The environment is the physical, social and psychological milieu in which we exist, which affects us and is in turn affected by us. Throughout its 4-billion-year history, profound changes have occurred in the geological and ecological systems of Earth. As long as human populations remained small and communities were part of local ecosystems, most changes took place slowly and seemingly without major disturbances in the global system.

Deforestation, soil erosion and salinization, and in some cases climate change contributed to the collapse of many ancient civilizations around the world. The exponential growth of the human population and the extensive industrialization of the last 200 years, however, have placed stresses on the complex processes that maintain the stability of the biosphere (the relatively thin but highly complex layer on and above the surface of the planet consisting of the atmosphere, water, minerals and organisms).

Disturbances in one part of the biosphere do not necessarily remain localized but can affect its composition and stability elsewhere (see Biogeography). Thus the release of chlorofluorocarbons (CFCs) in the Northern Hemisphere has thinned the ozone layer over the South Pole (see Ozone Depletion). Sulphur compounds produced by industrial activity in the United Kingdom and continental Europe have caused a marked decline in the biological productivity of lakes in Sweden, while deleterious changes in lakes in Ontario are attributable to pollutants from the US and from Ontario itself (see Acid Rain).

The list below is not exhaustive, but some of the more important issues affecting the environment of concern to Canadians are discussed.

Population and Development

The size, growth rate and resource use of human populations are contentious and complex factors affecting the environment. With a population approaching 34 million, a population density of less than 4 people per square kilometre and a national birthrate less than that needed for replacement, Canada is relatively well endowed with land, water and other natural resources. Canada's 9.98 million km2 of surface area (land and water), seemingly abundant water supply, and large open spaces perpetuate the myth that Canada's resources are limitless. There is, however, no straight-line connection between overall population and the availability of resources in any country. Canada is no exception.

Population density and population growth rates are variable across the country and the regions of high population density are often not the regions that have abundant supplies of critical resources such as water. Western cities such as Calgary and Edmonton saw large increases in population due to the economic boom in Alberta in the 1990s and early 2000s. Yet, these cities will likely experience shortages of water due to a mix of human demands and associated declines in water quality and availability. In Ontario, populations of urban areas have grown rapidly due to the concentration of immigrants in the larger cities - cities that have expanded geographically at the expense of prime agricultural land in those regions. Last, the regions with the highest population growth rates and lowest population densities - northern communities with large Aboriginal populations - often suffer from a shortfall of access to basic human needs such as clean water and adequate housing.

Resource Use

The belief that our land base and resources are without limit has, until recently, so dominated Canadian thinking that protection of the environment and conservation of renewable and non-renewable resources has been difficult to promote.

Water is an excellent example of this type of persistent fallacy, in which various authors have suggested that Canada has one-fifth of Earth's fresh water without providing any further details. The average does not mean much without consideration of distribution. About 60% of Canada's water drains north, while 90% of the population lives within 300 kilometres of the Canada-US border. Five of six potentially water-deficient areas in the country are located in the more arid regions of Canada that, ironically perhaps, are dominated by agricultural land uses that rely on water. These areas include B.C.'s Okanagan Valley, southern Ontario, and the primary agricultural areas of Alberta, Saskatchewan and Manitoba.

The value of irrigation is very well established in the 4 western provinces. However, the large flows in rivers in other parts of the country (Mackenzie, St Lawrence and Fraser) cannot be much use in extending the supply of the resource, which is limited on the Prairies.

Canada is fortunate in having water and sewer services in almost all urban areas. But the low cost of the supply and waste disposal and the political popularity of postponing unpopular taxes and service charges has led to major problems. One is that Canadians are very heavy water users. Residential water users use on average more than 300 litres per person per day (although some municipalities in Canada report using more than 1000 litres per person per day; in general smaller municipalities use more per capita than larger municipalities), compared to about 139 litres in Japan and less than half that amount in England, Denmark and Germany.

Modest efforts at conservation could easily cut this usage by 20-25%. Not only would there be savings in capital expenditures for water and waste water treatment systems, but operating costs would be reduced. It is estimated that about 13% of municipal water lost is due to aging infrastructure. Yet, the cost to repair and upgrade the infrastructure is high and Canadians continue to pay relatively low rates for water usage. As long as Canadians are supplied with water below cost because of large hidden subsidies, water conservation will be difficult.

