Environmental Issues in Northern Ontario
The Science of Climate Change
Climate change is a shift in the “average
weather” that a given region experiences. This is measured by changes in
all the features we associate with weather, such as temperature, wind
patterns, precipitation, and storms. Global climate change means change
in the climate of the Earth as a whole. Global climate change does occur
naturally the ice age is an example. The Earth's natural climate has
always been, and still is, constantly changing. The climate change we
are seeing today differs from previous climate change in both its rate
and its magnitude.
The temperature on Earth is regulated by
a system known as the “greenhouse effect”. Greenhouse gases primarily
water vapour, carbon dioxide, methane, and nitrous oxide trap the heat
of the sun, preventing radiation from dissipating into space. Without
the effect of these naturally occurring gases, the average temperature
on the Earth would be -18° C, instead of the current average of 15°.
Life as we know it would be impossible.
Over the past 200 years, emissions of
these gases due to human activities have accumulated in the atmosphere,
where, because of their long life, they stay for anywhere from decades
to centuries. As a result, since the Industrial Revolution,
concentrations of carbon dioxide have increased by 30 per cent, methane
by 145 per cent, and nitrous oxide by 15 per cent.
The cause of these increases has been human activities related to our
increasingly sophisticated and mechanized lifestyle, in particular the
burning of fossil fuels such as coal, oil, and natural gas to generate
electricity and in factories and cars. As well, we have cleared more
land for human use in the past 100 years than in all of prior human
history. This has resulted in the loss of forests and wetlands, which
absorb and store greenhouse gases and naturally regulate the atmosphere.
In effect, by increasing the amount of
these heat-trapping gases, we have “enhanced” the natural greenhouse
effect to the point that it has the potential to warm the planet at a
rate that has never been experienced in human history. Already, the
average global temperature has increased by about 0.5° C in the past 100
years, and temperature increases over the next 100 years are expected to
significantly surpass any such change of the past 10,000 years.
Trends in CO2 Concentrations (Past 1000
Years)
Raising the global temperature may trigger a series of changes within
the overall global climate system. For instance, global sea levels have
risen 10-25 cm over the past 100 years, and are expected to continue to
rise due to increases in temperature. We are also seeing increases in
severe weather events. Such impacts of climate change could have
far-reaching and/or unpredictable environmental, social, and economic
consequences. Indeed, the climate change problem and the related changes
it may bring about are among the most serious of the environmental
issues that we face today.
Future Projections
Scientists have been able to make some
projections about how greenhouse gas concentrations may change over the
next hundred years, based on a range of scenarios.
The most extreme scenario is based on an
assumption that high economic growth will continue, and that humans will
continue to use coal, oil, and gas globally for their energy needs. This
scenario suggests that concentrations of carbon dioxide could reach more
than three times pre-industrial levels by 2100. Even the most hopeful
scenario based on low growth in global population and intensive
conversion to renewable energies suggests that carbon dioxide
concentrations would be about 75 per cent higher than pre-industrial
levels by 2100, and would continue to rise thereafter. Stabilizing
global emissions at 1990 levels now would have the same effect, because
of the long life of these gases in the atmosphere.
Canadian scientists have developed one of
the most advanced climate models in the international research community
to determine what these projected increased in greenhouse gas
concentration could mean. Their research suggests that average global
surface temperatures could increase on average by almost a half degree
each decade during the next century.
Projected
Temperature Change between 1910 and 2040 AD
Combined Effect of
Projected Greenhouse Gas and Sulphate Aerosol Increases. Canadian Model
To provide an idea of what that means, global warming over the next
century could be as great as the change in temperature between the peak
of the last ice age, some 25,000 years ago, and today.
Stabilizing greenhouse gases is only a
part of the solution, though. Scientific projections also indicate that,
even if the concentrations of greenhouse gases were stabilized by 2100,
air temperature could continue to increase. As well, sea levels, which
are expected to rise anywhere from 15 to 95 cm by 2100, could continue
to rise at a similar rate in future centuries. This would be the case
even after concentrations of greenhouse gases had been stabilized, and
even after global mean temperatures had stabilized. This is because of
the long time it takes oceans to heat up before they fully respond to
increased air temperatures.
