Aedes Albopictus, the "Asian Tiger Mosquito," courtesy of Wikipedia

The fall has been so full of climate change-related seminars that I earlier forgot to write up this one:  a day on The Health Impacts of Climate Change at Stockholm’s prestigious Karolinska Institute (Oct 11, 2011).  (Here I must reveal that my wife works at the Institute, Sweden’s leading medical training and research center, as its sustainability coordinator.)

All climate seminars start with a review of the science, and this one had the benefit of local expert Henning Rodhe, who divided the topic in two:  things we “know for sure,” and things that are merely “likely.” The physics of the greenhouse effect is in the “for sure” column — and that puts a minimum temperature rise of 0.5 to 1.0 degrees C., the melting of sea ice, and a sea level rise of at least 200 cm in the “for sure” column as well.

What’s merely “likely,” for example, is that shade, or “negative forcing,” of the aerosol particles we have put into the atmosphere are roughly balanced by the warming effect, or “positive forcing,” of CO2 itself. Take away the aerosols, up goes the temperature still more.

And “likely” is accompanied by another, bigger word, “uncertainty,” which translate to things like 1-6 extra degrees of warming by 2100, or up to a meter of sea level rise. Because the largest uncertainty, noted Rodhe, relates to what we humans are actually going to do about all this in the coming years.

The health-related star of the show was Tony McMichael of Australia, an IPCC author and a very thoughtful epidemiologist whose remarks ranged over a much broader terrain than just “health” — though human health is, in McMichael’s terms, the “anthropocentric bottom line” when it comes to thinking about all global ecosystem impacts …

Climate change not only impacts whole populations of people, indeed an entire global of people; it also impacts many future generations of people as well. Researchers tend to stay in a fairly prescribed comfort zone, said McMichael, where specific phenomena can be measured with precision. But the impacts of climate change on health stretch far outside that comfort zone, to global impacts with very fuzzy boundaries. So, what does it mean to be an expert on climate change and health? “We don’t actually know what the criteria for expert judgment would be,” said McMichael, even just relative to climate’s observed impact on health today, much less in the future.

Other presentations during the course of the day brought us up to speed on lovely things like the northward spread of “blue tongue virus”  (fortunately, this affects only farm animals, not us directly) and dengue fever (which, unfortunately, can kill you more directly). Yes, climate change may actually increase food production in some places — surely a plus for health security — but it will reduce it in others. And as is typically the case, the increases will likely happen in those countries we call “developed,” while the decreases will happen in the ones we call “developing,” that is, poor. We looked at close-up photographs of ticks (they like the warmer weather, and start living their lives in a sort of sped-up fashion thanks to the extra energy available for their metabolism), and we looked at a menagerie of mosquitoes caring the ever-popular malaria parasite. One of these, albopictus, spread from the coast of France deep into the interior in just five years. We also learn about some really horrid diseases I never heard of (check out the Wikipedia entry on “Leishmaniasis“.

Malaria, of course, is hardly new to Sweden; but we had successfully eradicated it, by moving our animals out into separate barns (mosquitoes are more attracted to animals than people). It turns out that improving your socio-economic conditions is the trick in preventing malaria:  people in African villages who have electric lights are less likely to get it, because a lit-up village is less attractive to a mosquito. The equation (according to researcher Elizabet Lindgren, Karolinska’s expert in such matters and the lead organizer of the seminar) is the following: climate change *plus* general socio-economic vulnerability *equals* increased risk of disease.

This creates a truly wicked problem, in system terms, because climate change is also *affecting* socio-economic vulnerability. And the actions we generally take to improve our socio-economic conditions — such as turning on the electric lights, building separate houses for our animals, and other things that we in Sweden certainly don’t want to abandon — usually help cause climate change. Hmm.

Between the disease migration, the impacts on agriculture, and of course the direct threats of things like record heat waves (which famously killed tens of thousands of folks during the last few years — Russia experienced its hottest summer ever just last year), and a few other nasty factors, climate change lived up to its portrayal as a “health risk multiplier” of the first order.

Will that make it McMichael’s “anthropocentric bottom line” that finally pushes us to more accelerated action?  Now I editorialize, and note that the historical record regarding how humans react to early warnings and clearly communicated health risks is, well, not great. It took millions dying of cancer to wake us up to the dangers of cigarettes, which we still happily sell and smoke, despite the big “THIS WILL KILL YOU” notices on the packages that are required these days.

So I’m afraid it’s going to take more than a doctor’s warning to stop us from smoking fossil fuels …