If Justin Trudeau’s cabinet had approved the controversial Teck Frontier tar sands/oil sands mine this week, it would have given its blessing to a project that would dump 45 million tonnes of carbon dioxide or equivalent (CO2e) into the atmosphere, 11 times more than the company acknowledged, according to analysis completed in the days before the company’s dramatic decision to withdraw its project application.

The order-of-magnitude difference in the numbers turns on the standard practice of calculating the climate impact of oil and gas megaprojects based solely on the emissions produced to extract the product, but leaving out the much larger atmospheric assault when that product is sent to a customer and used as directed.

The full, all-in total was about equal to the CO2e the Greater Toronto and Hamilton Area (GTHA) would save if the whole region could bring its emissions to net-zero.

Canadians and indeed the world were watching to see how the cabinet weighed in on Teck’s $20.6-billion megaproject, which was expected to produce 260,000 barrels of bitumen per day if it had ever been built. This at a time when the world in general needs to honour its commitments to drastically reduce greenhouse gas (GHG) emissions, while Ottawa has promised a tougher emission reductions target for 2030 leading to net-zero by 2050. 

Just how significant were the emissions from this proposed project? Teck put emissions from the operation of the Frontier mine at about 4.1 million tonnes of CO2e per year. An estimate from climate organizations that included all the ancillary activities around this open pit mining project placed the annual emissions at 6.0 million tonnes.

But either way, that was just the start.

Diluted bitumen is not a benign product. This project was not intended to produce something innocuous like milk. The product of the Teck mine was diluted bitumen destined to be transported and refined into gasoline, oil, and other fuels. Burning those products would have generated about 41 million tonnes of CO2e per year—about 10 times the emissions from the project’s operation.

Together, the mine’s operations and its final products would have contributed at least 45 million tonnes of CO2e per year of new greenhouse gas emissions.

Humanity has already used up three-quarters of its global carbon budget, the amount of CO2 the atmosphere can absorb before human activity triggers irreversible climate catastrophe. The IPCC warned in 2018 that we must cut our carbon emissions about 50% by 2030 to get the climate crisis under control. And we must halve our carbon emissions in each of the following two decades to arrive at net-zero by 2050—which is the new Canadian target.

So how significant is 45 million tonnes of CO2e per year? For comparison, the entire Greater Toronto and Hamilton Area (GTHA) emits about 48 million tonnes per year, including the steel plants in Hamilton, emissions from solid waste, and all forms of energy across all sectors of the country’s biggest regional economy. The production and use from the Teck mine would have nearly equaled the emissions from the entire GTHA. 

Put another way, if the GTHA could somehow achieve net-zero carbon emissions, the Teck project alone would have negated that contribution to meeting Canada’s and the world’s climate change goals. Is that climate justice?

The new numbers show how closely our climate future was tied to the cabinet decision on the Teck project. Even though a Vancouver-based mining company ultimately took the decision out of our elected representatives’ hands, make no mistake: this was a bellwether moment for our future and the sort of world we are leaving for our children and grandchildren.

Brian Kelly was one of the founders of Pollution Probe in 1969 and was the second employee of the federal Office of Energy Conservation in 1974. After a career in environment and energy, he was most recently the climate lead for the Region of Durham in Ontario.