Water pollution remains an issue in many watersheds because of the well-established principle and practice of using the "assimilative capacity" for waste of bodies of water as a resource to be exploited. Because such capacity is difficult to assess, varies with conditions, time of day and season, and volume of flow, and is generally very poorly managed, pollution problems persist. Furthermore, water pollution cannot be completely controlled until air quality is managed effectively. This is particularly the case with acid rain. Some water pollution problems have been reduced. Heavy metals such as mercury and lead have steadily decreased in water supplies throughout the country. Some persistent organic pollutants (such as PCBs and dioxins) have been decreasing in many fish populations, but such toxic materials are increasing in upper trophic levels in the Canadian Arctic.

Other Renewable Resources

Renewable resource-based industries (agriculture, forestry, fisheries, tourism and hunting and trapping) are very important to the Canadian economy but face severe problems. Agriculture, forestry and fishing are suffering because of long-standing practices and policies emphasizing short-term returns at the cost of long-term stability based upon sustainable yield. The renewable resource industries have not been subjected to the same government pressures as mining, energy and chemicals and have been much slower to introduce effective environmental and resource conservation constraints.

Canadian agriculture faces soil degradation, loss of high-quality land to other uses, and demands for constraints on chemical pesticides and fertilizers because of real and imagined health problems. Canadian forestry has been managed like a nonrenewable mining operation: only about 25% of the area cut has been reforested. Basically, all of the Atlantic hardwood forests are gone, and 90% of the southwestern Ontario resource has been cut. Two-thirds of the West Coast temperate rainforest has been cut, and much of what remains is difficult to access or is under demands for preservation or dedication to other uses or users. Allowable annual cuts had to be reduced in several provinces. Fisheries have been closed, or catches reduced on both the East and West coasts.

Although multiple use of resources such as air, water and forests is beginning to be practised, established practices for misuse and single-purpose use persist because these resources are largely undervalued, and because there are no effective and binding mechanisms for resolutions of disputes between users. This has been the case in areas where water resources have been dedicated to hydroelectricity generation or irrigation. In these industries, construction of reservoirs, diversions and delivery systems have been increasingly subjected to formal environmental impact assessments. But other uses, particularly instream uses such as recreation, fish, wildlife, waterfowl and aesthetics, often cannot compete.

Non-renewable Resources

The mining, mineral processing and smelting industry has been an important contributor to the Canadian economy but at heavy cost to the environment. Lead, zinc, copper and nickel have contributed to acid rain and other water and air pollution problems. Gold mining and refining has contributed to very severe water pollution problems and to the devastation of watersheds through placer mining. Uranium use is characterized by all the problems associated with exposure of workers and with radioactive wastes. Aluminum is produced at the cost of air pollution and the destruction of natural environments because of the high demands for cheap hydroelectric power.

The extraction of oil through the oil sands (see Bitumen) projects in northern Alberta has contributed to the physical destruction of large tracts of land as well as pollution of air and water resources. Overall the oil and natural gas sector in Alberta uses 8% of all water allocations, including 37% of groundwater allocation. This may seem small, but companies in northern Alberta are allowed to divert more than twice the volume required to meet the annual municipal needs of the city of Calgary. Again, the geography of use is important in understanding environmental effects.

These industries have taken steps to reduce their impacts on the environment and to improve their image. The Mining Association of Canada's program, Towards Sustainable Mining, has a set of environmental protocol and performance indicators for its members. The chemical industry has a similar program, Responsible Care, which was started in Canada in 1985 and is now in place in more than 50 countries. The Canadian Association of Petroleum Producers (CAPP) has a mandatory Stewardship program for its members. The Coal Association of Canada and many of the electricity utilities are working hard on environmental problems, although there is still ample ground for improvement.

Endangered Species

The extermination of species is inexcusable on moral, ethical and even economic grounds because of the loss of ecological and genetic diversity (see Biodiversity). A more ominous concern is the fact that loss of species indicates a lack of control over change. Coal miners used canaries to check on air quality: the death of a bird was a warning to the miners. So the loss of species should be taken as a warning of deteriorating environmental quality.

Since its inception, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) has examined more than 800 plant and animal (including insect) species and concluded that approximately 600 of these are either extinct or are at risk. There are more than 1000 additional species still in need of assessment. Species have been considered at risk due to a range of activities including hunting, physical alteration of habitat (through activities including agriculture, mining, urbanization, forestry, introduction of alien species, fire suppression, water removal and the building of dams and transportation corridors), as well as chemical and climate changes through industrial processes and transportation.

