Where Do Canada’s Greenhouse Gas Emissions Come From?

Earth’s atmosphere is made up of many different gases, some of which are “greenhouse” gases. They are called that because they effectively act like a greenhouse or a layer of insulation for Earth: they trap heat and warm the planet.

For the past couple of hundred years, human activities (such as burning coal to generate electricity and fuelling our vehicles with gas and diesel) have been changing the atmosphere by adding a huge volume of greenhouse gases. This has caused the greenhouse effect to become stronger, and is making the planet warmer.

Canadians produced over 720 megatons (Mt) of greenhouse gases (GHGs) in 2015[1]. That’s a lot of gas: 1,587,600,000,000 pounds of it, to be precise, or as much 120,000 fully loaded freight trains[2].

In this post, we dig deeper into Canada’s GHG statistics, deciphering some of the jargon and making sense of the data.

Who are the biggest emitters?

The oil and gas industry is Canada’s leading GHG emitter. Emissions from the transportation sector are a close second.

Since GHG recordkeeping began in the 1990s, some economic sectors in Canada have managed to reduce their carbon footprints. Electricity generation, for example, has managed to cut emissions, as new technologies and an increase in renewables have drastically cut our reliance on coal.

Canada’s Greenhouse Gas Emissions by the Numbers

The graph above told us which sectors produce the most greenhouse gases. It very clearly shows that the oil and gas and the transportation sectors are the largest contributors to national GHG emissions. But these numbers can be further pulled apart to better show when and how these gases get released into the atmosphere.

(Click to enlarge)

328 Mt (45%) Burning Fuel to Generate Energy

By far the largest source of GHG emission in Canada comes from the combustion of fossil fuels to make energy, including heat and electricity. Mining, oil and gas, and manufacturing are collectively responsible for the largest slice of this pie, followed closely by houses, shops, schools and other private and public buildings. It is important to note that the total emission from the oil and gas sector cover multiple categories, meaning these numbers only tell part of the story.

Moving towards more power-smart building designs can help greatly reduce GHG emissions, including the adoption of more passive solar heating and cooling systems. At the household level, even small steps like choosing energy efficient light bulbs and installing a smart home-thermostat can add up to make a difference.

202 Mt (28%) Transportation

The movement of people and goods across Canada’s wide and diverse landscape is the second-leading source of GHGs. Here, cars and trucks—including personal vehicles and commercial vehicles—share the largest slice of the pie. Electric and hybrid vehicle technologies can help lower emissions, but an equally important step would be towards building more bike paths and designing better public transportation routes. The emissions that come from marine and aviation traffic may, at first blush, seem smaller than expected; however, it is important to note that the Government of Canada does not count the emissions released during international trips.

59 Mt (8.2%) Agriculture

In Canada, a lot of energy goes into growing food. Very large volumes of fuel and fertilizer are used to run farms, and both contribute to national GHG emissions. It is important to note that the actual manufacture of fertilizers is counted under “Industrial Processes and Product Use” and so the numbers here only represent the emissions that are released when fertilizer is applied to a field. Industrial scale livestock operations also produce large volumes of GHGs. However, an often-unappreciated source of GHGs comes from outdated and unsustainable soil management practices. Agricultural emissions can be significantly lowered by using zero-tillage methods and focussing on soil health regeneration. Similarly, there are many techniques farmers can use to lessen their reliance on fertilizers.

57 Mt (7.9%) Flaring, Unintentional Emission, and Leaks

The fourth largest source of GHG emission in Canada comes from so-called ‘fugitive emissions,’ or greenhouse gas emission that are released into the air as an unintentional by-product of industrial activities. This includes flaring, venting, leaks, and spills. Virtually all fugitive emissions are released by the oil and natural gas sector.

51 Mt (7.1 %) Industrial Processes and Product Use

Many of the products we use everyday have hidden GHG footprints. Take cement: the production of cement requires a lot of heat energy, but its GHG footprint gets doubled in size because of a chemical reaction that takes during concrete formation. Manufacturing nitrogen fertilizers also uses a surprisingly large amount of energy, and once applied to a field these fertilizers mix with the air to produce even more potent GHG emissions. A lot of chemicals and substances that are harmful to human health, including fire retardants, solvents, and acids, also have large GHG footprints. This means that as we reduce our GHG emissions, we also stand a good chance of improving our health. It is important to note that the emissions released to create products later imported into Canada are not counted here.

25 Mt (3.5%) Garbage and Wastewater

A surprising volume of GHGs come from landfills and wastewater treatment plants. When garbage breaks down deep within in a landfill it produces methane, a powerful greenhouse gas. Reducing waste is an obvious step towards reducing these emissions; however, employing new technologies like landfill-gas capture also help.

Some Good News

Here’s some food for thought: overall, total GHG emissions per GDP and per person have declined since the 1990’s, despite the fact that Canada’s economy and population have grown since then. This means that the steps we’ve taken to become more energy efficient and environmentally responsible have actually worked. We still have a long way to go before we will be on track to meet our emissions targets laid out during the 2015 Paris Negotiations; however, with a new national carbon pricing plan in the works, exciting new developments in renewable energy and electric vehicles, and a greater understanding and appreciation of climate change among the public, it seems like now is Canada’s moment to show the world what climate leadership can be.

Written by Ryan Smith

Illustration by Bradford Gyselman


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[1]                  Weights are displayed as Mt CO2e (Megatons of carbon dioxide equivalent), which takes into account the global warming potential of all greenhouse gases relative to carbon dioxide. Data source: https://www.ec.gc.ca/indicateurs-indicators/default.asp?lang=en&n=FBF8455E-1

[2]                  One megaton equals one million metric tons. One metric ton is 2,205 pounds. Here, we assumed that a fully loaded freight train weighs approximately 6,000 tons.