4.1 Overview
Greenhouse gases have played an important role in maintaining a hospitable climate on earth. It is estimated that, without their reflection of heat back to its surface, the earth would have been approximately 60oF cooler. Now, however, there is concern that the buildup of these gases in the atmosphere will cause reflected heat to increase global temperatures, with negative impacts on human life and activity.
Water vapour is the gas with the largest greenhouse effect but its atmospheric concentration is not directly affected on a global scale by human activities. The other major greenhouse gases are carbon dioxide (CO2), methane, nitrous oxide, and most halogenated substances, such as chlorofluorocarbons (CFCs).
The current focus at this time is on atmospheric concentrations of CO2, which has a lifetime of between 50 and 500 years and is estimated to contribute to well over one half of the anticipated global warming.
As the global climate warms, a portion of the heating will go into evaporating larger quantities of water from the earth's surface. The warmer atmosphere can retain more water, creating circumstances which may lead to extreme precipitation events. However, the warming phenomenon can also cause droughts in areas not conducive to rain and snow, as the warmer environment will dry soils in such areas to a greater extent.
Since 1988, when a scorching summer thrust the "greenhouse effect" onto front pages, billions have been invested in climate research, including the development of computer models to predict and project climate change.
There are still major uncertainties about the magnitude of global warming and the role of anthropogenic emissions in it. However, some scientists believe that the temperature increase in the last century was likely the largest in 10,000 years, and coincides with a significant increase in CO2 as result of fossil fuel combustion.
While concluding that the one-degree Fahrenheit temperature increase over the last century is at least partly the result of human fossil fuel burning, the Intergovernmental Panel on Climate Change (IPCC) also scaled back the predicted temperature increase by a third, to a "best" estimate of 3.6oF by the year 2100 if emissions remain uncurbed. Forecasts of the rise in sea-level caused by melting ice and warming oceans, have also been reduced by 25 percent.
However, researchers suggest that higher temperatures will not be distributed evenly, bringing a greater risk of regional drought or coastal storms.(1)
A contrasting temperature record suggests the planet hasn't warmed, at least since 1979. The University of Alabama's Earth System Science Laboratory notes that satellites have detected a faint cooling in that time; however, other weather factors could be masking a broader warming trend.
Finding
Nitrogen oxides (NOX) and CO2 are associated with transportation (as is VOC (volatile organic compounds) production) and electrical energy generation (particularly coal fired) sectors. Further reductions in emissions from these two sectors appear necessary during the next decade if ecosystem damage is to be curtailed and ecosystem quality preserved and sustained.
4.2 Control Scenarios
Many experts say that even the most ambitious and marginally feasible program will not be adequate to halt the increase in concentrations of carbon dioxide in the atmosphere, which is believed to be a major factor in the temperature increases.
Because carbon dioxide lingers for years after it is released, the IPCC notes that world releases must ultimately be cut in half to stop the buildup; this will require a fundamental shift in energy generation away from the direct combustion of coal and oil.
Environmentalists seek a commitment of a 10 percent reduction in U.S. emissions by the year 2010. Reductions could be achieved through encouraging use of wind, solar and other non-combustion power sources and increasing the fuel efficiency of new cars. The Intergovernmental Panel on Climate Change estimates that world greenhouse emissions can be cut by 10 to 20 percent through policies that actually assist the economy over the long term, such as better insulation to reduce energy consumption. Small-island states, most threatened by sea-level rise, want a 20 percent reduction by 2005.
In 1993, the Clinton Administration announced a Climate Change Action Plan, focused on three major sectors; transportation, industrial and residential/commercial. Major responsibilities were given to the Department of Energy, who has elicited Accords with over 600 utilities (two-thirds of the electric power generation capacity). The reduction mechanisms in these Accords exhibit flexibility and include assuming credit for emission reductions or preservation of greenhouse gas sinks, such as forests, outside the United States. Major reductions are envisaged, in order of increasing magnitude, through:
However, total carbon dioxide emissions from the United States increased by 5.5 percent from 1990 to 1995. Current projections show a 28% increase in greenhouse gas emissions by 2010. Energy deregulation (Federal Environmental Regulation Commission (FERC)) is viewed as possibly increasing demand and also emissions beyond this estimate. Further controls under the Clean Air Act to reduce emissions of NOX, sulphur dioxide, and particulate matter should lower these projections.