There are programs to re-establish viable populations of species that were or are extirpated (swift fox and black-footed ferret) or endangered (whooping crane), but re-establishment of viable populations requires the provision of safe, secure and biologically-rich habitats; and a large enough gene pool that the species can thrive. Programs to protect species can be successful, as shown by the fact that some species, such as the eastern bluebird, have been removed from the endangered species list.

The most significant threats to wildlife are those involving habitat loss, alteration and fragmentation, especially if wildlife are unable to move to a more suitable habitat because it is just not available; they will not or cannot migrate (especially in the case of plants); or because migration corridors are not available. Climate change is also likely affecting the habitats of many wildlife species. Both the habitat and pollution problems also have international aspects for species that migrate and because air- and water-borne pollutants move across borders.

Domestically, the protection of habitat must be provided through the system of national and provincial parks and other protected areas through legislation. Efforts to protect species at risk through the establishment of parks and protected areas may fail if these areas do not have suitable habitat or are not large enough to support populations. The federal government's Canadian Environmental Assessment Act (1992), which aims to identify and recommend protection for important habitats threatened by large development projects (such as megaprojects), will also continue to play a key role (see also Endangered Animals; Endangered Plants).

Parks and Protected Areas

There were early efforts to protect the more scenic parts of Canada's environment as a result of attempts by the Canadian Pacific Railway in the mid-1890s to develop a tourist industry in the Canadian Rockies. In 1887, the 1885 Order in Council, which had established the Rocky Mountain National Parks (later Banff and Jasper), was formally passed by Parliament and given Royal Assent.

Canada's national parks play a key role in protecting natural areas for future generations. Some areas have been removed from the parks so that they could be exploited for commercial interests. Federal ministers have sometimes suggested that parklands be opened to forestry and mining operations and to increased commercial recreation development. In the 1990s and 2000s, budget cuts severely restricted the ability of Parks Canada to fulfill its mandate to achieve ecological integrity within its areas of jurisdiction. Despite these cuts, the national parks system has been steadily expanded, particularly in northern Canada. Canada also has a system of marine protected areas (see National Marine Conservation Areas); however, their designation has been slower than that of land-based regions.

Lands and habitats are also protected, to varying degrees, under provincial park systems. BC, for example, has been vigorous in its establishment of protected areas, with just over 12% of the land base established as protected area. Non-governmental organizations have also been important in protecting habitats and biodiversity. For example, Ducks Unlimited Canada works with landowners and other organizations to identify important habitats and to establish livelihood activities that do not jeopardize important nesting, rearing or overwintering habitat for bird populations. Canada supports a network of United Nations Biosphere Reserves that also attempts to combine environmental protection with livelihood protection.

In contrast to the wilderness areas and protected habitats in rural areas, there are parks located in Canada's cities (see City Parks). Most major cities have very large natural parks: Vancouver's Stanley Park and the Endowment Lands, Edmonton's North Saskatchewan River valley, Calgary's Fish Creek and Nose Hill parks, Toronto's Toronto Islands and Montréal's Mont Royal. Such large natural areas within metropolitan centres are important in providing recreational opportunities for the relief of stress without the necessity of travel. They also provide essential educational opportunities as well as habitats for wild species that live near human habitation.

Solid Waste

Canadians generate more than 2 kg of solid waste per person per day. This is one of the highest volumes of waste per person in the world. In comparison, waste generated in Sweden is estimated at less than one-third that of Canada. About one-third of the solid waste generated in Canada is household garbage (see Solid Waste Management). This very high level of waste has been established because of relative affluence and high wages that make low-value, labour-intensive processes prohibitively expensive; low population densities and long distances between centres where waste is generated; low waste disposal costs; very cheap raw materials and the myth of infinite resources; and an economy that is supported by government policies and strategies that emphasize exploitation of natural resources and material consumption.

In 1989, federal and provincial leaders agreed that Canadians would reduce solid waste by 50% of 1988 levels by the year 2000. At the end of 2000, Nova Scotia was the only province that had reached that goal. The lack of well-established recycling industries and markets for recycled materials still prevents much of the public from acting on their declared willingness to reduce waste through recycling. Some mid-sized cities, like Saskatoon, still lack public curbside recycling. In fact, with recycling, not only would the solid waste problem be reduced, but the energy demands and environmental damage of producing the raw material in the first place would also be saved. (See also Waste Reduction.)

