et présentera encore des défis pour de nombreuses années.
West Nile Virus
Will a Changing
Climate Affect our Health?
Director of Environmental Research
New Brunswick Lung Association
have had a long, cold, snowy winter here in New Brunswick, and you may
have heard at least one person say, "What about Global Warming?
Bring it on!"
(photo: NB Lung)
Although the globe as a whole is expected to get
warmer, a few places might even get cooler. The reality is that a
change in our normal climate is likely to give us unusual weather,
such as more severe and more frequent storms, more droughts, and
unusually cold or unusually mild winters. These changes will have
effects on our health.
In over-simplistic terms, climate change is expected to increase
illness and death from familiar causes and increase the likelihood of
unfamiliar health outcomes.
Many parts of Canada are predicted to have more hot days
(technically, days over 30 C) each summer. This will have serious
consequences for infants, the elderly and people with lung and heart
diseases. The number of heat-related deaths is expected to increase.
People living in urban areas, especially in houses with inadequate air
conditioning, are vulnerable because buildings and pavement trap heat.
The positive side of temperature change is that winters may become
warmer in some locations, reducing the number of deaths from
Most of our production of greenhouse gases is from the burning of
coal, oil and gas in our power plants, industries and vehicles. These
actions also produce thousands of tonnes of other pollutants that go
into the air every year. Even though you often cannot see these
pollutants, they can seriously affect your health. Exposure to these
pollutants decreases the ability to breathe for people who have lung
and heart diseases. It can trigger asthma attacks, cause heart
attacks, lead to cancer, and it can cause premature mortality. A study
conducted by the Toronto Department of Public Health indicated that
almost 2000 people a year die in Toronto from air pollution (Basrur,
S.V. 2000. Illness Costs Of Air Pollution. Toronto Public
Health.) could put this reference below in a list of references, in
which case you would put (Basrur, 2000).
In many locations in Canada, hot weather goes hand in hand with
elevated levels of air pollution. In New Brunswick, our warm winds
blow to us from the central United States and Ontario regions. These
regions also have the most power plants and heavy traffic routes so
our warm winds carry pollution. As climate change results in more hot
days, we will also have more days with high levels of pollution.
Hotter temperatures also increase the chemical reactions that form
some air pollutants such as ground-level ozone. As well, it is likely
that people will turn up their air conditioners, thus increasing the
emissions from power plants. These factors combine to mean that we can
expect more air pollution during hotter days in the summer.
(Source: Gordon McBean, Institute for Catastrophic
Changes in the
distribution of plants and animals
A warming climate and changes in precipitation patterns will also
affect the distribution of plant and animal species other than humans.
These changes in geographical distribution could have a variety of
effects on humans, from changing the types of plants that can be grown
for food or for commercial uses, to increasing our exposure to certain
diseases (West Nile virus, Lyme's Disease) carried by animals
extending their range northward.
Storms and droughts
Climate change is expected to result in more frequent and more
violent storms. In the winter, severe ice storms can result in
injuries and death from hypothermia, carbon monoxide poisoning from
using inappropriate heating sources indoors or heart attacks from over
exertion while removing ice or snow. Hurricanes can cause injury from
damage to homes or falling trees, or even from drowning during sudden
flooding. Although certain areas may receive increased annual
rainfall, this rain may fall during more extreme storms and wash away
valuable topsoil, causing more damage than benefit.
According to the Institute for Catastrophic Loss at the University
of Western Ontario, "more than four million Canadians have been
affected by natural disasters in the last three years. The loss of
life and property from events like the 1996 Saguenay flood, the 1997
Red River flood and the 1998 ice storm in Quebec all warn about
Canada's growing vulnerability."
Droughts in certain parts of Canada may seriously impact local
agriculture and thus peoples' livelihood and food resources. Both
physical and mental health are directly impacted by these factors.
(Source: Gordon McBean, Institute for Catastrophic
Rising sea levels
Sea levels in eastern Canada may rise by about half a meter over
the next century, in part due to melting ice caps and in part because
the land mass is very slowly sinking. Higher sea levels together with
more frequent and severe storms may cause low-lying areas to be
inundated with water and coastal erosion to occur. Fresh water
resources of coastal communities may be contaminated by salt water.
Health impacts related to this include increased risk of drowning and
stress from loss of income from coastal investments and businesses.
Changes in temperature and precipitation patterns as well as rising
sea levels may make certain parts of the world uninhabitable. People
now living in places expected to be impacted by rising water or
drought may see New Brunswick as a safer place to live. An increasing
immigrant population may tax our health care system.
Northern Canada is particularly vulnerable to impacts of climate
change. Already the melting ice cap is causing homes to sink into the
softening permafrost and winter roads to be impassable. The resulting
socioeconomic impacts may well have significant impacts on the mental
and physical health of aboriginal communities.
According to the Intergovernmental Panel on Climate Change, it is
important to recognize that certain factors can modify the
vulnerability of a particular population to the health impacts of
climate change or variability. The sensitivity of a population depends
on factors such as level of urbanization, access to air conditioning,
and overall health status of the population. The federal government is
encouraging research on the impacts of climate change on Canadians by
supporting research networks across the country, called the Climate
Change Impacts and Adaptation research Networks (C-CIARN). The Health
networks are coordinated by the Climate Change and Health Office of
Health Canada. Although Canada has plans to reduce our production of
greenhouse gases to help slow down climate change, our climate is
expected to continue to change and present challenges for many years.
Understanding the health impacts, and developing new policies to
protect us from heat waves, ice storms, and new diseases are essential
components of the new health care system.
Between 1975-1995 and 2080-2100
Combined Effects of Projected Greenhouse Gas and
Sulphate Aerosol Increases - Canadian Model
(Source: Gordon McBean, Institute for Catastrophic Loss)
More detailed information on all of these topics can be found on the
website of the Intergovernmental Panel on Climate Change, www.ipcc.ch.