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Greenhouse gases and climate change

Since 1972 North America's climate has warmed considerably, reflecting a global trend. About half of the average rise in North America's surface temperature during the past century - more than 0.6 C - occurred since the late 1970s (see graph). North America emits more greenhouse gas than any other region, accounting for around 5 per cent of the world's population but nearly 26 per cent of global anthropogenic emissions of CO2 in 1998 (Marland, Boden and Andres 2001). North America has one of the world's most energy-consuming economies. The transportation sector is the largest source of CO2 emissions, accounting for 30.1 per cent of Canada's emissions in 1995 (EC 1998a) while in 1993 cars and light trucks were responsible for more than 20 per cent of US CO2 emissions (Glick undated). In 1997, the US transport sector accounted for around 5 per cent of global anthropogenic CO2 emitted and more than one-third of total world transportation energy use (NRC 1997, O'Meara Sheehan 2001).

Average temperatures in the United States (C)

Average annual temperatures in the United States have increased more than 0.6C since the late 1970s

Source: DOC, NOAA and NCDC 2000

Two sharp price shocks in the oil market in the 1970s helped to increase awareness that oil is not a renewable resource. Energy-saving standards for vehicle bodies, engines and fuel efficiency in new passenger cars were introduced in the 1970s and strengthened in the 1980s (OECD 1996, CEQ 1997). However, a combination of factors conspired to drive energy use up during the 1980s. Progress in total and per capita energy efficiency slowed and CO2 emissions continued to rise (CEQ 1997, EC 1997, OECD 1998).

Renewed efforts subsequent to the UNFCCC commitments also failed to curb CO2 emissions in the 1990s. In 1998, emissions were 14 and 11 per cent above 1990 levels in Canada and the United States respectively (US EPA 2000a, SRP 2000). Renewable energy production from hydropower, wind, solar, biomass and geothermal sources is increasing but still contributes only a small fraction of energy needs, supplying about 7 per cent of US domestic energy demand in 2000 (US EIA 2001).

In the transport sector, progress made in car fuel efficiency and emission controls has been partially offset by increases in the number of automobiles, in distances travelled, and a trend since 1984 toward lightduty trucks and sport-utility vehicles (CEQ 1997, EC 1998a). For example, between 1990 and 1995 there was a 15 per cent increase in automobile travel in Canada, a decrease in urban transit usage and a 6 per cent increase in total fossil fuel use (EC 1998b). In 1994, nearly 60 per cent of US households owned two or more cars and 19 per cent owned three or more (De Souza 1999). Cheap parking and other hidden subsidies, such as funds for highway development and low fuel prices, have encouraged car dependency (Miller and Moffat 1993, EC 1998a).

Under the 1997 Kyoto Protocol, Canada agreed to reduce greenhouse gas emissions to 6 per cent and the United States to 7 per cent below 1990 levels between 2008 and 2012. However, in early 2001, the United States announced that implementing the Kyoto treaty would be too harmful to the economy and that it would pursue other ways of addressing climate change (US EIA 2001). At the July 2001 UNFCCC conference in Bonn a compromise was struck allowing carbonabsorbing forests to be used against emissions with the result that Canada may obtain more than 20 per cent of its target with such credits (MacKinnon 2001).