Plant material explained: Canadian Geographic Magazine À la Carte

NEWSLETTER

magazine / nd04

November/December 2004 issue

À LA CARTE

Balancing act
Plant material is the basic fuel of life: we grow it, then eat it, wear it or burn it. A global accounting of who consumes what shows which nations are in the black and which are in the red
By Jodi Di Menna

Click map to enlarge

If plant material were money, a balance sheet recording what each nation produces and how much it uses for food, fibre and fuel would reveal which countries are self-reliant and which are stretched beyond their means. By mapping the net results (top), scientists have pinpointed regions most vulnerable to political and environmental challenges because of overconsumption or underproduction.

Areas of the globe where populations use more plant material than their agricultural and natural environments produce locally appear in red on the map. As a result, these regions leave the heaviest footprint on their ecosystems, are most dependent on imports to support their population and are at risk of catastrophic social collapse from changes in climate or trade.

Remarkably, despite having the highest per-capita consumption of plant material in the world, Canada is living within its means. It has the plant-producing engine of the boreal forest coupled with a sparse population to thank for its good credit. (The study did not take into account the consumption of fossil fuels.) In fact, North Americans consume only 24 percent of the plants they produce, just 4 percent higher than the global mean, compared with more than 70 percent for western Europeans and more than 80 percent for south-central Asians.

But Canada shouldn't squander its assets, warns Taylor Ricketts, an author of the balance-sheet study published in Nature in June, since we have to support the massive debt load of our big cities. Places like Vancouver, Calgary, Toronto and Montréal "are on a form of life-support," he says. "Energy has to fl ow into them at amazing rates from surrounding ecosystems."

Humans need to keep better tabs on the consumption of vegetation, says Ricketts. "We are a single species, and our numbers are relatively very small. Still, we take 20 to 40 percent of the primary resource that runs the world. There is a limit to this source of energy from the sun. We need to find ways to use it much more efficiently."

Charting consumption [click here to enlarge]
North Americans use more food, fibre and wood per person than the rest of the world. If not for our relatively sparse population and rich vegetation, our consumption habits would push us well into the red.