Latest headlines

Monday, May 26, 2008

Quebec researchers predict steep rise in 'death by global warming'

Climate change isn't just threatening polar bears anymore -- Quebec residents will face more and more deaths by global warming during warmer and warmer summers in the coming decades, a team of Laval University researchers reported last week in the International Journal of Health Geographics.

By the year 2080, the study (PDF) found, Quebecers can expect to see between an 8% to 15% rise in mortality in the summer months, which translates to a total of up to 540 extra deaths per summer in Montreal alone compared to the 1981-1999 average, which the study uses as the baseline. Even a more conservative model of carbon dioxide emissions predicts 310 extra deaths. (In 2005, Dr Gosselin and other Canadian officials warned a United Nations conference in Montreal that climate change could conceivably kill 150,000 people a year worldwide.)

In the figure above, you can see the huge rise in summer mortality in Montreal predicted by the study.

Similar studies conducted in the United Kingdom have shown similar results for summer mortality, but the European data shows an overall yearly drop in mortality because of warmer winters. But this new study -- titled "The potential impact of climate change on annual and seasonal mortality for three cities in Quebec, Canada," by physician Pierre Gosselin, who heads the World Health Organization Collaborating Centre for Environmental and Occupational Health Impact Assessment and Surveillance, and researchers Diane Bélanger and Bernard Doyon -- found no such winter benefit, as you can see in the figure. Why? Because Quebecers are used to the cold already, so a giant snow storm or a weeks-long freeze doesn't have the same dangerous effect in Quebec as it does in more temperate regions, like the UK. The study explains:

"Over the years, Quebecers have developed various strategies to acclimatize to the cold. The Act respecting the conservation of energy in buildings (1983), aiming to ensure a minimum performance of the thermal insulation of walls and ceilings, is one example. Furthermore, natural resources ensure heating at a relatively low cost, and even among the most advantageous, compared to several industrialized countries including the United Kingdom."
American studies have shown similar results, the authors say, which proves that different regions and different circumstances will see vastly different mortality effects as a result of global warming.

The study is an extension to the three researchers' previous work, published (PDF; French only) in December 2006 by the National Public Health Institute of Quebec, which established the validity of the particular statistical model used in their new work.

The conclusion then was the same as the conclusion now: if carbon dioxide emissions aren't drastically cut in the coming years, global warming will begin taking its toll not just on polar bears and Antarctic icebergs, but on humans in first-world nations as well.

Figure: "The potential impact of climate change on annual and seasonal mortality for three cities in Quebec, Canada," Bernard Doyon, Diane Bélanger, Pierre Gosselin, International Journal of Health Geographics 2008, 7:23. link (PDF)

Check out our website:


  1. What is the corresponding number of lives saved from warmer winters?

  2. You might think that warmer winters would balance out the increased summer mortality caused by warmer weather -- and in fact that's what has been predicted in some European studies -- but this study showed that that logic will not apply in Quebec. Apparently, some American studies agree with the Quebec model, as well.

    It doesn't sound like the European studies are wrong, however. Nor are the Quebec/United States ones. Both may be correct, but warmer weather may simply have different consequences depending on the location. Place matters, as the Laval team puts it in the Discussion section of their study.

    (For a bit more on this, see the paragraph in the post above that begins "Similar studies conducted in the United Kingdom...")