Greenhouse gas emissions: drivers and impacts

Most greenhouse gases (GHGs) can be emitted by both natural processes and human activities. According to the Intergovernmental Panel on Climate Change, human-driven releases of GHG emissions disrupt the natural processes occurring in the atmosphere and are very likely to be the dominant cause of the observed warming that has occurred since the mid-20th century. Globally, almost 80% of GHG emissions from human sources come from the burning of fossil fuels and industrial processes. Specific activities include: driving vehicles, electricity production, heating and cooling of buildings, operation of appliances and equipment, production and transportation of goods, and provision of services and transportation for communities. In 2021, about 28% of Canada's total GHG emissions came from the oil and gas sector, 22% from transport, 13% from buildings and 11% from the heavy industry sector.

Global GHG emissions grew by 23% between 2005 and 2019,Footnote 1  with the bulk of the growth occurring in developing countries. During this period, Canada's share of total global GHG emissions remained at less than 2%, although it is one of the highest per capita emitters. In 2019, Canada’s GHG emissions per capita were 19.6 megatonnes of carbon dioxide equivalent (Mt CO2 eq),Footnote 2  compared to 6.3 Mt CO2 eq globally.

Different GHGs have different global warming potential and lifespans in the atmosphere. Short-lived climate pollutants, such as methane (CH4) and hydrofluorocarbons (HFCs), are GHGs known to be very potent with relatively short lifespans. As such, emission reductions of short-lived climate pollutants can reduce atmospheric levels of these GHGs at a much quicker pace than comparable reductions from longer-lived GHGs. Therefore, immediate action to reduce these particular GHGs can have significant benefits for curbing near-term climate warming.

In 2015, Canada and 194 other countries reached the Paris Agreement which aims to limit the global average temperature rise to well below 2 degrees Celsius and pursue efforts to limit the increase to 1.5 degrees Celsius. To achieve this long-term goal, the Paris Agreement requires countries to increase their ambition every 5 years. In 2021, Canada enhanced its initial target and commited to reducing its GHG emissions by 40 to 45% below 2005 levels by 2030. In addition, Canada has committed to reaching net-zero emissions by 2050 and adopted the Canadian Net‑Zero Emissions Accountability Act in June 2021 to enshrine this commitment in federal legislation. By doing so, it will help to limit global average temperature rise to well below 2 degrees Celsius.  

Key drivers of greenhouse gas emissions

A wide variety of factors have an influence on the level of GHG emissions in Canada. These include Canada's physical geography, demographic changes in its population and economic growth.

Canada has a highly variable climate. This contributes to relatively higher energy use for space heating and cooling in buildings, compared with other industrialized countries. While vast, Canada is also sparsely populated, which leads to longer travel times and higher demand for transportation than in smaller and/or more densely populated countries. In addition, Canada had the fastest population growth and its economy showed the second fastest growth among the G7 countries from 2005 to 2021.

Despite these challenges, over the past 2 decades, Canada has seen a decoupling between growth of the economy and GHG emissions. Over this period, technological improvements and regulations have been adopted and implemented in various economic sectors, particularly for electricity generation, to help reduce emissions.

Other important factors influencing GHG emissions include the adoption of more efficient practices and equipment by consumers and industry as their knowledge about their choices and the impacts of those choices on the environment is improving. Examples include how people commute to work, where businesses decide to locate their manufacturing facilities and the decisions made to increase the efficiency of industrial processes or to manufacture more energy-efficient products.

Key impacts of greenhouse gas emissions

The release of GHGs and their increasing concentration in the atmosphere are already having an impact on the environment, human health and the economy. These changes notably manifest in Canada's north, affecting many indigenous and remote communities. The impacts are expected to become more severe, unless united efforts to reduce emissions are undertaken.

Environmental impacts

  • Overall, average annual temperatures are expected to increase
  • Snow, sea ice and glacier coverage will decrease due to higher temperatures, resulting in rising sea levels and increased coastal flooding. Rising temperatures will also thaw permafrost in the Arctic
  • Future coastal-erosion rates will likely increase in most areas due to milder winters and smaller ice coverage
  • Overall precipitation levels are expected to increase across most of the country and during all seasons, except for parts of southern Canada where there are indications of an expected decrease in summer and fall precipitation
  • The increase in precipitation is expected to be combined with more frequent heavy precipitation events, resulting in higher risks of flooding
  • Heat waves are likely to increase in frequency and severity, resulting in higher risks of forest fires
  • Many wildlife species will have difficulty adapting to a warmer climate and will likely be subject to greater stress from diseases and invasive species

Human health impacts

  • Higher temperatures and more frequent and severe extreme weather events may increase the risk of deaths from dehydration and heat stroke, and of injuries from intense local weather changes
  • There may be a greater risk of respiratory and cardiovascular problems and certain types of cancers, as temperatures rise and exacerbate air pollution
  • The risk of water-, food-, vector- and rodent-borne diseases may increase
  • Mental health can be affected by concerns associated with climate change and its impacts  or by the traumas from short-term (extreme weather events) and long term climate-related hazards (drought, sea-level rise, thawing permafrost)
  • People living in Canada's northern communities, and vulnerable populations such as children and the elderly, are expected to be the most affected by the changes

Economic impacts

  • Agriculture, forestry, tourism and recreation may be affected by changing weather patterns
  • Human health impacts are expected to place additional economic stress on health and social support systems
  • Damage to infrastructure (for example, roads and bridges) caused by extreme weather events, thawing permafrost and rising sea levels is expected to increase, impacting local populations and resource development

Ways to reduce greenhouse gas emissions

Addressing climate change requires action from everyone across all nations. Governments, businesses and individuals need to take significant steps to reduce emissions by using resources more efficiently and adopting new and cleaner technologies.

