Source: The Keeling Curve, Scripps Institution of Oceanography at UC San Diego
While observed CO2 concentration barely glanced it for the first time ever last Spring, the 400 parts per million (ppm) level was clearly breached last month (April 2014). The figure is a significant milestone. A plurality of environmental scientists have noted that exceeding the 400 ppm CO2 concentration levels will ” make it progressively more and more difficult to avoid further substantial climate change.”
Some critics simply dismiss science and scientists out of hand, to rather humorous effect (Doomsaying math whizzes just don’t understand capitalism Brian Lee Crowley, The Globe and Mail, March 21, 2014). Others proffer more thoughtful, nuanced equivocations. For example, some suggest if humans indeed had any impact on the rapid rise in CO2 concentration over the past half century, the human population explosion is the more likely culprit.
While there certainly is a historical correlation between population growth (PDF) and CO2 concentration, as the old adage goes, correlation is not causation. What that increasing population has been doing and, more importantly, how it’s been doing it has been the primary focus of most contemporary research on the topic.
So where does Canada fit into this picture? Facing increased scrutiny over its environmental record, it doesn’t help that Canada’s per capita fossil-fuel CO2 emissions are among the highest in the world, and, despite the country’s relatively tiny population, that Canada’s total fossil-fuel CO2 emissions are also among the highest in the world.
If there’s one thing Canadian policy-makers can hang their hats on, it’s that Canada’s overall share of industrial CO2 emissions hasn’t risen as much as some developing market economies’.