Potential Impacts of Climate Change
There is little doubt about the
significance of these projections. In general, all available models
agree that warming will be greater in Arctic regions than in equatorial
regions, and that continents will warm more than oceans. Beyond this,
however, scientists are not able to predict the exact consequences of
continued increases in greenhouse gas concentrations or its impact on
specific regions.
As a northern country, Canada will likely
warm more than many other countries. These warmer temperatures could
provide some benefits longer growing seasons in the summer, less demand
for heating in the winter. But these benefits will come at a cost and,
without strategies in place to adapt to the changes, we may miss out on
the benefits entirely.
As well, Canadians may be better equipped
to deal with the impacts of climate change than many parts of the
developing world, where existing environmental and ecological problems
could be worsened. This could have costly implications for geopolitical
security and foreign aid.
Around the world, climate change is projected to:
- threaten the world's boreal forests
with an increased fire risk because of the drying climate;
- cause water needs to outstrip supply;
- cause severe water loss due to changes
in evaporation and precipitation patterns;
- cause flood damage to low-lying
countries and island states, including loss of coastal land to rising
sea levels;
- urage the movement of tropical
diseases such as malaria northward, where populations have little or
no immunity; and
- affect international trade patterns.
The consequences for Canada arising from
these impacts on the international community, particularly our trading
partners and competitors, will be substantial.
In Canada
We are likely to see changes in our
ability to grow food and potential costly changes to the methods we use
to do it. Warmer temperatures could create conditions for more severe
weather events, including thunderstorms and an increased frequency of
tornadoes, with attendant risk to life and property. Drier conditions
and warmer temperatures could also cause more frequent forest fires.
More frequent heat waves could affect the health of Canadians,
especially in cities.
Higher air temperatures and removal of
the insulating vegetative cover could lead to a melting of permafrost in
the Arctic. This could cause more landslides in some areas, and problems
for the construction and maintenance of pipelines, roads, and bridges.
Glaciers could retreat more quickly because of higher air temperatures,
resulting in less late season runoff, and placing fish habitats and
water supplies in dependent communities at risk.
Canadian scientists have examined the
potential impact of climate change on human health and our environment,
including our water resources, fisheries, forests, wildlife, and
ecosystems. They have projected what climate change could hold for each
of these aspects of our environment, recognizing that the rate of
change, as well as the number and severity of extreme weather events,
will affect the magnitude of the impacts and our ability to cope with
them.Their projections for different aspects of our environment are
provided below.
Potential Impacts of Climate Change on
Water Resources
Because water plays a central role in
many economic and societal functions, the implications of climate change
for water resources are key to defining overall impacts. Climate change
is expected to directly affect both the quantity of water available and
its quality, creating competing demands for this resource from multiple
sectors.
Potential Key Effects
Water levels in the Great Lakes and St.
Lawrence River are expected to decline. Major impacts include: a
decrease in both groundwater and surface water; concerns regarding
integrity and quality of the shoreline and associated facilities; and a
decrease in shipping capacity. In 1964, low water levels caused a $35
million loss for Great Lakes shipping and hydropower, and one-third of
municipalities along the lakes had water supply problems.
Projected sea-level rise will generally contribute to deeper drafts in
marine harbours and channels, but could lead to significant damage to
coastal support infrastructure. The potential of increased storm
activity has raised concerns regarding the necessity of increased
navigational aid support.
In the Prairies, the projections of
increased temperature, decreased snow pack with an earlier melt season,
and a more vigorous hydrological cycle are of particular concern in
terms of their implications for water availability and soil moisture, as
well as the frequency and intensity of floods and droughts. The 1988
drought on the Prairies resulted in a 31 per cent reduction in grain
production and export losses of $4 billion.
Projections of water availability and
flows suggest differentiated impacts on hydroelectric generation
potential, with possible increases in Labrador and northern Quebec, and
possible decreases in Ontario, the Prairies, and southeastern British
Columbia.
Impacts of Climate Change on
Fisheries
Climate change can be expected to have a
significant impact on fisheries in Canada affecting both the
productivity of fish populations and how they are distributed throughout
lakes, streams, and oceans. Changes to water temperature, currents,
water quality, food supply, and predators could all have effects on fish
populations.
Potential Key Effects
The freshwater fishery is mostly a
subsistence and recreational fishery. Change to the distribution of
highly prized species would have an effect on the recreation fishery
industry, with possible losses occurring in some areas. In general, as
lake and stream temperatures warm, species at the warmer southern limit
will either die or migrate northward to more favourable habitats. Cool
and cold-water freshwater fish populations, including species such as
trout, whitefish, and grayling, could be reduced in many lakes and
streams on the Canadian Shield due to declining water levels and flow
and reductions in nutrient loading and recycling.
