Dear EarthTalk: What were the environmental impacts of the huge coal ash spill in Tennessee this past December?
Dear EarthTalk: Is it true that the loss of the world's peatlands is a major factor in the build-up of greenhouse gases in the atmosphere. If so, what can be done about it?
— Larissa S., Las Vegas, Nev.
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 Programme (UNEP) study of the role peatlands play in human-induced climate change found that the world's estimated 988 million acres of peatland (which represent about three percent of the world's land and freshwater surface) are capable of storing some two trillion tons of CO2 — equivalent to about 100 years worth of fossil fuel emissions.
As such, 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 like Indonesia and Malaysia, where economic hardships force people to drain peatlands to create farms and plantations. Marcel Silvius of the Dutch non-profit Wetlands International says that "annual peatland emissions from Southeast Asia far exceed fossil fuel contributions from major polluting countries." He adds that Indonesia, now ranked 21st in the world in greenhouse gas emissions, would move to third place (behind the U.S. and China) if peatland losses were factored in.
Wetlands International estimates that CO2 emissions from drained or burnt Indonesian peatlands alone total some two billion tons annually, equal to about 10 percent of the emissions resulting from burning coal, oil and natural gas. Similar amounts of CO2 are likely coming out of Malaysian peatlands as well.
The problem has worsened in recent years as surging global demand for timber, pulp and biofuel speeds up the conversion of otherwise-ignored peatlands to intensively managed tree farms and palm oil plantations. Silvius says that a ton of palm oil — Indonesia's top export and the key ingredient in biodiesel fuel — grown on drained peatlands emits 20 times more CO2 than a ton of gasoline. Yet, he says, protection of peatlands may actually be one of the least costly ways to mitigate global warming, as it would cost less than seven cents ($US) per ton of avoided CO2.
"Just like a global phase out 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." For its part, UNEP is stressing that countries should be allowed to count protecting peatlands as among their creditable efforts to reduce their carbon footprints as the world braces for global warming.
CONTACTS: UNEP, www.unep.org; Wetlands International, www.wetlands.org.
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