Practical approaches to reducing greenhouse gas emissions have involved efforts to cut back on energy consumption (by reducing automobile usage, for example), as well as by increased efficiencies in things like building design, industrial processes and consumer products. Other approaches have included government and private sector efforts to develop alternatives to fossil fuels, including wave, solar, tidal and wind power generation.

Yet another approach has been to seek ways to prevent the emissions from existing fossil fuel energy production from entering the atmosphere through carbon capture and storage. This technology involves collecting carbon dioxide from locations like the oil sands or thermal power plants and storing it underground, often in depleted oil or gas formations or in coal bed reservoirs.  The challenge is to collect, pipe and inject carbon dioxide into the ground safely and at a reasonable cost. In a recent report, the United Nations Development program pointed out that, with rising oil and gas prices, "coal figures prominently in the present and planned energy mix of major emitters such as China, India and the United States. [Carbon capture and storage] is important because it holds out the promise of coal-fired power generation with near-zero emissions."   Despite initial small-scale success, however, carbon capture and storage has yet to be implemented on a large scale and it is unclear how much it would cost.

One of the problems, inevitably, is that high emission technologies have tended to be cheaper, or at least more convenient, than low emission ones. Much work has gone into finding ways to create appropriate and effective economic incentives to decrease emissions. These efforts draw on the ideas of American biologist Garrett Hardin, who in 1968 introduced the concept of "the tragedy of the commons" to explain pollution and other social and economic problems. Hardin described a pasture that is open to any cattle herdsman. The benefits of adding cattle to the commons accrue to the individual herdsman. However, because the cost of cattle grazing on the commons is shared equally by everyone, the herdsman does not consider the total costs. Hardin explained that "the rational herdsman concludes that the only sensible course for him to pursue is to add another animal to his herd. And another; and another...'' But this is the conclusion reached by each and every rational herdsman sharing a commons. Therein is the tragedy." Soon, the commons is over grazed and none of the cattle has enough to eat.   Another 20th century example that had a dramatic negative impact in Canada was over-fishing of ground fish, leading to the virtual extinction of the commercial cod fishery.

The 21st century "commons" is the earth's atmosphere and everyone who emits carbon dioxide into the atmosphere is a herdsman. The idea behind mechanisms like carbon taxes or carbon trading is to place an economic value on greenhouse gases, so that the people who emit them bear at least part of the real cost of climate change when they make their emission decisions. Last year, Quebec imposed a tax on gasoline and diesel while Alberta began charging large emitters $15 a tonne for emissions above certain levels.   In January, when this primer went to press, British Columbia's Finance Minister was musing publicly about introducing a carbon tax in that province, as well.   In Europe, meanwhile, carbon trading takes the form of a so-called cap and trade system, which imposes limits on carbon dioxide emissions for individual companies. Those firms that exceed the limit can buy the right to pollute from companies that emit below the cap.  How effective such systems are at reducing greenhouse gases depends in part on how low the cap (or how high the carbon tax) has been set. Canada's National Round Table on the Environment and the Economy, a federal advisory body, recently recommended that the Canadian government "institute a market-based policy that takes the form of an emission tax or a cap-and-trade system or a combination of the two."  

Carbon trading also happens between countries. Article 17 of the Kyoto protocol allows the developed countries that agreed to reduction targets to acquire reduction credits from each other.   Kyoto also allows developed countries to implement carbon dioxide reduction emissions and reforestation projects in other countries.   The Canadian government has been critical of international carbon emissions trading. Environment Minister John Baird has said that Canada refuses to purchase what he calls "hot air credits in Russia" to achieve Kyoto targets, arguing that the credits do not represent real climate change reductions and that buying credits is akin to pledging to lose weight and then "paying Russia to lose weight for us."  The argument is that it is impossible to verify whether or not the emission reductions have actually occurred.  Some environmentalists have insisted that legitimate carbon credits are available on the world market and that Canada could work with developing countries to create more credit opportunities (discussed below in approach #1).

On the political front, global efforts to combat climate change got underway at the so-called "Earth Summit" in Rio de Janeiro, Brazil, in 1992.  It took five more years to forge the Kyoto Protocol, which called on 38 industrialized and former Soviet bloc countries to reduce their greenhouse gas emissions to more than 5 % below 1990 levels by 2008 to 2012.  Some progress has been made. By 2004, according to a recent United Nations Development Programme (UNDP) report, those 38 countries had reduced their greenhouse gas emissions to 3 % below 1990 levels. However the report warns that emissions have been rising since 1999 and notes that much of the reduction was in the early 1990s--due in part to the economic crisis in the Russian Federation and other Eastern European countries after the collapse of the Soviet Union.  

An important new phenomenon in the global fight against climate change is the explosive economic growth in some developing countries. In 1990, the base year for calculating Kyoto emissions, developing countries were responsible for 30 % of global greenhouse gas emissions, according to the UNDP. Rapid industrialization in countries like India and China has changed that equation. By 2004, developing countries were responsible for 42 % of the 28,983 megatonnes of carbon dioxide emitted in the world.  

This is critical because the Kyoto Protocol only imposed binding emission reduction targets on developed and former Soviet Bloc countries. Indeed, much of the debate at last December's Bali conference focused on whether binding targets should be extended to developing countries. Critically, three of the top four emitters of carbon dioxide in the world in 2004 were not covered by the Kyoto agreement. The United States, the single most prolific emitter at 6,046 megatonnes, never ratified the deal. Meanwhile, as developing countries, China, the second highest emitter (5,007 Mt) and India (1,342 Mt) the fourth-highest emitter, were never covered by Kyoto. The third biggest emitter, the Russian Federation (1,524 Mt),   actually exceeded its emission reduction targets (however, as noted, that was due largely to the economic crisis that followed the collapse of the Soviet Union in the early 1990s ). Also, while China and India are among the top emitters of carbon dioxide, their per capita emissions are still much lower than those in most developed countries: Canadians emitted 20 tonnes of carbon dioxide per capita in 2004, compared to the 3.8 tonnes emitted per capita in China and just 1.2 tonnes in India.   

At Bali, the 190 developed and developing countries agreed on a "road map" to make deep emission cuts-and a two year deadline for further negotiations-but failed to set specific targets, according to the Globe and Mail. A side deal among the 38 developed countries already covered under the Kyoto Protocol called for them to cut emissions by 25 to 40 % by 2020.  (The details of that separate deal, which applies to Kyoto signatory Canada but not the United States, remain to be negotiated). While some bemoan what they see as limited gains at Bali, Canada's Environment Minister hailed the involvement of the United States in climate negotiations as "exciting."   

Meanwhile, within days of the Bali conference, the U.S. Congress passed an important new Energy Bill that will lead to a ban on incandescent light bulbs and require auto makers to substantially improve the fuel efficiency of cars and light trucks. (Under threat of a presidential veto, legislators dropped a provision that would have also raised taxes from oil companies to pay for alternative energy development).  Whether the energy bill, and the U.S. involvement in the Bali talks, foreshadow a more environmentally engaged America may well depend on the outcome of presidential elections later this year.

Next section: What has Canada done?