Mapping Canada’s path to net-zero greenhouse gas emissions by 2050

Scientists have shown that the world must keep its average temperature increase to 1.5 C to avoid the worst effects of climate heating.

Even at the present 1.1 C, the effects in Canada are severe: extreme heat in B.C. that killed 600 people, B.C. wildfires that destroyed Lytton, recent rainstorms, and landslides there, and the prairie drought that greatly reduced agricultural output and is driving up food prices.

The difference between 1.5 C and 2 C is enormous. For example, extreme heat will occur two-and-ahalf times more often at two degrees of warming than at 1.5.

Canada has promised to reduce greenhouse gas emissions 40 to 45 per cent by 2030, and to reach netzero (explained below) by 2050. Greenhouse gases (GHGs) are gases produced mostly by human activity.

They trap heat from the sun, warming the Earth. The main GHGs are CO2 (carbon dioxide), NH4 (methane, the main component in natural gas), and nitrous oxide (NO2). These have different strengths as GHGs, and each lasts a different amount of time. Scientists combine their effects into a single number called CO2e, or “carbon dioxide equivalent.”

The amount of CO2e has risen steadily with the burning of fossil fuels starting in about 1850.

“Net-zero” means extracting as much CO2 from the air as emitted every year, although the technology to do this does not yet exist. At net-zero, the world’s temperature will essentially stop changing but not decrease for centuries. How about “natural solutions” to remove the extra CO2, such as planting trees? These are not a substitute for reducing CO2 emissions, as all plants eventually die and release their carbon.

Fig. 1 shows the main sources of Canada’s carbon emissions since 1990. The dashed, white line show Canada’s current 2030 target. The total height of each bar gives Canada’s total emissions that year, and the coloured sections show the sources.

Canada’s emissions have risen 20 per cent since 1990. Under the Kyoto Protocol, ratified by Liberal PM, Jean Chrétien, in 2006, Canada promised to reduce emissions six per cent from 1990 levels between 2008 and 2012. Instead, emissions increased over 30 per cent in that time. Canada officially withdrew from Kyoto under Prime Minister Stephen Harper, in 2011.

We will consider only the 2019 bar at the right. The bottom maroon section represents the emissions from producing Canada’s fossil fuels, before any of them are even burned. This represents 26 per cent of Canada’s GHGs as labelled and is Canada’s single biggest source.

The blue bar represents transport — automobiles, trucks, planes, trains, and ships. This produces 24 per cent of Canada’s emissions, so along fossil-fuel production we’re already up to 50 per cent. We’ll discuss each contribution in turn.

Oil and gas production (26 per cent)

Trudeau has promised, “We’ll cap oil and gas sector emissions today and ensure they decrease tomorrow at a pace and scale needed to reach net-zero by 2050.” This includes five-year mandatory targets, leaving it to the industry to figure out how to do this, and requiring technology not yet develqo

ed. If the government enforces the targets, this will reduce these emissions to net-zero by 2050. However, a recent study in Nature Energy states that half the world’s fossil fuel deposits could become worthless by 2036, including Canada’s tarsands. Therefore, these emissions could reach net-zero before 2050.

Transportation (24 per cent)

This consists of on-road passenger vehicles (buses, cars, light trucks) at 45 per cent; on-road freight 37 per cent; rail four per cent; air five per cent; marine four per cent; and other five per cent. On-road passenger: Trudeau promises no fossil-fuel light-vehicle sales after 2035. Assuming an average lifetime of 10 years, most gas and diesel cars will be gone by about 2045. City buses will be electrified, and increased densification of city residences and stores will increase walking, cycling and transit use. On-road-freight and rail. Long-haul trucks will be powered by “green” hydrogen (from water using renewable energy) and biofuels (manufactured from plants). Short-haul trucks will be electric. Aviation: Some planes may be electric for short hops, such as Harbour Air in B.C. Large aircraft will use green hydrogen or biofuels w

Marine: Biofuels will be the primary power source for long distances. Electric ferries are already operating.

Buildings (13 per cent)

There are two categories, namely new and existing buildings. Canada adds one per cent of new buildings per year, so we need a net-zeroready building code quickly. “Netzero ready” means buildings are so energy efficient they can produce as much renewable energy on site as they use annually. Canada’s National Research Council (NRC) expects to release such a code soon, with all provinces adopting it by 2030. Heat pumps using low-carbon electricity provide heating at about one-quarter the cost of electric baseboards, which will soon make heat pumps cost-competitive with natural gas. Domestic water heaters and clothes dryers using heat pumps also greatly reduce electricity use. However, the combination of electrifying vehicles and buildings will require at least doubling Canada’s electrical production with non-polluting generation.