Governments

In 2016, Canada released the first-ever national climate plan – the Pan-Canadian Framework on Clean Growth and Climate Change – jointly developed by the federal, provincial and territorial governments. The plan includes a pan-Canadian approach to pricing carbon pollution, and measures to achieve emissions reductions across all sectors of the economy. It also aims to drive innovation and growth; increase technology development and adoption to ensure Canadian businesses are competitive in the global low-carbon economy. The measures in the Pan-Canadian Framework sets in place Canada's foundation for reaching its 2030 and 2050 targets.

In December 2020, the Government of Canada released its strengthened climate plan, A Healthy Environment and a Healthy Economy, which builds on the measures included in the Pan-Canadian Framework. The plan contains 64 strengthened and new federal policies, programs and investments to cut pollution and build a stronger, cleaner, more resilient and inclusive economy. Also as part of the plan, the Government of Canada released Canada’s first National Adaptation Strategy in November 2022.

In March 2022, the Government of Canada published the 2030 Emissions Reduction Plan under the Canadian Net-Zero Emissions Accountability Act, which continues to build upon the actions outlined in Canada's previous climate plans. This plan is a roadmap that outlines a sector-by-sector measures and strategies  for Canada to reach its emissions reduction target of 40-45% below 2005 levels by 2030 and put in the place the building blocks to achieve net-zero emissions by 2050. The plan will be reviewed and updated in progress reports produced in 2023, 2025 and 2027. Additional targets will be developed in 5-year intervals for 2035 through to 2045, as well as associated plans through to 2050.

Implementing the Pan-Canadian Framework and the strengthened climate plan, and releasing a National Adaptation Strategy are key actions or milestones noted in the Federal Sustainable Development Strategy. The Strategy sets out the Government of Canada's sustainable development priorities, establishes goals and targets, and identifies actions to achieve them. The 2022-2026 Strategy, Canada's fifth, outlines the actions toward sustainability that the Government will take in collaboration with partners within Canada and internationally. As such, it supports the 2030 Agenda for Sustainable Development and its global sustainable development goals (SDGs).

To learn about the expected impact of GHG emission regulations developed by the government of Canada, consult the Regulatory Impact Analysis StatementFootnote 3  (also known as a RIAS) which accompanies each regulation. The RIAS outlines the reasons behind the development of a particular regulation, its objectives and its expected costs and benefits. The RIAS also includes details about consultations that were conducted and about how the government intends to track the performance of the regulation.

Businesses

Companies are increasingly integrating the need to reduce GHG emissions and carbon pricing considerations into their investment, planning, and operational decisions in order to improve their long-term resilience and competitiveness. Through their actions and investments, companies can also support the transition to a low-carbon economy. For example, nearly 40 Canadian companies contribute to the Carbon Pricing Leadership Coalition, a voluntary initiative that supports and encourages successful implementation of carbon pricing around the world.

Private sector capital and expertise will be needed to contribute to Canada’s climate objectives and create a climate-resilient economy. Supported by the recent launch of the Sustainable Finance Action Council, the Canadian financial sector is working towards integrating sustainable finance into standard industry practice. Sustainable finance refers to the incorporation of climate and environmental considerations throughout financial decision making. In turn, this enables the mobilization and alignment of private sector investments towards climate and environmental objectives.

Individuals

Individuals can reduce GHG emissions at home, at work and in everyday activities. We can make a difference by changing our behaviour and making lifestyle decisions that reduce emissions. For more information on how individual Canadians can help our environment, including by reducing GHG emissions, consult Things you can do to improve climate change and the environment on the Government of Canada's Climate change website.

Sources

Environment and Climate Change Canada (2016) Pan-Canadian Framework on Clean Growth and Climate Change.

Environment and Climate Change Canada (2019) Canada’s National Reports to the United Nations Framework Convention on Climate Change (2017).

Environment and Climate Change Canada (2020) A Healthy Environment and a Healthy Economy.

Environment and Climate Change Canada (2023) Canada's Eighth National Communication and Fifth Biennal Report.

Health Canada (2008) Human Health in a Changing Climate: A Canadian Assessment of Vulnerabilities and Adaptive Capacity.

Intergovernmental Panel on Climate Change (2022) Climate Change 2022: Impacts, Adaptation, and Vulnerability.

Intergovernmental Panel on Climate Change (2019) Special Report: Global Warning of 1.5°C.

International Monetary Fund (2023) World Economic Outlook (April 2023).

Natural Resources Canada (2008) From Impacts to Adaptation: Canada in a Changing Climate 2007.

Natural Resources Canada (2015) Canada in a Changing Climate: Sector Perspectives on Impacts and Adaptation.

Natural Resources Canada (2016) Canada's Marine Coasts in a Changing Climate.

World Resources Institute (2023) Climate Watch Country Historical Greenhouse Gas Emissions.

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