Air

Greenhouse gases

Greenhouse gases such as carbon dioxide, methane, water vapor and nitrous oxide contribute to the greenhouse effect, a natural phenomenon that traps heat in the atmosphere. The gases result from natural processes (such as volcanoes, cloud cover, ocean currents and plant transpiration) and human activities (such as breathing, burning of fossil fuels and emissions from landfills).

Since industrialization, human activities such as the burning of fossil fuels have increased the amount of greenhouse gases emitted into the atmosphere. Many, but not all, scientists believe that increased emissions have enhanced the greenhouse effect, causing the atmosphere to warm and the climate to change.

Some environmentalists and scientists predict that rapid and continued warming of the Earth’s temperature could trigger the following changes:

• increased temperatures of air and water around the world
• melting glaciers and increased sea levels
• impacts on water resources and availability
• extreme weather events (such as floods and droughts)
• health impacts (such as heat stress and the spread of infectious diseases)
• longer growing seasons in northern climates
• increased vegetation growth

Recent changes in weather patterns globally and in Canada have heightened public concern about the climate change issue. Although there is still scientific debate about the linkage between these events and greenhouse gas-caused climate change, there is increasing international pressure to slow the growth in human-caused greenhouse gases.

In 2000, according to Environment Canada estimates, the upstream oil and gas industry in Canada accounted for about 97 million tonnes of carbon dioxide equivalent — or 13 per cent of Canada’s total greenhouse gas emissions. Emissions from upstream oil and gas operations include:

• combustion emissions from energy use during exploration and extraction of oil and gas, upgrading oilsands and transmission of natural gas
• fugitive emissions that may occur during exploration, production and transport
• process emissions from extraction of hydrogen from natural gas (used in heavy oil upgrading)

From 1990 to 2000, the Canadian upstream industry’s emissions grew about 54 per cent, largely because of increased production to meet the growth in oil and gas exports, mainly to the United States. However, efficiency improvements in operations are contributing to emission intensity improvements in the industry. For example, the oilsands industry will soon produce 45 per cent less emissions per unit of production, compared with 1990.

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