Science Matters by David Suzuki

Feeding six billion people is no easy task. Feeding nine billion will be a tremendous challenge, especially without substantially degrading the natural systems that we ultimately depend on - systems that provide us with clean air, water and soils.

Yet it’s a challenge we currently face, as the world’s population is expected to swell by 50 per cent in the next 50 years. At current rates of expansion and using conventional farming methods, this will necessitate the conversion of an additional billion hectares (larger than all of Canada) of natural ecosystems into farmland - putting a tremendous strain on ecosystems and on individual species.

Arguably, no other activity has had as much impact on humanity, and the planet, as has agriculture. Agriculture has allowed humans to settle down, build cities and sophisticated civilizations. It has also allowed our population to explode.

But the benefits have not come without costs, especially since the "green revolution" of the 20th century that brought about today’s large-scale industrial farming methods based on mechanization, irrigation and heavy applications of nitrogen fertilizer and pesticides. Although these new farming methods doubled global grain production and reduced hunger, they also wiped out many small family farms and concentrated ownership among large corporations. Furthermore, the techniques used increased soil erosion, incidence of crop disease, contamination of groundwater and the eutrophication (oxygen depletion caused by uncontrolled plant growth) of freshwater and marine ecosystems due to fertilizer run-off.

In fact, humans now release as much nitrogen and phosphorus into terrestrial (land-based) ecosystems as all natural sources combined. We have appropriated one-third of the productive capacity of these ecosystems for agriculture and use about half of all available freshwater. Yet demands are still increasing. A growing population and increasing demand for meat (a highly inefficient form of food production) from wealthier nations means that by 2050, irrigated areas are expected to almost double in size, greatly increasing our use of freshwater, while nitrogen fertilizer application is forecast to virtually triple. Meanwhile, global production of pesticides is predicted to increase by 270 per cent. These additional burdens are expected to have highly detrimental effects on water and soil quality, biodiversity, and potentially human health.

That’s why finding less damaging methods to feed the world population is such an important task. One alternative method may be organic farming, which eliminates pesticides and requires far less of other chemical inputs. Although some critics argue that organic farming can reduce yields and thus increase pressures on the natural world, studies have shown that organic practices for some crops can maintain yields, while greatly reducing overall impact. Another possibility is the use of genetic modification.

Although this radical new technology is largely untested and in its infancy, it may play a role in a sustainable agricultural future, if found to be safe.

In Europe, about 20 per cent of the farmland is already regulated by various plans attempting to reduce the impact of modern agriculture on the environment. But a recent study published in the journal Nature found that the success of these plans is mixed. For example, one plan’s goal is to increase the diversity of plant, insect and bird species by paying farmers to delay mowing or grazing on their fields, in order to give nesting birds time to hatch chicks. Unfortunately, the study found that this costly practice seems to have had no positive effect on bird species diversity. However, other methods to improve biodiversity such as leaving crop stubble in fields overwinter are expected to have better results.

Any attempts to reduce the negative impact of agriculture on the Earth should be applauded. As we search for a balance between the need to feed ourselves and the need to maintain healthy ecosystems (which in many ways are the same goal), there will always be failures as well as successes. The key is to build on the success and learn from the failures to find a path that is sustainable.

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