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A dirty business

发布时间:2019-03-08 04:18:02来源:未知点击:

By Fred Pearce LANDFILL sites could soon become environmental assets. Research from Wisconsin suggests that burying waste paper and wood permanently locks away large amounts of carbon that would otherwise escape into the atmosphere and speed up global warming. The US now says it wants to count landfills as “carbon sinks” under the 1997 Kyoto Protocol to curb greenhouse gas emissions. Ironically, this could lead to countries shovelling away as much carbon waste as they can in landfills—traditionally viewed as environmentally unsound—so they can burn more fossil fuels. National inventories of greenhouse gases already include the methane given off by organic materials rotting in landfills. However, Jessie Micales and Ken Skog of the US government’s Forest Products Laboratory in Madison, worked out that most of the carbon in wood products in landfills never actually rots. About 70 per cent of carbon from paper, and more than 97 per cent from wood, remains locked away under the ground. They calculated that landfills in the US lock up 28 million tonnes of carbon a year—equivalent to 2 per cent of annual US carbon emissions from burning fossil fuels (International Biodeterioration and Biodegradation, vol 39, p 145). The US government wants to include landfills alongside forests as carbon sinks to offset their emissions of carbon dioxide. This would make it easier for the country to meet its Kyoto target of cutting emissions by 7 per cent by 2010. The idea was suggested during a meeting of the UN’s Intergovernmental Panel on Climate Change (IPCC) in Geneva last week. The meeting was the start of a detailed IPCC inquiry into finding ways of measuring the complex interchanges of carbon between the land and air. One task will be to track the fate of carbon in timber all the way from the forest floor to paper mill or furniture factory to landfill. “The US position is that we want to treat the carbon cycle as comprehensively as possible. As a consequence, accounting for landfill is important,” says Bill Hohenstein, an expert on the issue at the US’s Environmental Protection Agency in Washington DC. Perversely from the viewpoint of many environmentalists, this could encourage countries to bury more of their waste in landfills. “It’s a load of rubbish,” says Tony Juniper, policy and campaigns director of Friends of the Earth in London. “You can see manufacturers using this as an argument for making more paper and recycling less.” He says if you examine emissions from the paper industry through paper’s life cycle, including forestry and manufacturing, the equation doesn’t look so good. The controversy could come to a head at an intergovernmental policy workshop to be held in the US, probably in May. The workshop will discuss the rules for extending national inventories of greenhouse gases to include the gases that growing forests take from the atmosphere and those that deforestation releases. A key debate will be how to account for forest products, such as paper, fibre and wood, that lock up carbon for long periods. Depending on how the rules are drawn up,