Recognizing that the 1993 voluntary targets on energy reduction have not altered America's position as the largest global emitter of greenhouse gases, Administration officials are now promoting legally binding limits on greenhouse gas releases. As a result, the United States will be advocating an international agreement by December of this year that would require industrialized nations to control greenhouse emissions to a particular defined level. Limits will follow for those developing nations that may account for the majority of carbon emissions late in the 21st century.
The U. S. proposal would cap each country's emissions, but allow flexibility in meeting that cap including, for instance, reducing carbon dioxide releases in another country. As a result, the United States could meet its reduction goals by promoting energy efficiency in fast-growing China, which currently burns large amounts of coal.(2)
While Canada produces only about 2% of the gases that contribute to warming, production of carbon dioxide has increased 6% since 1990 and may increase to 12% by the year 2000. Canada's commitment at the Rio Summit in 1992 was to curtail CO2 production to 1990 levels. There is concern that a 1995 voluntary plan involving 600 companies and public organizations responsible for more than half of Canada's emissions is inadequate to achieve the established target.
Unfortunately CO2 emissions are expected to increase into the next century. By 2010, they are expected to be 19% above the current target; 36% by 2020, if significant and timely action is not taken to reduce greenhouse emissions.
The Canadian government also recognizes that emissions from the transportation sector must be further curtailed. The Transportation and Climate Change Collaborative has recommended full cost transportation pricing. It is anticipated that the Task Force on Cleaner Vehicle and Fuel will result in new standards for less polluting gasoline and diesel fuel and initiate a new program for low-emission vehicles by 2001.
4.2.1 The International Management Mechanism
At the 1992 Earth Summit in Rio, the leaders of 154 nations, including Canada and the United States, signed the United Nations Framework Convention on Climate Change, with the objective of "stabilizing greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system." The desired concentrations are not stipulated. The framework further commits the developed countries (or Annex 1 Parties) to take the lead by limiting anthropogenic emissions of greenhouse gases (using 1990 as a base year) and protecting and enhancing greenhouse gas sinks and reservoirs (such as forests).
Since the Earth Summit, the United Nations has established an office for the Framework Convention on Climate Change in Bonn, Germany and the Conference of Parties (COP) has met in Berlin in 1995, Geneva in June 1996 and will next meet in Japan in December. To date, only Britain, with the increased use of natural gas for power generation, and Germany, the Soviet Union and its former satellite nations in Eastern Europe (largely due to wholesale restructuring and modernization of their economies) appear to be in a position to meet their reduction commitments.(3)
Most recently, the United States has called for ongoing negotiations to set realistic, verifiable, and binding medium term emission targets, while moving forward on a longer-term goals. Such limits are to be discussed at the December meeting in Japan.
FINDING:
Concerns over global warming and associated current and projected increases in carbon dioxide emissions are an additional impetus to the development of further controls and alternatives in power generation and consumption, including that used for transportation.
RECOMMENDATION:
Recognizing the additional benefits to be achieved in other areas, the Commission advocates and promotes further control and change in the industrial, transportation and commercial/residential sectors required to reduce, in the short term, emissions of carbon dioxide and further research to identify a long term strategy for reducing these emissions.
1. "Global Climate Change: an Overview of the U.S. and International Efforts to Reduce Greenhouse Gas Emissions," Dr. C.V. Mathai, EM Magazine, Air and Waste Management Association, February 1997, pgs. 25 to 33 March 3, 1997. Copyright (c) 1997 N.Y. Times News Service
2. Environmental News Service - http://www.envirolink.org/environews/ens/
3. Report of Canada to the United National Commission on Sustainable Development - Fourth Session of the Commission, April 18 to May 3, 1996.