Saturday, February 25, 2006

Soil Carbon Fact Sheet

• Carbon is the element that bears most responsibility for global warming, in the form of CO2.

• Carbon was stored (sequestered) underground in oil and coal reserves for millions of years until they were chosen as the major energy sources for modern society. Burning these carbon sinks released carbon into the atmosphere in the form of CO2.

• Governments are requiring of organizations whose activities cause greenhouse gases to be emitted to invest in carbon sinks by buying carbon ‘credits’. This market has been estimated to grow to $100bn by 2010 (Deutsche Bank) and $120bn by 2012 (Rothschild Bank Australia).

• Degraded soils can store up to 5 times more organic carbon in their surface layers that they currently hold if the soil management approach changes.

• The cheapest, most efficient and most beneficial form of organic carbon for spoil life is exudation from actively growing roots of pasture grasses and cereals.

• Soil carbon levels can be increased by adopting foms of ecological agriculture such as biodynamic, organic and biological farming. Practices include cover crops, green manures, mulches, fish and seaweed products, manures, recycled green waste, biosolids, composts, compost teas, humic substances and microbial stimulants.

• Conventional forest management causes net carbon losses due to lack of ground cover underneath, (Bare ground is a source of atmospheric carbon dioxide.)

• Natural rainforest is a net contributor to greenhouse gases because decaying trees and vegetation release methane and CO2.

• The world’s soils hold around twice as much carbon as the atmosphere and three times as much carbon as vegetation. Soil represents the largest carbon sink over which we have control.

• The terrestrial biosphere currently sequesters 2 billion metric tons of carbon annually. (US Department of Agriculture)

• Soils contain 82% of terrestrial carbon.

• "Enhancing the natural processes that remove CO2 from the atmosphere is thought to be the most cost-effective means of reducing atmospheric levels of CO2." (US Department of Energy)

• "Soil organic carbon is the largest reservoir in interaction with the atmosphere." (United Nations Food & Agriculture Organisation) - Vegetation 650 gigatons, atmosphere 750 gigatons, soil 1500 gigatons

• The carbon sink capacity of the world's agricultural and degraded soils is 50% to 66% of the historic carbon loss of 42 to 78 gigatons of carbon.

• Grazing land comprises more than half the total land surface

• An acre of pasture can sequester more carbon than an acre of forest.

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