Calculating emissions intensity across the economy

New data show the most emissions-intensive sectors in Canada across Scope 1, 2, and 3 emissions.

At 440 Megatonnes, we’ve been tracking Canada’s climate progress through our Canadian Emissions Intensity Database, which helps businesses, governments and households estimate their emissions footprint.

Since we launched in November 2022, new data have become available.

The database provides emissions intensities for all the scope emissions in more than 60 economic sectors and 51 final demand expenditure categories and exports. This includes emissions from direct combustion (Scope 1), purchases of electricity and heat (Scope 2), and across supply chains (Scope 3 upstream).

Newly available data includes the federal government’s official National Inventory Report for 2021 greenhouse gas emissions. In addition, we’ve updated economic data points based on GDP from Statistics Canada for that year.

With new data in hand, we can compare progress across sectors and categories. And we can provide a more up-to-date tool for those using the database.

Canada’s top emissions-intensive sectors

Here we’ve broken down the top five most emissions intensive sectors in 2021 and how they compare to the previous year’s data.

In 2021, animal production and aquaculture was the most emissions intensive sector, followed by water, sewage and other systems, iron and steel mills and ferro-alloy manufacturing, and so forth.

In most cases, emissions for each sector were dominated by Scope 1 emissions—with the obvious exception being the petroleum and coal manufacturing sector. Some sectors saw greater year-on-year declines in emissions intensity, including petroleum and coal manufacturing, animal production and aquaculture, and iron and steel mills and ferro-alloy manufacturing.

Caveats to consider about emissions intensity

A couple points are worth mentioning before diving further into the data.

First, we’re considering the emissions intensities of each sector, which is different from total emissions. The data shows which sectors, pound for pound, emit the most greenhouse gases per unit of economic value, as expressed by GDP output.

This can be useful, not only to estimate an organization’s Scope 3 emissions footprint, if it isn't otherwise calculated from supply chain data. But it’s also useful to get a sense of the potential trade-offs when reducing emissions in different sectors through policy. Those sectors with high emissions intensity generate the smallest amount of economic wealth (GDP) per tonne of carbon emissions, and vice versa.

The second point is that our denominator—GDP, in this case—can change year to year based on whether commodity prices or profit margins change. That means a change in emissions intensity expressed in this way may not reflect an actual improvement in greenhouse gases emitted per unit of physical production—of tonnes of steel or barrels of oil, for example.

Physical units for emissions intensity are always a better measure to understand a sector’s progress to decarbonization, but this data can be difficult to come by. That said, tracking emissions by GDP is still a useful way to estimate emissions intensity and can provide a single metric against which all economic sectors can be compared against.

A deeper dive into the data

With that in mind, consider the steep declines in emissions intensity for petroleum and coal manufacturing in 2021, at nearly 25 per cent.

At first glance that seems like a good news story for climate progress. However, the bulk of that drop was driven by a decline in GDP that year (-32 per cent), and only modest declines in total emissions (-2 per cent).

Similarly, animal production and aquaculture saw a 15 per cent decline in emissions intensity, driven largely by a drop in GDP (-18 per cent), not a change in emissions.

It's also useful to consider the scale of these sectors relative to one another. Figure 2 shows the size of each sector in terms of GDP on the x-axis and the size of total Scope 1, 2 and 3 emissions on the y-axis. The total emission intensities are indicated by the bubble sizes.

You can see the rank order of each sector changes when considering total emissions and GDP contributions. Petroleum and coal manufacturing are far ahead of the pack on both metrics, but place fourth on emissions intensity. Likewise, water, sewage and other systems have the second highest emission intensity, but are the smallest of all sectors when it comes to total emissions and GDP. Animal production and aquaculture, the most emissions-intensive sector of the five, is still near the top when it comes to total greenhouse gas emissions and GDP contributions.

Decreasing emission intensity with clean tech

Each of these sectors have potential solutions to reduce emissions intensity in line with a net zero world.

Wastewater treatment plants can capture biogas and repurpose it to replace fossil fuels. The cement sector is piloting a number of ways to cut emissions, including through new applications of carbon capture and storage (see here, here, here and here). Clinker substitution with renewable resources is another potential route. And government and the steel industry have made big investments in emissions-cutting technologies that will move away from coal-based blast furnaces.

