Earth Talk: Peat bogs – ecosystems that store C02
Q: Is it true that the loss of the world’s peatlands is a major factor in the buildup of greenhouse gases in the atmosphere? If so, what can be done about it?
– Larissa S., Las Vegas
A: Peatlands are wetland ecosystems that accumulate plant material to form layers of peat soil up to 60 feet thick. They can store, on average, 10 times more carbon dioxide (CO2), the leading greenhouse gas, than other ecosystems. As such, the world’s peat bogs represent an important “carbon sink,” a place where CO2 is stored below ground and can’t escape into the atmosphere and exacerbate global warming. When drained or burned, however, peat decomposes and the stored carbon gets released into the atmosphere.
A 2007 United Nations Environment Program (UNEP) study of the role peatlands play in human-induced climate change found that the world’s estimated 988 million acres of peat (which represent about 3 percent of the world’s land and freshwater surface) are capable of storing some 2 trillion tons of CO2 – equivalent to about 100 years’ worth of fossil- fuel emissions. Because of this, many scientists say that the widespread conversion of peat bogs into commercial uses around the world is serious cause for alarm.
In Finland, Scotland, and Ireland, peat is harvested on an industrial scale for use in power stations and for heating, cooking, and use in domestic fireplaces.
But the problem is most urgent in countries such as Indonesia and Malaysia, where economic hardships force people to drain peatlands to create farms and plantations.
Wetlands International estimates that CO2 emissions from drained or burned Indonesian peatlands total some 2 billion tons annually, equal to about 10 percent of the emissions resulting from burning coal, oil, and natural gas. Similar amounts of CO2 are probably coming out of Malaysian peatlands.
The problem has worsened in recent years as surging global demand for timber, pulp, and biofuel speeds up the conversion of peatlands to intensively managed tree farms and palm-oil plantations.
Protection of peatlands may actually be one of the least costly ways to mitigate global warming, says Marcel Silvius of Wetlands International, as it would cost less than 7 cents (US) per ton of avoided CO2.
Just like a global phaseout of old, energy-guzzling light bulbs or a switch to hybrid cars,” says UNEP head Achim Steiner, “protecting and restoring peatlands is perhaps another key ‘low hanging fruit’ and among the most cost-effective options for climate change mitigation.”
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