Overview

Sulfer Dioxide is the principle gas along with nitrogen oxides (NOx), that participates in the formation of acid rain.

The lake trout above was captured from an acidified lake, showing clear indications of starvation due to its food source having disappeared. The bottom lake trout was captured from a previously acidified lake which was permitted to recover. Photo courtesy of Fisheries and Oceans Canada

Current annual emissions of sulfer dioxide amount to about 20 million tonnes in the US and about 2 million tonnes in Canada. Coal-fired thermal electric power plants produce about 70% of US emissions and about 20% of Canadian emissions. Nonferrous smelters, producing such metals as nickel and copper, account for about 50% of Canada's sulfer dioxide emissions. The three main issues caused by acid rain are:

1. it accelerates the weathering of naturally occuring rock structures, in particular, carbonate rocks [1] and accelerates the weathering of buildings, corroding of metals, in particular historical objects of artistic or cultural value such as statues and monuments,
    
2. it contributes to the increased acidity of lakes, rivers, streams and oceans, impacting the flora and fauna existing in these waters to their detriment such as the destruction of fish food sources,
    
3. it causes damages to flora such as trees and plants.

The principle contributor to the production of acid rain gases is the burning of fossil fuels such as coal-fired thermal electric power plants, factories, and vehicles. The by-products of burning fossil fuel are sulfer dioxide and oxides of nitrogen which when combined with moisture in the atmosphere return to the surface in the form of acid rain. This process is known as "deposition" and occurs when it rains or snows, but it can also occur when dust settles out of the atmosphere during dry periods.

Reduction of SO₂ through RETS deployment and conservation

Aside from the well documented conservation activities such as the reduction of the use of the automobile through public transit systems, numerous actions with respect to energy conservation in the home or business can facilitate the reduction of sulfer dioxide emissions, in particular, those emitted from coal-fired thermal electric power plants. The Ontario Ministry of Energy website offers numerous tips on helping consumers conserve energy and save money. Click on Tips to Help You Conserve Energy and Save Money.

Using generally available figures, the average Canadian home consumes 12,000KWh per year, the production of this energy using traditional fossil fuel sources will generate SO2 emissions on the order of:

12,000KWh * 0.012 lbs. = 144 lbs. SO₂

The deployment of RETS will reduce the user's dependency on the more traditional methods of electricity power production, and therefore, reduce the demand on the power plants which in turn may help to reduce the sulfuric oxide emissions. RETS can be considered as an individual's second and most significant step, next to energy conservation, in reducing the negative impact of human activity on our planet.

Footnotes

1. carbonate rocks are a class of sedimentary rock composed primarily of carbonate minerals, such as limestone, dolomite, chalk and tufa.

References

1. Brimblecombe, P. Air Composition and Chemistry. Cambridge University Press. 1996. ISBN 0-521-45366-6
2. Environment Canada. Canada-United States Air Quality Agreement. 2004.
3. Fisheries and Oceans Canada. Experimental Lakes Area - Protecting the Health of Canada's Lakes. 2005-05-02.
4. Government of Canada. "One Tonne-Challenge - Take Action on Climate Change". 2006-03-24.
5. The United Nations Framework Convention on Climate Change. "Kyoto Protocol". 16 February 2005.