Most of the emissions from animal production and aquaculture come from methane released through the digestive process of livestock and manure management. Substituting and adjusting livestock feed can reduce these emissions–for example, by moving from corn to barley, adding seaweed or other food additives, or switching to high-quality forages like alfalfa.

While the primary goal of the emissions intensity database is to help estimate emission footprints, it can also provide new perspectives on progress across all sectors of Canada’s economy on the road to net zero.

Seton Stiebert is an advisor to 440 Megatonnes and the Principal of Stiebert Consulting.

Measuring the carbon footprint of plastics

What we know and don’t know about emissions from plastics in Canada.

Monday, June 5th marked the fiftieth anniversary of World Environment Day. This year, to celebrate a half century of the global awareness campaign, the United Nations is focussing on tackling plastic pollution. When we think of plastic pollution, we often think of waste littering our oceans or toxic chemicals and microplastics damaging our health. However, the carbon pollution of plastics is often overlooked.

Throughout their lifecycle, plastics have a significant carbon footprint—from the extraction of feedstocks all the way to their waste (mis)management. Yet understanding, and reducing, the lifecycle emissions of plastics in Canada is complicated. In this week’s Insight, we break down what we know, and don’t know, about the carbon footprint of plastics in Canada.

From cradle to grave: determining the lifecycle emissions from plastics

Plastics have become an ubiquitous part of our daily lives, largely because they are durable, versatile, lightweight, and cheap. They provide packaging that reduces food waste, they make up component parts of myriad innovative technologies and consumer products, they’re used to build cars, buses and trains, among countless other applications.

At the same time, plastics are a growing source of carbon emissions. Emissions are emitted at every stage of the plastics lifecycle—from the extraction and transportation of the fossil fuels used as feedstocks, to the production of the plastics themselves, to the management of plastic waste, and finally to the ongoing emissions impacts of plastics as they degrade in the environment.

The OECD estimates that the lifecycle emissions of plastics accounted for 3.4 per cent of global carbon emissions in 2019. Almost 90 per cent of global plastic emissions occur during the conversion process from fossil fuels and the production of plastics themselves, whereas the remaining 10 per cent occur at end-of-life. The OECD projects that, absent ambitious policy action, emissions could more than double by 2060 as plastic consumption grows, including in Canada.

While research in other countries, including the US, has tried to pinpoint the lifecycle emissions from plastics, Canada’s data is piecemeal, making it difficult to understand the full extent of the plastic industry’s contribution to national emissions.

What we know about emissions from plastics

The short answer: not enough. We have very limited publicly-available data about the lifecycle emissions of plastics in Canada. The best available data is for direct emissions from plastic product production, which are, on their own, very small.

In 2020, plastic product manufacturing in Canada was responsible for 703kt CO2e—or only 0.1 per cent of Canada’s total emissions in that year, a figure that has remained relatively stable over the last decade (Figure 1). If we only looked at the emissions from plastic production in Canada, we’d think emissions from the sector were negligible.

What we don’t know

Critically, the data we have captures only a slice of the total lifecycle of plastics. This “plastic production” category only includes the manufacturing (also known as conversion) of intermediate and final products from new or recycled plastic resins—products like plastic packaging, bottles, and pipes. This figure does not include emissions from the manufacturing of chemicals and resins that are then used in plastic production. According to a 2019 study on the global carbon footprint of plastics, the conversion stage generated approximately 30 per cent of total lifecycle emissions whereas the resin production stage generated 61 per cent.

Another major source of carbon emissions is the extraction and transportation of the fossil fuels feedstocks themselves. We know virgin resin accounts for the vast majority of resins used by plastic producers in Canada, and that the virgin plastic production is dependent primarily on oil or natural gas as feedstocks. The emissions from extracting and transporting natural gas and oil for plastics production is difficult to capture, but an important component of the industry’s emissions.

Finally, the emissions from feedstock extraction and transportation, as well as plastic production, could be significantly reduced if plastics were reused or recycled. Unfortunately, very little plastic is recycled in Canada. In 2019, only six per cent of plastic waste was recycled, 82 per cent was landfilled, seven per cent was mismanaged or uncollected litter, and four per cent was incinerated. While the recycling process itself uses energy and generates emissions, it reduces the need for new virgin feedstocks and keeps plastic waste out of landfills and incinerators, which are both sources of harmful emissions.

What to do about plastics emissions?

