Climate change is greatly impacting Canada's environment and landscapes. Extreme weather has become more frequent and severe because of the continued release of greenhouse gases into the atmosphere. The number of climate change–related events, such as the 2021 British Columbia Floods and an increasing number of forest fires, has become an increasing concern over time. Canada's annual average temperature over land warmed by between 1948 and 2016. The rate of warming is highest in Canada's north, the Prairies, and northern British Columbia. The country's precipitation has increased in recent years and wildfires expanded from seasonal events to year-round threats.
, Canada was the world's 11th highest emitter of carbon dioxide (CO2) and as of 2021 the 7th highest emitter of greenhouse gases. Canada has a long history of producing industrial emissions going back to the late 19th century. In 2022 transport, oil and gas extraction, and fugitive emissions together emitted 82% of the country's total emissions. From 1990 to 2022, GHG emissions from conventional oil production increased by 24%, those from multi-stage fracturing techniques increased by 56%, and emissions from oil sands production increased by 467%. This has led to criticism against Canada for committing to reducing greenhouse emissions while supporting its oil and gas industry.
Canada committed to reducing its greenhouse gas (GHG) emissions by 30% below 2005 levels by 2030 under the Paris Agreement. In July 2021, Canada enhanced the Paris Agreement plans with a new goal of reducing emissions by 40–45% below 2005 levels by 2030, enacting the Canadian Net-Zero Emissions Accountability Act. In 2019, the House of Commons voted to declare a national climate emergency in Canada. Several climate change mitigation policies have been implemented in the country, such as carbon pricing, emissions trading and climate change funding programs.
Greenhouse gas emissions
Climate change is the result of greenhouse gas emissions, which are produced by human activity. Canada was the world's 7th largest greenhouse gas emitter in terms of GHG Inventory data, as of 2021. In 2020, Canada emitted a total of 678 million tons of carbon dioxide equivalent (Mt COeq) into the atmosphere. This represents a decrease from 1.8% of global emissions (730 Mt COeq) in 2005 to 1.5% in 2020, but still an increase from 602 Mt COeq in 1990. In 2022, Canada’s GHG emissions were 708 Mteq, still below pre-pandemic (2019) emissions, but an increase of 9.3 Mt (1.3%) compared to 2021. The Canadian Climate Institute reported a net drop of about 1% in emissions during 2023, largely due to the electricity and housing sectors. In contrast, emissions from oil, gas and transportation continued to rise.
The WRI's Climate Analysis Indicators Tool estimates that, between 1950 and 2000, Canada had the highest greenhouse gas emissions per capita of any first world countries.CAIT 4.0 database (registration required) In 2020, of all the G20 countries, Canada was second only to Saudi Arabia for greenhouse gas emissions per capita.
Canada has one of the heaviest climate debts in the world, with a very long history of producing industrial greenhouse gas emissions. Canada is the 10th heaviest cumulative emitter as assessed by model-based land-use mitigation measures, with 2.6% of cumulative emissions. Canada's 65.5 billion tonnes of carbon come roughly equally from use of fossil fuels and from deforestation and land use.
Energy consumption Electricity consumption in Canada in 2017 accounted for 74 carbon dioxide equivalent Mt COeq, or 10% of the country's emissions. This sector's climate footprint significantly reduced in recent decades due to the closure of many coal-fired power stations. As of 2017, 81% of Canada's electricity is produced by non-emitting energy sources, such as hydro, nuclear, solar or wind power.
Fossil fuels provide 19% of Canadian electric power, about half as coal (9% of the total) and the remainder a mix of natural gas and oil. Only five provinces use coal for electricity generation. Alberta, Saskatchewan, and Nova Scotia rely on coal for nearly half their generation while other provinces and territories use little or none. Alberta and Saskatchewan also use a substantial amount of natural gas. Remote communities including all of Nunavut and much of the Northwest Territories produce most of their electricity from diesel generators, at high economic and environmental cost. The federal government has set up initiatives to reduce dependence on diesel-fired electricity.
Transportation Canada is a large country with a low population density, so transportation – often in cold weather when fuel efficiency drops – is a big part of the economy. In 2017, 24% of Canada's greenhouse gases (GHG)s came from trucks, trains, airplanes and cars.
The vast majority of Canadian emissions from transportation come from road transportation, accounting for 144 Mt COeq, or 20% of total emissions. These originate for individual cars, but also from long-haul trucks, which are used to transport most goods across the country. In 2018, the Canadian truck industry delivered 63.7 million shipments. In 2019, Canadian factories produced 1.4 million new trucks, more than triple the Canadian car production.
The Canadian domestic aviation industry, represented largely by the country's two main airlines (Air Canada and WestJet), produced 7.1 Mt COeq in 2017 and account for 1% of Canada's total greenhouse gas emission.