Numerous studies have identified the loss of organic matter in soils as an increasingly serious problem for agriculture in Canada. Unfortunately, this problem has yet to be linked to the large volume of compostable wastes creating economic and environmental problems for many municipalities. Advances in composting techniques and technologies at research centres, such as Olds College in Alberta, provide the means of turning organic wastes into soil amendments and other products.

Hazardous Waste

The Canada Environmental Protection Act lists classes of chemicals on a priority substances list for stringent control. There are waste sites all over Canada (particularly Ontario and Québec), including military sites in the Arctic. Alberta has a special waste treatment facility at Swan Hills which received its full operating licence in November 1988. Programs such the chemical industry's Responsible Care and the federal government's National Pollutant Release Inventory (NPRI) are recording reductions in the release of pollutants.

A very important environmental concern about hazardous waste disposal centres on the storage of nuclear wastes. There is an ongoing and acrimonious debate about how nuclear wastes should be handled in Canada, if indeed the generation of such wastes should continue at all. Of course, even if the answer to the last question were no, existing wastes would still have to be dealt with.

The mining industry remains a source of significant hazardous wastes. It is estimated that there are at least 10 000 abandoned mines in Canada, including uranium mines. Cleanup of these sites would require several billions of dollars and in many cases, responsibility has been left with provincial governments as the previous owner or operator of the property can no longer be identified or is unable to pay.

Protection for the environment could be provided by establishing "zero discharge" as a long-term goal for persistent toxic substances (PTS). PTSs are those chemicals that are toxic and do not decompose, or decompose very slowly, in the natural environment. Zero discharge means stopping the release of PTS to the environment by eliminating them in wastes and in products.

All levels of Canadian society are able to exert some control over decisions that affect the environment.

Public Opinion

Political and public opinion polls in Canada have shown that although environmental issues have been relatively high on the list of concerns of Canadians for the last few decades, environmental concerns appear to rise and fall during political elections. Environmental organizations (see Environmental and Conservation Movements) often play an important public service role in reminding Canadians of significant environmental issues related to a range of issues including water quality, resource extraction, waste management, biodiversity protection and climate change. During downturns in the economy, with such periods' employment uncertainties, the economy and jobs become of paramount importance to most Canadians. However, concern about the environment has remained high, as became evidenced very visibly in the political arena with the 1983 formation of the Green Party, nationally.

There have been changes in the values of corporate executives and employees. Those corporations that have recognized the need for changes have been making them in some or all aspects of their corporate structure, from committing to sound environment and resource management as one of their corporate goals or as part of their corporate philosophy or both, to making sincere efforts to consult with the public and public interest groups that might be affected by corporate activity. Corporations and industry organizations are working with the Canadian Standards Association (CSA) and the International Organization for Standardization (ISO) in a consultative process to establish standards for environmental management, pollution prevention, environmental labelling, etc.

Management and Governance

During much of Canadian history, the natural environment was considered to be both hostile and limitless, thereby affecting attitudes and hindering policies favouring its protection. Even with sustained public concern about environmental issues, and government commitments to sustainable development, renewable resource industries have yet to come effectively to grips with the fact that these resources are being harvested to extinction through short-sighted management practices that do not allow for populations to recover from the high rates of exploitation.

Although it is agreed that current practices will destroy the resource base for these industries, management systems that will ensure the economic benefits from these resources in perpetuity have yet to be implemented. The closures or reductions of fisheries on both coasts and the reductions in allowable annual cuts of forest resources reflect the failure to manage these resources on sustainable development principles.

It has gradually become recognized that the mandates and resources of the established agencies responsible for environmental matters have not been sufficient to prevent the continued deterioration of environmental quality and abuse of renewable resources. Substantial improvements were made in certain areas, but the persistent nature of some problems (soil erosion, water pollution, hazardous wastes, endangered species, acid rain) and the recognition of pressing new issues (climate change and ozone depletion) have led to the understanding that more fundamental problems have to be attacked.

Numerous federal and provincial government reports and efforts by non-governmental organizations (NGOs) and academics have identified the need for sound environment and resource management. Canada, the US and Mexico have signed the North American Free Trade Agreement (NAFTA), and a parallel environmental accord, which created the Commission for Environmental Cooperation. Montréal is the site of the headquarters for the secretariat that oversees the application of the provisions of the parallel accord.