A harder job is to energy-retrofit existing houses using draft-proofing, more insulation, and low-loss windows. The upside will be the creation of thousands of good jobs. The NRC has a retrofit code under development. There is already a $5,000 federal incentive for retrofits, with $40,000 promised as an interest-free loan for “deep” energy retrofits targeting multiple aspects.

Electricity generation (nine per cent)

Eighteen per cent of Canada’s electricity is from burning fossil fuels, 60 per cent waterpower, 15 per cent nuclear, and seven per cent solar and wind. This is clean compared to most of the world. However, the mix varies by province, with B.C., Manitoba, Quebec, and Newfoundland using primarily hydro. Alberta and Saskatchewan rely on fossil fuae ls, although they have enormous potential for wind and solar energy, plus geothermal in Alberta. Ontario has some of the cleanest electricity in the world: 60 per cent nuclear (with low GHG emissions), 26 per cent hydro, nine per cent wind and solar, and three per cent natural gas. Unfortunately, Ontario is planning for a dramatic increase in its use of natural gas as it decommissions and refurbishes its nuclear plants.

But where does renewable electricity come from when the sun does not shine, and the wind does

CONTINUED FROM B10 not blow? For these periods, Canada must store energy. This can be done with giant batteries (as in Australia) or using the hydro capacity of neighbouring provinces to act as a giant battery, letting water accumulate when not needed and released when required. Nuclear energy provides an excellent baseline source but is much more expensive to build than solar or wind and requires a lead time of about 10 years. The government has promised funds to develop more nuclear electricity from small modular reactors which can be transported to where needed.

Heavy Industry (11 per cent)

Much of industry GHGs are from steel and cement production. Cement is now made by heating limestone to high temperatures using fossil fuels, with CO2 also released from the limestone. Options being developed to reduce these emissions include adding different materials such as ground-reclaimed concrete or capturing most of the CO2 from the flue gas. LaFarge Canada is a leader in this field, with its concrete having “30 to 100 per cent less emissions.”

To produce steel, iron ore must be heated to high temperatures. Every ton of steel produces on average 1.85 tons of carbon dioxide. Options are to use hydrogen or electric-arc furnaces, both using renewable electricity. A Swedish company recently delivered the world's first fossil fuel-free steel. Another option is to replace steel and concrete with “cross-laminated timber” in buildings, as in Vancouver’s 18-storey Brock Commons. Wood also has the advantage of sequestering the carbon stored in its fibres.

Agriculture (10 per cent)

Fertilizer is responsible for 44 per cent of these GHGs, mostly from N2O. Nitrogen-fixing cover crops such as clover reduce the need for fertilizer but are insufficient in themselves. This remains an unsolved problem.

Methane burps from cattle, sheep and goats account for 30 per cent of agricultural GHGs, and methane from manure adds another 10 per cent. Therefore, different foods cause very different emissions. Pounds of CO2e emitted per pound of food eaten is as follows: Beef (60), mutton (24), cheese (21), coffee (17), pork (7), poultry (6), eggs (4), milk (3), soy milk (1), and peas (under 1). Clearly, moving from a meat to a vegetable-based diet reduces emissions significantly.

However, feeding seaweed to cattle can reduce methane by 80 per cent, and “paddock grazing” of cattle actually stores substantial carbon in the soil.

The remaining agricultural emissions are direct use of fossil fuels and electricity (11 per cent), and the steel in machinery (4 per cent). These can be reduced as discussed earlier.

Waste & others (seven per cent) These emissions are mostly methane from landfills and wastewater treatment. An amazing 58 per cent of food in Canada is lost or wasted. We must reduce our waste and capture the methane, as is being done in the City of Peterborough’s wastewater plant. The waste composting facility being developed by the city will reduce the amount of organic waste going to landfills and provide compost for enriching gardens with less fertilizer.

What can individuals do?

We can reduce our personal emissions by what we eat and waste, and how much we drive. However, the above discussion shows we must focus on making our governments develop the regulations and incentives necessary to reach their reduction targets. Canada’s price on carbon and the Net-Zero Emissions Accountability Act (June 2021) have started the process but are not enough. It is also crucial to talk to our friends about climate change to broaden the conversation and awareness.