Heather Dolmage – Winter 2014
ESCI 302 – ENVIRONMENTAL ISSUE PRESENTATION
Desertification “Desertification is a fancy word for land that is turning to desert,” - Allan Savory What is desertification? •
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“…the diminution or destruction of the biological potential of the land that can lead ultimately to desert-like conditions.” – UNOCD, 1977 About 51 800 square km of fertile land is turned to desert annually. In the last 20 years, we have lost about the same amount of surface area as all of the farmland in the United States.
What causes desertification? •
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Over cultivation: “the excessive use of farmland to the point where productivity falls due to soil exhaustion or land degradation.” Source: http://geographyfieldwork.com/GeographyVocabularyGCSEFarming.htm Drought: bouts of unusually long periods with little to no rainfall (correlation/causation issues, ie. drought can be caused by desertification and vice versa) Overgrazing: When plants in an area cannot sustain the amount of animals feeding on them or there is not a sufficient recovery period for the plants. Happens both due to poor farming technique and in nature. Deforestation: “ Trees…help perpetuate the water cycle by returning water vapor back into the atmosphere. Without trees to fill these roles, many former forest lands can quickly become barren deserts.” http://environment.nationalgeographic.com/environment/global-warming/deforestation-overview/ Source: Desertification: Exploding the Myth by Davis S. G. Thomas and Nicholas J. Middleton
A Historical Example Close To Home! In the 1920s, North America entered a recession. To help cope, American farmers in the west overplowed and overgrazed their fields, which in the following years resulted in dozens of huge dust storms that could overtake whole cities! Ever heard of the Dirty ‘30s? Left behind was only desert. This era was called the Dust Bowl. Read more about it here: http://science.howstuffworks.com/environmental/c onservation/issues/desertification.htm
Why is it bad news? • •
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Worsens the lives of people in affected areas due to a lack of food, work, clean water, resources, and habitable ground From the World Health Organization, desertification causes the following: o higher threats of malnutrition from reduced food and water supplies; o more water- and food-borne diseases that result from poor hygiene and a lack of clean water; o respiratory diseases caused by atmospheric dust from wind erosion and other air pollutants; o the spread of infectious diseases as populations migrate. Climate Change: Less plants on the earth = more CO2 in the atmosphere. Damaged soil also contributes to added carbon in the atmosphere. Some believe it distributes more carbon into the atmosphere than fossil fuels. Huge economic loss due to uselessness of the land, in 1978 estimated a loss of $42 000 million per year. Sometimes driven by money focused industries such as forestry and agriculture which are resistant to change that may affect their profits.
Where is desertification happening? •
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Arid and semi-arid lands. Dry lands make up about 40% of the earth. About 10-20% has already been affected by Desertification. The brown sections of this map are all affected areas, most of which have been getting steadily worse for years.
How do we stop and reverse desertification? • • •
Agricultural techniques: not overplowing or over grazing land, mimicking what happens in nature. Reforestation: Planning trees where we cut them down. Controlled Grazing: see below.
Canada and desertification • •
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Industries like Oil, Forestry, and Agriculture are speeding up the process of already vulnerable areas, especially here in the prairies. Canada has also lost a huge number of grazing animals that historically would be found here, Bison for example, which disrupts the natural balance of our ecosystem. Canada is the only country of almost 195 to opt-out of the UN Convention to Combat Desertification. Harper stated that the convention is “too bureaucratic”.
Check out David Suzuki’s article on why Canada can’t afford to ignore desertification: http://www.davidsuzuki.org/blogs/sciencematters/2013/04/desertification-is-too-important-for-canada-to-ignore/
Controlled Grazing A recently discovered technique, by biologist Allan Savory, of increasing the number of livestock in a given area, and controlling their grazing patterns in a way that mimics nature’s patterns. As a result, the dung, urine, and mulch helps the earth be capable of retaining rainwater, reversing the effects of desertification. Watch Allan Savory’s TED Talk here: http://www.ted.com/talks/allan_savory_ how_to_green_the_world_s_deserts_an d_reverse_climate_change.html