Canada provided extensive support for the United Nations Report of the World Commission on Environment and Development (Brundtland Commission) and, for a time, followed one recommendation through the formation of the National Task Force on Environment and Economy and the subsequent establishment of "round tables" for discussions of problems and solutions for sustainable development at the federal and provincial levels. There were 14 round tables at the federal (1), provincial (10), and territorial (3) levels. Some regional and local governments were also using that mechanism for dispute avoidance and resolution and for policy development. Although most round tables have now been dissolved, the national round table remains an advisory committee to the federal government.

At the provincial level, most governments have started the development of more systematic conservation strategies. However, once again these strategies are not official policy: they are largely theoretical rather than practical documents, and they do not have timetables for implementation.

Agencies and Organizations

It was the environment movement of the late 1960s that led to the formation of government agencies and departments responsible for environmental matters. Alberta's Environment Conservation Authority (ECA) was the first such body in Canada (in existence from 1970 to 1995), formed through the Environment Conservation Act (1970). The federal Department of Environment (now Environment Canada) was established in 1971 through the Government Organization Act (1970).

In the early 1970s all provinces passed legislation establishing departments responsible for environmental matters, and most of them formed agencies responsible for public consultation. In the 1970s and 1980s, there were revisions and amendments, which, with a few exceptions, strengthened the legislation and regulations protecting the environment. The Canadian Environmental Network, Nature Canada, Canadian Wildlife Federation, Canadian Arctic Resources Committee and Canadian Environmental Law Association are good sources of information in their respective areas. Several industry organizations deal explicitly with environmental issues or have significant environmental components to their organizations. Some of the latter include the Canadian Association of Petroleum Producers (CAPP), Coal Association of Canada, Forest Products Association of Canada and Chemical Industry Association of Canada.

During the 1980s and 1990s, environmental organizations and other citizen groups demanded to be more directly and meaningfully involved in decisions related to the environment. Additionally, Indigenous peoples have gained recognition of their Aboriginal rights and have become important players in environmental management across many sectors and areas previously considered to be under federal or provincial jurisdiction. These demands and forms of recognition have led to a range of opportunities for environmental governance, which was not previously conceived. Federal and provincial governments are now only one set of players in a field that includes Indigenous peoples, private companies and individuals, municipalities, and civil society organizations. Environmental protection may be undertaken through a range of instruments that fall outside of government policies, legislation and programs. These may include agreements or contracts between parties, habitat protection on private lands, and co-management arrangements, to name a few. Government is no longer the sole caretaker of the environment, and the proliferation of other initiatives is a testament to peoples' ingenuity and commitment to environmental protection.

International Co-operation

Canada has been involved in numerous international efforts to deal with environmental problems. Canadians played significant roles at the 1972 United Nations Conference on the Human Environment in Stockholm, Sweden and the 1992 United Nations Conference on Environment and Development in Rio de Janeiro, Brazil. Canadian Maurice Strong was the secretary general of the 1992 conference. Canada has hosted major international conferences, notably the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer, and the first major conference on climate change, which was held in Toronto in 1988 (Our Changing Atmosphere: Implications for Global Security).

Canada has signed and ratified a large number of multilateral international agreements addressing a range of environmental and conservation problems: air pollution (eg, acid rain and climate change), biological diversity (eg, endangered species), chemicals (eg, persistent organic pollutants), ocean pollution (eg, dumping of wastes) and hazardous wastes (eg, the transboundary movement of these wastes). It also has bilateral agreements with the United States on a range of issues including water (eg, supply and quality), air quality, wildlife management (eg, migratory birds and the porcupine caribou herd) and hazardous wastes. There are also bilateral agreements with other countries, principally for environmental cooperation and information or technology exchanges (eg, with China and Egypt).

Since the 1990s, however, Canada has become a laggard in international environmental protection, particularly on the issue of climate change. While a signatory to the Kyoto Protocol in 1997, Canada will fail to meet its commitments, mainly due to inaction.

In the wake of the failure of the federal government to take a leadership role, other jurisdictions in Canada are making changes. The city of Toronto introduced bold new measures to reduce greenhouse gas emissions there. In 2008, British Columbia became the first jurisdiction in North America to introduce a consumer-based carbon tax to shift consumer preferences away from carbon-emitting activities and products. Ontario has also made renewed commitments to reducing greenhouse gas emissions.

Internationally, then, Canada's leadership role on environmental issues has diminished. However, efforts by other jurisdictions suggest that international leadership may come from outside the federal government in contemporary debates about the environment.