Frequently Asked Questions About Climate Change

Have questions about climate change? Here are a few questions and answers to help get you started. For more information, check out our climate change resources or see our related websites list for other helpful resources.

How will climate change affect agriculture in Canada?

Climate change will have a variety of effects on agriculture. Increased temperatures may lengthen prairie growing seasons, with the possibility of increased production in northern regions; however, these regions are limited by soil capability. It must also be kept in mind that while a rise in temperature may mean a longer growing season and arable area, it will also have other, adverse affects. Current trends indicate that the prairie climate of the future will feature increased temperatures, a lack of moisture and increased rates of evaporation.

These factors could result in severe droughts, while hot, dry temperatures will create more favorable conditions for weeds and insects. There will also be a risk of poor herbicide performance. Taken together, these changes could reduce the potential of crop yields. Livestock production would be affected as well. Insects and diseases that livestock are unaccustomed to would move into their area as climate changed. While cold stress on animals would decrease in the winter, this advantage would be offset by an increase in heat stress during the summer.

Climate change will modify rainfall, evaporation, runoff, and soil moisture storage. With a warmer, dryer climate, there will be increased pressure to develop crop varieties resistant to drought. Agriculture is the largest consumer of water in arid and semi-arid regions like the Canadian Prairies -- climate change would mean good quality water supplies would become even more crucial and contentious than they are today.

Which gases are the largest contributors to global warming?

Next to water vapour, carbon dioxide gas (CO2), released when coal, oil, or natural gas are burned to produce electricity, heat, and transportation, is the largest contributor to global warming. Methane (CH4), another large contributor to climate change, is released through rice fields, digestive waste from ruminant animals (cattle, sheep, wild animals), coal mining, wetlands and natural gas venting, and biomass burning (incomplete combustion). Nitrogen oxide (N2O)is another greenhouse gas. It is released through the use of nitrogen fertilizers, wood burning, and some industrial processes.

What amount of greenhouse gases are in our atmosphere right now?

Before the Industrial Revolution of 1750-1800, levels of C02 were recorded at about 280 parts per millionth volume, or ppmv. These levels have steadily risen since. In 1958, levels were at 315 ppmv, in 1990, they were at 353 ppmv. In the spring of 2001, the levels were measured at roughly 375 ppmv. In the past 200-250 years, the amount of methane in our atmosphere has risen as well, from 0.8 ppmv to roughly 1.75 ppmv in spring 2001. Nitrous Oxide (N2O) has increased from .28 ppmv in the pre-industrial era, to current rates of roughly .31 ppmv.

Which greenhouse gases are created by Canadian agriculture?

A. Agriculture and Agri-Food Canada estimates that agriculture accounts for 10 per cent of Canada's total greenhouse gas emissions. Livestock and manure account for 58 per cent of these gases; crops for 37 per cent. About two-thirds of these gases are in the form of nitrogen oxide, or N20, while one-third of these gases are CH4, or methane. The production of carbon dioxide levels through agriculture have abated to an almost negligible amount. However, agriculture can be useful in sequestering, or trapping, carbon from our atmosphere.

Which best management practices work best to reduce climate change?

There are a number of ways that producers can manage their operations to make them as environmentally friendly as possible. Agriculture can help minimize the impact of climate change if producers:

• Plant trees and shrubs to store carbon dioxide
• Convert from traditional plowing practices to conservation tillage (reduced or zero-till)
• Grow cover crops during the winter, such as alfalfa or hay
• Let marginal lands rest (i.e. take these lands out of production)
• Rotate crops to preserve soils
• Plant vegetation with deeper roots to prevent soil erosion
• Store manure as compost.

While there will always be some emissions of greenhouse gases through agriculture, improved farm management will ensure a reduction of these gases to an acceptable level. Improved practices might even mean a net removal of carbon dioxide from the atmosphere through its storage in soils.

What is the best way to reduce methane emissions when storing manure?

How manure is stored can affect the amount of greenhouse gases it emits. Methane and nitrous oxide emissions are smaller for compost than for slurry or stockpile. In terms of dairy manure, slurry emits 1.9 times more greenhouse gases than compost; stockpiled manure emits 1.5 times more. For beef manure, emissions of methane and nitrous oxide are much lower than in dairy. Slurry emitted 4-6 times more gases than compost, while stockpiling was 1.3 times higher than compost.

How valuable are trees for preventing climate change?

Trees are a valuable tool in the fight against climate change, as researchers at the Shelterbelt Centre have discovered. Their work has determined how much carbon is fixed in a variety of tree species. The results prove that shelterbelts are extremely useful in sequestering greenhouse gases.

A mature poplar tree sequesters 266 kg of carbon, green ash traps 63 kgs; a white spruce tree will capture 143 kg, and a caragana tree will sequester 39 kg. At the recommended spacings for shelterbelts, these values translate into 106 tonnes per km for poplar, 25 t/km for green ash, 41 t/km for white spruce, and 26 t/km for caragana. These figures don't include the amount of carbon that will become sequestered in the trees roots, which may equal roughly 50 to 75 per cent of these amounts.

On top of these benefits, shelterbelts also reduce energy usage. While a homestead is protected by a mature shelterbelt, its heating bills will be reduced by as much as 25 per cent. This means a reduction in fossil fuel use.