Infographic: What is a tonne of greenhouse gas emissions?

Climate change is the result of an overabundance of greenhouse gas (GHG) emissions in the atmosphere. The government of Canada has pledged to reduce national emissions by 30% from 2005 levels by 2030 – that is, to 524 megatons (Mt) of CO₂e emissions annually by 2030 compared to 732 Mt of CO₂e emissions in 2014.

Unfortunately, Canada hasn’t been reaching this goal. Our levels in 2005 were 732 Mt per year, meaning we had to reduce our emissions by 208 Mt per year. With only 6 years left to complete this goal, we’re not even close. By 2021, we were at levels of 670 Mt, which is only a decrease of 62 Mt, less than a third of what we need to reach our goal. We have much further to go, but it’s hard to do that when we don’t know what a megaton of GHG emissions actually means.

Understanding GHG emissions can be challenging. We cannot actually see them accumulate. And they come from a variety of sources. It doesn’t help either that we usually talk about these emissions in big units, which are hard to wrap our heads around. One megaton is a million tonnes.

So, to make it easier to understand, we can ask: what Canadian sources are equivalent to one tonne of GHGs? How does it translate to the real world, and how do these sources contribute to overall emissions?

One tonne of greenhouse gas emissions is equal to:

Heating a home for 4 months* 

By far, the single biggest source of emissions in Canadian households is space heating. It accounts for 63% of all household energy use. Because of cold Canadian winters, households use space heating systems that run on natural gas or heating oil for a good portion of the year. The high demand for heat means a single Canadian household will produce three tonnes of GHG emissions in a year from space heating alone. Canadian residential space heating accounts for 39 Mt of CO₂e emissions in a year, mostly over the winter months.

7 months powering a home

In Canada, households rely heavily on electricity. One of the biggest single electricity users is water heating systems which account for approximately 50% of an average Canadian’s household electricity. It takes only 14 months to reach one tonne of GHG emissions from powering just the water heating system of one house. Big household appliances, like refrigerators and clothes washers, use almost as much. Entertainment and home office electronics are often hidden from source-tracked use estimates because it comes from many smaller sources. Yet they use up to 20% of Canadians’ household electricity and collectively contribute 4.4 Mt of CO₂e emissions in a single year.

A year’s trash from 1 household

Compared to other countries with similar levels of disposable household income and urbanization, Canada has one of the highest levels of municipal waste production per capita.  This is the result of two significant factors: the increase in the overall waste Canadians make and the lack of comprehensive municipal waste diversion programs. Organics waste is one of the biggest contributors to municipal waste GHG emissions, especially when sent to landfills. About 35% of Canadian waste, measuring up to 10 Mt of CO₂e emissions annually, comes from food waste alone.

Driving 4500 km

Transportation is the second biggest GHG contributor in Canada. Within the sector, 53% of emissions are produced by personal vehicles. 4500 km is roughly the distance between Toronto and Vancouver or 40 hours of driving.  However, in 2012 the Pembina Institute estimated that Canadians living in metro or suburban areas (the majority) commute an average of 45km a day for work. At that rate, Canadian drivers produce one tonne of GHG emissions from just four and a half months of commuting. Personal vehicles driven in Canada contribute a yearly total of about 70 Mt of CO₂e emissions.

Raising a cow for 6 months

Cows produce an exceptionally high level of GHG emissions. Canadians also consume more beef than almost any other type of animal protein. This means cows are a big part of Canadians’ GHG footprint.

GHG emissions associated with beef are four times those associated with chicken, and 18 times higher than for beans and lentils. Cheese production contributes double the emissions of chicken and 9 times the emissions of beans and lentils. The emissions equivalent of raising a cow for 6 months is enough to produce beef and cheese to satisfy the average consumption of one Canadian for a year. The total emissions of cattle raising in Canada contributes 24 Mt of CO₂e emissions in a year.

Manufacturing 46 bags of cement  

Cement is the binding ingredient of concrete. Concrete is used in a multitude of ways in urban and industrial development. 46 bags of cement is enough to construct about 40 metres (or 125 feet) of concrete city sidewalk. The average concrete and steel commercial building, the predominant choice for most mid- and high-rise buildings constructed in the last century, uses 200 times that much cement. In Canada, the energy-intensive cement industry contributes 10 Mt of CO₂e emissions annually.

Extracting 15 barrels of oil

Extracting oil from the ground produces emissions even before it is refined, transported, and used. The Canadian oil and gas sector produces 1.6 billion barrels of oil a year which is estimated to produce 104 Mt of CO₂e emissions at the point of extraction. These emissions are, in many ways, unaccounted-for lifecycle emissions for any oil-based energy or products (which includes many daily-use household items), essentially doubling actual emissions for things like gasoline used in a car.

Take Action

These are some examples of sources of one tonne of GHGs and how they fit into the Canadian context. Clearly, significant emission reductions require changes in industrial practices and, by extension, increased government action. Still, with a better understanding of Canada’s GHG emissions and how Canadians’ lifestyles contribute, individuals and households should find it easier to translate that into action to reduce the impact. And, if every Canadian took action the overall Canadian GHG footprint could be markedly reduced.

For suggestions, read 9 ways to reduce your GHG footprint.

Infographic by Miriam Mahaffy

*note: statistics are Canadian averages; % and Mt vary between provinces due to differences in energy sources, use distribution of sources, and regional temperatures for both electricity and heating.