By Lethbridge Herald on July 15, 2020.
Marc R. Roussel
University of Lethbridge
I was dismayed to read the guest column by Mr. Cosmos Voutsinos published in The Herald on June 30. I realize that the newspaper takes no responsibility for the contents of guest columns, but a few minutes of thinking and some basic familiarity with the current scale of carbon dioxide emissions would have revealed the flaw in Mr. Voutsinos’ argument.
He points out that carbon dioxide levels measured at the Mauna Loa observatory have continued to increase through the early part of 2020. Well of course they did! Atmospheric carbon dioxide levels have been rising since the dawn of industrialization, and we emit far more carbon dioxide now than we did even a few years ago.
Let’s look at some numbers: Light-duty vehicles (including personal vehicles, but also including many commercial delivery vehicles) account for about 17 per cent of carbon dioxide emissions, and aviation for about three per cent (source: U.S. EPA). Electricity generation accounts for a further 28 per cent of emissions, and industrial activity for 22 per cent, while commerce is responsible for six per cent of direct emissions.
Let’s say for the sake of argument that all light-duty vehicles worldwide were parked, and all planes grounded. This would result in a reduction in emissions of 20 per cent, a dramatic overestimate given that many smaller vehicles were still driven and many planes still flew. The International Energy Agency reports that electricity consumption decreased by about 20 per cent in industrialized countries during the lockdowns. This in itself would result in a decrease in emissions of about six per cent.
A lot of electricity is used by industry, so let’s assume a similar reduction in industrial activity, responsible for about a further decrease in emissions of four per cent. And let’s suppose a 50-per-cent reduction in commercial activity, resulting in another three-per-cent decrease in carbon emissions. In total, that would add up to a decrease in carbon emissions of 33 per cent. Note that I deliberately overestimated the reduction in carbon emissions in several of the categories above. Current annual worldwide anthropogenic carbon dioxide emissions are about 35 gigatonnes.
A 33-per-cent reduction, even if it were to last all year, would roll our carbon emissions back to 2000 levels. And atmospheric carbon dioxide levels were definitely rising in 2000. But let’s say that I have missed some important sources of reductions in carbon emissions. Let’s say that our global carbon dioxide emissions have actually gone down 40 per cent. That would bring us roughly back to 1990 emission levels. Still a level of emissions at which carbon dioxide levels rise.
We need good, solid information about climate change from The Herald. The calculations above hint at how hard the problem is. Mr. Voutsinos’ misleading column does The Herald’s readers a great disservice.
Marc R. Roussel is a professor in the Department of Chemistry and Biochemistry at the University of Lethbridge.