Hey there, time traveller!
This article was published 5/7/2016 (353 days ago), so information in it may no longer be current.
This week, our Three Amigos — Canadian Prime Minister Justin Trudeau, U.S. President Barack Obama, and Mexican President Enrique Peña Nieto — reiterated commitments to climate change mitigation and a greener energy sector with higher percentages of renewable energy. This is all commendable and predictable given Canadian, American and Mexican commitments to the Paris Climate Change Agreement to limit global warming to 1.5 degrees.
The more surprising outcome of the North American Leaders Summit was a commitment to accelerate research and development on clean technology projects such as "the capture of carbon dioxide for use as an industrial feedstock or for sequestration underground."
The implication is policymakers are quite seriously coming to terms with the technical challenge of achieving the Paris 1.5 C target, and the benefits of doing so — all of which bears directly on climate adaptation and mitigation policy for the Canadian Prairies.
There is relatively little research that has looked specifically at the 1.5 C warming scenario, but there is some and what does exist shows a big advantage in achieving the Paris target.
Last year, a study by Erich Fischer of the Institute for Atmospheric and Climate Science in Zurich found the risk of very hot days increases significantly in the gap between 1.5 and 2 C. The likelihood of experiencing what was a once-in-a-thousand-days hot day has already increased fivefold. According to Fischer, the likelihood of such extremely hot weather doubles again at 1.5 C and doubles again if we go to 2 C.
The Prairie Climate Atlas tells the story well — for Winnipeg, which currently experiences about 12 hot days a year (above 30 C), by the latter decades of this century, that number could rise to more than 40 days a year, at which point we’d have a climate resembling present-day north Texas.
The environmental and political logic of the Paris target is obvious — it’s the technical challenge of limiting global warming to 1.5 C that makes the story even more interesting. As of several weeks ago, the last holdout climate station in the world (in Antarctica) reported an atmospheric CO2 concentration above 400 parts per million (ppm). Every station in the world is now reporting more than 400 ppm.
The current crop of global circulation models generally agrees that limiting warming to 1.5 C requires atmospheric CO2 to rise no further than 430 ppm, which means 300 billion tonnes of CO2 can be added to the atmosphere. However, even a very aggressive mitigation strategy that drops global CO2 emissions to zero by 2050 and stays at zero for the rest of the century produces 800 billion tonnes of additional CO2. So, how do we resolve this rather fundamental 500-billion-tonne gap to achieve 1.5 degrees?
According to Joeri Rogelj and his colleagues at the International Institute for Applied Systems Analysis in Austria, the answer is simple and inescapable — we use carbon dioxide removal (CDR) technology. It has existed on the fringes of climate science and policy for decades and has been considered, like climate adaptation (until recently), a distraction to the priority task of cutting CO2 emissions. That may have been true in 1980 or even 1990, but Rogelj’s modelling shows we’ve waited too long, and without CDR, no plausible pathway exists to limit warming to 1.5 C by 2100. What were once rather outlandish ideas now have to be on the table — the math doesn’t pencil out any other way.
So what is CDR? As the name implies, it’s technology that removes CO2 from the atmosphere and ideally locks it up permanently. At its simplest it can be afforestation (planting trees) and managing agricultural soils to sequester more carbon in its organic matter. More complex approaches use energy to chemically strip CO2 molecules from ambient air to produce a pure CO2 stream for use in industrial applications or geological sequestration.
So what are the stakes for the Prairies? We know the effects from climate change are amplified on the Prairies, and we’ll likely reap disproportionate benefit by limiting global warming to 1.5 degrees. Moreover, the CDR technologies required to achieve 1.5 C have one thing in common — they need productive geography to work, whether for afforestation, soil carbon sequestration or the renewable energy to power CDR.
And a lot of productive geography is one attribute the Canadian Prairies have in spades. Let’s keep it that way.
Hank Venema is director of planning at the Prairie Climate Centre.