Freshwater fish species that currently
live at the northern limit, or cold-water limit, of their preferred
habitats in larger lakes will likely benefit from warmer water
temperatures, experiencing increased survival and growth.
Growth rates, age of sexual maturity, and
distribution of some marine fish species are sensitive to water
temperatures. Cooler temperatures could typically result in delayed
spawning and a shift in distribution southward, while warmer
temperatures could result in earlier spawning and a shift in
distribution to the north.
In the Pacific, the abundance of the
southern salmon populations are expected to decline, as are those of
Pacific cod. Higher, more consistent sustainable harvests are
anticipated from northern salmon populations, with Sockeye salmon most
affected.
Impacts of Climate Change on
Forestry
A general trend towards warmer conditions
combined with increasing levels of carbon dioxide could increase forest
distribution and growth in Canada. It could take decades, or even
centuries, however, before forests adjust to new climatic conditions.
During this period of adjustment, the boreal forest in particular could
be more vulnerable to insects and diseases, forest fires, and
competition from unwanted species, and the forestry industry will have
to adapt to new climatic conditions. The rate of change, as well as the
number and severity of extreme events, will dramatically affect the
magnitude of impacts and our ability to cope with them.
Potential Key Effects
If carbon dioxide levels were to double,
the Taiga and Boreal forest belts could shift northward by about 500 km.
However, it would not be the Taiga or Boreal forest as we know it that
would move northward, but rather the more fast-moving flexible species
such as those with wider seed dispersal, faster growth, and early
maturation.
The boreal forest itself is expected to
undergo an extensive reduction in size, as grasslands and temperate
deciduous species may invade from the south, and northern expansion is
limited by poor soils and insufficient sunshine amounts. Forest fires
and pest infestations are expected to increase in frequency, area, and
intensity due to warmer and drier conditions. Increased fire incidence
will lead to loss of habitat for species that inhabit mature forests.
This may be eased by changes in fire management policy in order to
facilitate species migration and forest adaptation, but this would
require significant investment. In 1994, Canada lost four million
hectares of forest to fires. Since 1980, Canada has lost an average of
2.4 million hectares of forest to fires each year, a 140 per cent
increase over the previous 30 years.
Within the Temperate Conifer zone of
British Columbia, forests could shift upward in elevation and, under the
worst scenario, disappear entirely from some zones due to a lack of
winter cooling for forest regeneration, drought, stress, and increased
sensitivity to spring frosts.
Changes in Forest and
Grasslands Boundaries
Impacts of Climate Change on Health
Climate change could affect the health of
Canadians due to higher temperatures, more frequent storms, and
increases in air pollution episodes. Changes in the transmission of
insect- or water-borne diseases could also have an impact on Canadians'
health. As well as affecting the health of individual Canadians, these
projected changes would place additional stresses on the
health-infrastructure and social-support systems.
Potential Key Effects
The World Health Organization has warned
that heat stress and climate-induced respiratory problems as a result of
reduced air quality could occur in large urban areas, and could lead to
increased death rates.
Warmer temperatures and shorter cold seasons could allow
disease-carrying hosts to survive at locations further north than at
present. Two commonly mentioned diseases are Rocky Mountain Spotted
Fever (in the U.S.) and Lyme disease. Mosquito-borne diseases such as
malaria and encephalitis could expand into Canada, presenting a
challenge for our health care system.
Changes in ecosystems may also affect the
supply of foods available to those who depend on hunting and gathering,
such as the aboriginal people of northern Canada. Changes in ecosystems
may allow different species of plants to flourish, possibly causing
problems for asthma and allergy sufferers.
Impacts of Climate Change on
Infrastructure
The threats posed by climate change to
Canadian infrastructure are many and varied, with significant
environmental, social, and economic implications. Some anticipatory
measures, such as greater flood control and larger water reservoirs, can
be undertaken, but these have social and economic costs of their own.
One important measure would be to base new construction on engineering
standards revised to take account of changing climate.
