Page 44 - RealDirtENG2020

Farming’s carbon footprint
Greenhouse gases (GHGs), including carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O), absorb radiation from the sun and trap heat in the atmosphere, effectively acting like a greenhouse or a layer of insulation for Earth. GHGs are part of the earth’s natural processes, but human activities over the last several centuries have increased GHG levels far past where they should be. This change has very negative consequences for our climate, including increasing global temperatures, and more frequent episodes of severe weather.
CO2 is produced by farm equipment. It’s also released when soil is disturbed, or when plants decay. N2O emissions are primarily
a result of fertilizer use, including manure. Methane is a natural by-product of digestion in the stomachs of ruminants, as well as from manure from farm animals.
GHG emissions from Canadian agriculture have stayed about the same for the last
20 years95, even though food production has increased dramatically. That status is mostly because farms have become more ef cient—they’re able to grow and raise more food while using less land, water, and fuel. This change also re ects the increased carbon sequestration in crop land. Canadian farmland, particularly in the Prairies, captures more carbon than it releases. That makes it a carbon sink96.
The environmental impact of raising livestock can vary a lot. Feed quality, genetics, and the part of the world in which the animal is being raised, are just three factors. Modern advances in genetics, nutrition, and other areas of science have led to more environmentally-ef cient animals, and farmers and scientists continue to work towards reducing the amount of methane produced by livestock.
Consider this fact: Today, every kilogram of Canadian beef is produced using 17
per cent less water, 24 per cent less land, and generates 15 per cent less greenhouse gases, than the same amount of beef produced 30 years ago97.
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Canada’s total GHG emissions are about 1.6 per cent of global emissions; of that amount, 8.4 per cent can be attributed to agriculture—and only about four per cent comes from livestock98.
Livestock as part of the solution
Sustainably-managed livestock populations are also very much part of the solution to the climate change challenge, and play a signi cant role in our ecosystems.
Less than eight per cent of Canada’s land is used for agriculture. The rest has been developed as an urban landscape, is forest
or shrubland, or is very dif cult to impossible to grow crops on (think Arctic regions). But livestock can ourish on terrain that’s too rocky, hilly, wet, or dry. That gives farmers the opportunity to produce food in places where crops can’t grow.
Temperate grasslands, like those found in the southern parts of the Prairie provinces, are among some of the most endangered ecosystems in the world. They support biodiversity by providing widely ranging wildlife habitats, hold water during oods, and provide drinking water for people and wildlife. And because the land is not worked, the carbon captured by plants and put into the soil stays there as long as the land remains intact.
Unfortunately, less than 20 per cent of Canadian grasslands remain intact—most have been built over, or used for growing food99. Once these grasslands are lost, it is nearly impossible to replicate them.
Anna Haupt
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The Real Dirt on Farming
Eugene Ivanov