There are a number of approaches that governments in Canada can take (and are taking) to reduce the lifecycle emissions of plastics. Examples include banning single-use plastics, creating economic incentives to recycle, improving recycled content standards and labeling, investing in innovative, circular plastic technologies, using renewable energy for production processes,, and implementing extended producer responsibility programs. Beyond actions at home, Canada is also engaging in international efforts, including driving forward the development of a global treaty on plastic pollution.

Ultimately, however, what gets measured gets managed. More data, transparency, and accountability is needed to understand, and reduce, the lifecycle emissions of plastics in Canada. Reporting emissions data through the proposed federal plastics registry—for which draft regulations are due by the end of 2023—could be one way to improve what we know about plastic emissions in Canada.

Anna Kanduth was the Director of 440 Megatonnes at the Canadian Climate Institute.

Taking a bite out of food waste reduces emissions and saves households money

Embodied in Canadian-sourced food consumption and disposal are 58 megatonnes of carbon emissions annually. Addressing food waste can reduce those emissions by more than six megatonnes, and also reduce household costs.

What’s new?

There are 58 megatonnes of carbon emissions embodied in Canadian-sourced food purchases made by households (48.7 megatonnes) and in restaurants and food services (9.6 megatonnes). To put this into perspective, carbon emissions embodied in domestically sourced food purchases of all types are about equal to the combined emissions from Canada’s petroleum refining, cement and concrete, iron and steel, and chemical sectors.

As Canada drives to net zero, the emissions from Canadian-sourced food will need to be managed. A good place to start is reducing the substantial amount of food waste produced by households, restaurants, and food services. This could cut more than six megatonnes of emissions, lower household costs, and reduce water pollution and biodiversity loss.

Emissions from food waste are not just scraps

In 2020, food waste discarded with municipal solid waste across Canada was about 6.4 million tonnes or roughly 20 per cent of all food consumed, whether at home or purchased elsewhere. Of this discarded food, about 40 per cent could have been consumed while the rest is unavoidable loss in the form of table and kitchen scraps (Van Bemmel and Parizeau 2020). This avoidable food waste costs an eye-popping $12.8 billion annually. The economic cost also has an emissions cost, with two major sources of embodied emissions in avoidable food waste:

Emissions from the production and transportation of food, or Scope 3 emissions, are embodied in the food we consume. To estimate the avoidable emissions embodied in food waste, we need to calculate the quantity of avoidable food and the carbon intensity of that wasted food. We estimate the quantity of avoidable food waste for a family of four to be 326 kg per year, assuming 40 per cent of all food destined for landfills is avoidable. This avoidable waste represents a cost of $940 for a family of four. Using the 440 Megatonnes Canadian Carbon Intensity Database, and adjusting the carbon intensity for household food downward 25 per cent to avoid double counting emissions in supply chains, we estimate the Scope 3 emissions in avoidable food waste to be 470 kgCO2e per family per year.
Food waste that ends up in landfills creates greenhouse gas emissions in the form of methane. We use the Canadian Carbon Intensity Database to trace upstream emissions and the reported National Inventory Report emissions associated with solid waste disposal to calculate food disposal emissions. We estimate landfill emissions from household food waste to be 172 kgCO2e per person per year. If 40 per cent of food waste is avoidable, the embodied emissions of that waste are equal to 276 kgCO2e per family of four.

The total embodied emissions from all food waste for a family of four are 746 kgCO2e per year. Across all people in Canada, the total emissions from avoidable food waste is upwards of six megatonnes per year.

Governments need to tackle food waste and more

As food waste emissions are so high, they should be a priority for all orders of governments as they consider how to reduce emissions to 440 megatonnes by 2030 and net zero beyond. When other environmental benefits are factored in, such as biodiversity loss and water pollution, as well as the potential cost savings for households, the policy case to move on food waste becomes supercharged.

Although addressing household food waste is a good place to start in reducing emissions from Canadian-sourced food, there is still more to be done. For example, strengthening landfill methane regulations and providing capital to cash strapped municipalities to invest in waste-to-energy projects would go a long way to reduce end-of-life disposal costs from all food waste. In addition, to create incentives for addressing upstream emissions in food production, the fuel charge exemption for on-farm liquid fuel should end. Stay tuned for our upcoming insights on how Canada can take a bigger bite out of the emissions being produced by Canadian-sourced food.

Seton Stiebert is an advisor to 440 Megatonnes and the Principal of Stiebert Consulting. Dave Sawyer is the Principal Economist for the Canadian Climate Institute.