Potential Key Effects
In Canada's North, melting permafrost
will likely affect infrastructure and transportation, including the
integrity of foundations (pipelines, bridges and buildings), water
control structures, ice-roads and, the melting of the assumed
impermeable permafrost beds of mine-tailing ponds and landfill sites.
Higher sea levels could increase coastal
erosion and damage from storm surges, and present problems for coastal
infrastructure such as harbours, water supplies, and sewage disposal
systems. Most of the coast of Prince Edward Island is highly sensitive
to the impact of sea-level rise due to its low relief and bedrock. The
current sea level rise of 3.5 mm per year is already causing erosion
problems in some areas. The coasts of southwestern BC and the Beaufort
Sea are also sensitive to sea level rise.
Projected changes in rainfall intensity and snowmelt runoff could
increase the potential for flooding in water basins, with over-tipping
of dams, culverts, and flood control structures. Projected increases in
rainfall intensity could change the patterns of flooding in Canada,
requiring adaptation of flood-prevention infrastructure. In addition,
the occurrence of spills from urban sewage systems is likely to
increase.
Human settlements and infrastructure are
especially vulnerable to extreme weather events. In 1996, floods and
hailstorms cost an estimated $1.5 billion in damages to homes, business,
and infrastructure.
Impacts of Climate Change on
Tourism and Outdoor Recreation
Changed weather patterns could mean
differences in how Canadians enjoy our outdoors. But climate change's
projected impact on the tourism and recreation sector can be offset by
measures such as relocation of facilities, application and improvement
of technology, and the development of multi-season recreational centres.
These are all occurring to varying degrees at present.
Potential Key Effects
Hunting of game and waterfowl is likely
to feel the impact of climate change as wildlife may be displaced due to
habitat loss, altering community structures, or increased competition.
Wetland habitat in particular could be significantly altered both in
quantity and quality.
Recreational fishing may be locally disrupted by lower water levels in
lakes, declining flow rates in streams, warmer temperatures, and
reductions in nutrient loading.
The season for outdoor activities in winter will likely be shorter,
especially in more southerly latitudes. Existing ski resorts may have to
rely increasingly on artificial snowmaking to maintain the season.
Impacts of Climate Change on
Wilderness
Climate change poses significant threats
to unmanaged ecosystems in Canada, including wetlands, permafrost areas,
and the Southern Arctic Ecozone. Some preventive measures can be taken
to offset these threats, but overall, human intervention will be
necessary to minimize or adapt to the anticipated effects of climate
change. One vital need, for example, is for increased intervention to
reduce the risks posed by landslides and debris torrents in mountainous
areas.
Potential Key Effects
Altered precipitation and temperature
regimes could affect the seasonal pattern and variability of water
levels of wetlands, thereby affecting their functioning including flood
protection, water cleansing and waterfowl/wildlife habitat.
Projected losses in prairie pothole wetlands will have a negative impact
on domestic and migratory wildfowl and aquatic populations. These
wetlands currently yield 50 to 75 per cent of all waterfowl produced
annually in North America. Trends in duck abundance already reflect the
interactions between changing wetness regimes and landscape alteration;
additional stress (e.g., from climate change impacts) would be of
considerable concern.
Affected peat lands in the north that currently are sinks where
atmospheric carbons accumulate, are predicted to become sources of
atmospheric carbon, and are projected to disappear from south of 60 in
the Mackenzie Basin, though their number may increase further north.
Patchy Arctic wetlands, currently supported by surface flow, may not
persist. Lakes and ponds, which have permafrost hydrologic divides, are
more likely to drain laterally on to the groundwater system,
dramatically altering hydrology and dependent ecosystems.
Loss of breeding and forage habitats for
migratory wildfowl and mammals may occur within the Southern Arctic
Ecozone, which is projected to all but disappear from mainland areas.
This ecozone, which contains the Queen Maud Gulf Lowlands and is
currently the home of a significant proportion of the Inuit population,
is the major breeding and nesting ground for a variety of migratory
birds. As well, it is the major summer range and calving grounds for
Canada's largest caribou herd, and provides habitat for bear, wolf,
moose, arctic ground squirrels and lemmings.
New scientific findings released by the
Intergovernmental Panel on Climate Change (IPCC) provide new and
stronger evidence that most of the warming observed over the past 50
years is attributable to human activities. You can consult the following
reports: Climate Change 2001 - Mitigation; Impacts, Adaptation and
Vulnerability; The Scientific Basis.
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