The inescapable math of climate change

Judged only by its title, the "national inventory report" sounds like something produced by a furniture retailer.

In fact, it might be the second-most significant document published by the federal government each year — surpassed only by the annual budget.

The annual account of Canada's greenhouse gas emissions was released on April 14, just as most of Ottawa was fixated on the uneventful testimony Justin Trudeau's chief of staff was giving to a parliamentary hearing on foreign interference.

Six days later, with even less fanfare, Environment Minister Steven Guilbeault announced that the government would be updating its estimate of the "social cost of carbon," an internal calculation used for performing cost-benefit analyses of federal regulations.

Put together, the national inventory report and the social cost of carbon lay out the inescapable math of climate change. And they fill in some of the facts that have been missing from the latest skirmish in the interminable fight over carbon pricing in Canada.

The latest tally of emissions includes some encouraging news, at least. In 2021 (emissions data always takes a little over a year to process), Canada's GHG emissions totalled 670 megatonnes. That's the second-lowest annual total since 1996.

The total for 2021 does represent an increase of 12 Mt over 2020. But because 2020 was such an unusual year — for most of the year, the activity of individuals and businesses was severely curtailed by pandemic health restrictions — it defies comparison.

A better point of reference might be 2019. In that pre-pandemic year, Canada's emissions were 724 Mt.

Measured against that baseline, 2021 suggests that GHG emissions in Canada have finally started to decline. That's certainly Guilbeault's view; he said this week that "the bottom line is that Canada is bending the emission curve downward."

The results for 2021 are at least well below what earlier projections expected emissions to be around now. A federal estimate published in 2014 estimated that Canada's total emissions in 2020 would be 727 Mt. An update published in 2016 projected Canada's emissions would be between 749 Mt and 790 Mt in 2020.

Because 2021 was also affected by pandemic health restrictions, it's hard to know exactly what a "normal" year would have looked like — or predict what 2022's data might look like. But in a presentation to a climate conference in Ottawa last week, Dale Beugin of the Canadian Climate Institute said there is evidence that recently adopted climate policies are beginning to have an impact.

He also noted that "sector-level progress isn't symmetric." That's an understatement.

Compared to 2005, Canada's total emissions have fallen by 62 Mt, but that national result obscures profound differences across six economic sectors. Total emissions from electricity have fallen from 118 Mt to 52 Mt — significantly assisted by the phase-outs of coal-powered generation in Ontario and Alberta.

At the other end of the spectrum, oil and gas emissions have risen from 168 Mt to 189 Mt and now represent 28 per cent of Canada's total emissions.