Canadians are a well-fed bunch. We do not generally have to worry about our food supply. For most of us, it’s just a matter of heading to the nearest grocery store. But global warming could gradually change what we eat and how we get it.


As global warming develops we are more likely to get longer periods of drought, for example, and heat waves could become more frequent or more intense. That could pose serious problems for our farmers, especially on the Prairies.

But if global warming also lengthens the growing season, could it have a beneficial impact on farming in Canada?

Carbon dioxide (the main greenhouse gas) can actually enhance plant growth.

Commercial growers often add carbon dioxide to the air inside their greenhouses.

Because of these benefits some people believe that, although global warming will force changes to where and how we farm, it might have an overall net benefit to Canadian agriculture. Could this really be an upside?

The issue is not that simple. Nature is often far more complex than we anticipate, and that’s certainly the case with how plants respond to changes.

As it turns out, higher carbon dioxide levels have other effects on plants and not all are good. Many crops won’t just grow faster in an enhanced carbon dioxide environment, they will grow differently.

Studies done on plants raised with higher levels of carbon dioxide show they contain less protein, which makes them less nutritious for humans, as well as everything else that eats them. This could have implications throughout the food chain, because many creatures depend entirely on plant-based proteins — including important livestock like cattle.

Also, the type of protein produced by plants in higher carbon dioxide environments also changes. Bread, for example, depends on a specific kind of protein called gluten, which is key to making bread rise. Other foods could be affected, too.

Global warming is a serious problem and when everything is connected, you never know what one change in the natural world will mean to the entire system. We just have to remember that, ultimately, whatever changes we make will come back to us in the end.

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Dr. David T. Suzuki is an award-winning scientist, environmentalist and broadcaster. He is the co-founder of the David Suzuki Foundation in Vancouver where he lives with his wife and two daughters.

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