Canada's CO2 emissions from the oilsands may be much higher than has been reported by industry.

Environment and Climate Change Canada scientists — including John Liggio, from the Air Quality Research Division — collected air samples over four major surface mining oilsands operations over a six week period in 2013 and found evidence of CO2 emissions more than 60 per cent higher than industry had calculated.

At one site, the gap between what had been reported and what the scientists calculated was 123 per cent. This new research could mean that Canada's carbon emissions are significantly higher than we'd thought.

This could make meeting our commitments for emission reductions that much harder to meet.

Environment and Climate Change Canada air quality research aircraft. (Air Quality Research Division, Environment and Climate Change Canada)

Why is there a discrepancy?

The industry technique for calculating CO2 emissions in Canada is based not on measurements, but on complicated calculations that add up emissions from vehicles, mining, processing, maintenance and tailings ponds. This is a difficult accounting process that is meant to account for all possible emission sources from oilsands production.

The Environment Canada numbers were arrived at very differently. They made direct atmospheric measurements of CO2 concentrations by doing multiple flyovers of four major oilsands operations over six weeks using a specially equipped aircraft. They used these measurements to calculate total emissions from the facilities.

Equipment used to gather air quality data inside the research aircraft. (Air Quality Research Division, Environment and Climate Change Canada)

Emissions by numbers

The researchers' calculations using this "top-down" technique resulted in higher numbers than had been reported from the industries' "bottom-up" calculation method.

The discrepancy ranged from 13 per cent at the Suncor's Millenium and North Steepbank site, to 123 per cent at Syncrude Canada's Mildred Lake site. The Canadian Natural Resources Horizon Mine and Jackpine (formerly Shell) sites resulted in differences of 36 per cent and 38 per cent respectively.

Overall the researchers calculated that these four sites exceeded their reported emissions by 64 per cent. That means 17 additional megatonnes of CO2 were emitted by these oilsands operations in the year of measurement. This is a significant addition to the more than 700 megatonnes Canada produces in total each year.

Dr. Liggio said the discrepancy between the numbers produced by his team and industry numbers needs to be explored. He admits that it's possible that neither set of numbers is precisely correct, but that his team has great confidence in their findings.

A Suncor facility in Alberta's oilsands. (Air Quality Research Division, Environment and Climate Change Canada)

We'll always have Paris

By the terms of the Paris Agreement, Canada promised to reduce CO2 emissions by 30 per cent by the year 2030 from 2005 levels.

Canada's commitment will not change, but according to the new numbers generated by this study, achieving that goal will become more difficult. In fact, the challenge may be even greater, as the study did not include all oilsands operations. So in the end the gap between industry numbers and those gathered using the "top-down" air sampling method could be much greater.