Radical Noesis - Thinking outside the box

The article focuses on British airline travel, but the implications go far beyond Britain. British airline emissions of carbon dioxide increased from 4.6 million tons in 1990 to 8.8 million tons in 2000. Utilizing government predictions, that level will rise to 17.7 million tons by 2030. These increases reflect the expanding popularity of airline travel, and the effort to bring (or keep) ticket prices low enough for mass transportation by plane.

A number of initiatives (primarily in Europe, and in North America) have been aimed at reducing various chemical emissions - nitrous oxide, carbon dioxide, etc. These have resulted in placing controls on polluting industries and on automobile emissions. However, these are ground based pollution sources. Airplanes, jets, and rockets release their emissions directly into the stratosphere where atmospheric ozone resides. It is logical that those emissions might have a significant impact on ozone depletion. The Independent article states that emissions directly into the stratosphere have 2.7 times the impact on the ozone layer as ground based emissions. This magnifies the problem of expanding airline transportation dramatically.

The article includes some interesting facts about the impacts of flying:

The facts about flying

* Air travel produces 19 times the greenhouse gas emissions of trains; and 190 times that of a ship.

* Aviation could contribute 15 per cent of greenhouse gases each year if unchecked.

* Greenhouse gas emissions caused by UK air travel have doubled in the past 13 years, from 20.1m tons in 1990 to 39.5m tons in 2004.

* During the same period emissions from UK cars rose by 8m tons, to 67.8m tons.

* One return flight to Florida produces the equivalent CO2 of a year's average motoring.

* Emissions at altitude have 2.7 times the environmental impact of those on the ground.

* Air travel is growing at UK airports at an average of 4.25 per cent. In 1970, 32 million flew from UK airports; in 2002, 189 million. By 2030 some 500 million passengers may pass through UK airports.

* Cargo transportation is growing by 7 per cent a year. In 1970, 580,000 tons of freight were moved by plane; in 2002, 2.2 million tons. It is forecast to reach 5 million tons in 2010.

* 50 per cent of the UK population flew at least once in 2001.

* Flying 1kg of asparagus from California to the UK uses 900 times more energy than the home-grown equivalent.

In searching around for other information about ozone depletion I found some good references that explain how the process works. I have included them as resources at the end of this article. Some of them are pretty technical, but still decipherable. Basically, ozone is produced (and destroyed) through chemical and phytochemical (light stimulated) processes. Changing the mixture and balance of chemicals in the stratosphere dramatically changes the chemical reactions which results in dramatic acceleration of destruction of atmospheric ozone. Many of the chemicals that are reaching the stratosphere have lifetimes ranging from 50 to 300 years (or so). That means they will continue to impact the chemical cycle for that long. Some substances such as chlorine and bromine are incredibly destructive in that they destroy ozone at an atom for atom rate in the hundreds to thousands on times.

Most of what we hear of the problems that loss of the ozone layer cause is skin cancer and blindness. However, it dramatically effects plant life dependent upon photosynthesis. It also, decreases the effectiveness of the immune system (which is a new piece of information for me).

In the United States, the major airlines have been struggling for years. The combination of the use of airplanes in the September 11, 2001 events, and the cost of fuel have only exacerbated an already deteriorating situation. New, shorter hop, economy airlines have moved in a cost competitors to the large companies. However, whether you have large aircraft or smaller ones plying the sky they are still emitting their exhaust into the stratosphere with potentially catastrophic effect.

Resources
Union of Concerned Scientists, The Science of Stratospheric Ozone Depletion

Ozone Depletion FAQ Part II: Stratospheric Chlorine and Bromine

From The Center for Coastal Physical Oceanography Studying Earth's Environment From Space see the Strastosoheric Ozone Section