Extreme weather extremely costly | Science Matters | David Suzuki Foundation

By David Suzuki with Faisal Moola

Global warming may have been the last thing on the minds of Vancouverites as they dug out from a record November snowfall and cold snap. But it's another reminder of how much we all depend on the stability of our atmosphere.

While residents of other Canadian cities may scoff at Lotus land's relatively minor misfortunes, the city has certainly had its fair share of weather anomalies lately. First, record rains churned up rivers and caused landslides in the city's watersheds, leading to turbidity problems in the drinking water supply and a boil-water advisory across the region. Then, just as the water began to clear, a record cold and snowfall paralyzed the city.

What has this got to do with global warming? Well, extreme weather events like these are exactly the kind of thing climatologists say will become more common as our climate heats up. How confusing is that? Global warming can cause heavy snowfalls. But it's true.

This ability to link global warming to so many weather-related phenomena has created a bit of a joke: Blame everything on global warming. Stock market down? Global warming. Can't get a date? Global warming.

But underlying the joke is a serious fact. Our atmosphere is connected to everything — including us. By adding vast amounts of heat-trapping gases like carbon dioxide to the atmosphere (from our industries, cars and power plants) we're trapping more heat near the surface of the earth. More heat means more energy. Adding so much energy to our atmosphere creates the potential for more violent outbursts — like the weather Vancouver has been feeling lately.

This is why it's so imperative and urgent for humanity to get this problem under control. It's not as though global warming is just a minor inconvenience. Left unchecked, it's set to become a major hindrance to economic growth and international development. Vancouver newspapers were full of stories during both extreme weather events about how much these "natural" disasters were going to cost the city's economy.

In developing countries, severe weather events are doing more than harming the economy — they're killing people. Of course, extreme weather has always killed people. But in a recent article in the journal Science, Indian researchers report that extreme summer monsoon rains in India are becoming more common. Last summer, for example, more than 1,000 people died during one torrential rainstorm around Mumbai.

For the Science study, researchers analyzed data during the period 1951 to 2000 from more than 1,800 weather stations around central and eastern India. They found that while overall rainfall remained fairly consistent during the 50-year period, the number of extreme rainfall events doubled. Researchers cannot conclusively say that human-induced global warming is the cause, but the study's findings are in line with what computer models predict will continue to happen unless we seriously curb greenhouse gas emissions.

The new research helps shed light on why, when global warming models predict more rain in places like India, rainfall there doesn't seem to have increased overall. The answer is that, although annual average rainfall hasn't necessarily increased, extreme rainfalls have. That's unfortunate because more steady rainfall could actually benefit India's agriculture. Extreme weather benefits no one, especially in a developing country like India that lacks the infrastructure to deal with it.

Keep that in mind for Canada. Canadians by and large sure wouldn't mind more pleasant weather. But global warming won't benefit anyone if more extreme weather is the result. Just ask folks in Vancouver.

December 8, 2006
http://www.davidsuzuki.org/blogs/science-matters/2006/12/extreme-weather-extremely-costly/