Wednesday, July 14, 2010

Pew Outback carbon study only half the story

A study by the Pew Environment Group understates the Australian countryside’s carbon storage by more than half. The study measured only carbon captured in plants and trees, overlooking soils which can hold three times as much carbon as vegetation. The Pew Study says vegetation could possibly contain an extra 1.3 billion tonnes of carbon by 2050. Australian scientists have said the soil can sequester nearly a billion tonnes of CO2 each year.
NASA estimates that the world’s soils hold 1500 gigatonnes of carbon while the world’s vegetation holds less than 800 gigatonnes.
The Pew website describes its study as "An assessment of carbon storage, sequestration and greenhouse gas emissions in remote Australia."
Why would the Pew study ignore soils if it wanted to demonstrate the carbon capture capability of our farmlands and rangelands? It is very pointed. Green groups cannot get their heads around anything that isn’t forests and native vegetation. Carbon Farming includes protecting native vegetation and reforestry. The Pew study report hides the exclusion of soil carbon in a footnote. This suspicion of farmers and the ideological belief that they should not be rewarded for changing to more conservationist farming practices because ‘they should be doing it anyway’.

Potential soil carbon sequestration tonnages: various estimations

256 million tonnes of carbon dioxide per year – rangelands only
(Baker, B, Barnett, G., and Howden, M. “Carbon Sequestration in Australia’s Rangelands” CRC for Greenhouse Accounting, Canberra, 2000)

596 million tonnes of carbon dioxide per year - rangelands, cropping soils (Garnaut Climate Change Review 2008)

928 million tonnes of carbon dioxide per year – rangelands only
(Grace, Peter, Carbon Models and Rangelands, Carbon Farming Conference, 2008)

946 million tonnes carbon dioxide per annum – rangelands, cropping soils (Dr Christine Jones, Pers. Comm, Garnaut Enquiry, 2008)

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