Fossil fuel production
The most pollutant industry in terms of GHG emissions in Canada is the oil and gas sector. This industry produces 195 Mt COeq every year, which is 27% of the national total. Driven by the high emissions required for the exploitation of the tar sands in Alberta, greenhouse gas emissions from this sector increased by 84% from 1990 to 2017.
Industrial emissions In 2017, Canadian heavy industry emitted 73 Mt COeq, or 10% of Canada's total greenhouse gas emission. This represents a 25% drop in emissions in this category since 1990. This data is consistent with the rapid decline of manufacturing in Canada.
Deforestation Canada's deforestation rate is one of the lowest in the world, at 0.02 percent per year. This rate of deforestation has been reducing every year since 1985.
According to Environment and Climate Change Canada (ECCC), "Harvested wood products" in Canada account for 130 Mt COeq of greenhouse gas emissions. This would represent 18% of the country's emissions in 2017, but ECCC exclude this number from its national total. Also excluded from the total is ECCC's calculation that Canada's forests reduce greenhouse gas emissions by 150 Mt COeq. Before 2015, ECCC used to calculate a 160 Mt COeq reduction from its forest, a sign of their slow but continued deterioration.
Impacts on the natural environment In recent decades, Canada has experienced increased average temperatures, increased precipitation, and more extreme weather events. These trends are expected to continue over the next century. ECCC determined it was extremely likely that these changes were the result of increased greenhouse gas emissions driven by human activity.
Temperature and weather changes
Annual average temperatures in Canada increased by 1.7 °C between 1948 and 2016. These weather changes have not been uniform across regions. British Columbia, the Prairie provinces and Northern Canada experienced warming the most, with an annual increase of 2.3 °C for northern Canada. Meanwhile, some Maritime areas of southeast Canada experienced average warming of less than 1 °C during the same period. In addition, these trends were not uniform across the seasons. Average winter temperatures rose by 3.3 °C between 1948 and 2016 while average summer temperature only rose by 1.5 °C.
According to Environment and Climate Change Canada "warming over the 20th century is indisputable and largely due to human activities" adding "Canada's rate of warming is about twice the global rate: a 2° C increase globally means a 3 to 4 °C increase for Canada".
ECCC lists impacts of climate change consistent with global changes. Temperature-related changes include longer growing season, more heatwaves and fewer cold spells, thawing permafrost, earlier river ice break-up, earlier spring runoff, and earlier budding of trees. Meteorological changes include an increase in precipitation and more snowfall in northwest Arctic.
Precipitation ECCC summarized annual precipitation changes to support biodiversity assessments by the Canadian Council of Resource Ministers. Evaluating records up to 2007 they observed: "Precipitation has generally increased over Canada since 1950 with the majority of stations with significant trends showing increases. The increasing trend is most coherent over northern Canada where many stations show significant increases. There is not much evidence of clear regional patterns in stations showing significant changes in seasonal precipitation except for significant decreases which tend to be concentrated in the winter season over southwestern and southeastern Canada. While the previous sentence might be technically correct in part, all seasons show increased precipitation in Canada, especially in the Winter, Spring, and Fall months. Also, increasing precipitation over the Arctic appears to be occurring in all seasons except summer."
ECCC climate specialists have assessed trends in short-duration rainfall patterns using Engineering Climate Datasets: "Short-duration (5 minutes to 24 hours) rainfall extremes are important for a number of purposes, including engineering infrastructure design, because they represent the different meteorological scales of extreme rainfall events." A "general lack of a detectable trend signal", meaning no overall change in extreme, short-duration rainfall patterns was observed in the single station analysis. In relation to design criteria used for traditional water management and urban drainage design practice (e.g., Intensity-Duration-Frequency (IDF) statistics), the evaluation "shows that fewer than 5.6% and 3.4% of the stations have significant increasing and decreasing trends, respectively, in extreme annual maximum single location observation amounts." On a regional basis, southwest and the east (Newfoundland) coastal regions generally showed significant increasing regional trends for 1- and 2-hour extreme rainfall durations. Decreasing regional trends for 5 to 15 minute rainfall amounts were observed in the St. Lawrence region of southern Quebec and in the Atlantic provinces.
Extreme weather events
The extreme weather events of greatest concern in Canada include heavy rain and snow falls, heat waves, and drought. They are linked to flooding and landslides, water shortages, forest fires, reduced air quality, as well as costs related to damage to property and infrastructure, business disruptions, and increased illness and mortality. Heat waves, including those in the summer of 2009, 2012, and 2021, are associated with increases in heat stroke and respiratory illness.
According to a 2015 study, the number of fire spread days in Canada, as a result of climate change, would increase by 35-400% by 2050, with coastal and temperate forests being most affected areas in terms of proportion. Canada is already seeing these predictions come to fruition, as the 2023 Canadian wildfire season burned over 15 million hectares due to the extreme hot and dry weathers. This is more than seven times the 40-year average.
Sea level rise