Jun 5, 2009
Managing ecosystem carbon offers cheap solution
Ecosystem-carbon management can be used to reduce carbon emissions at a very low cost compared with carbon capture and storage. That’s according to The Natural Fix? The Role of Ecosystems in Climate Mitigation, a report released by the UN Environment Programme (UNEP) today to mark World Environment Day.
According to the report, grassland management can reduce emissions for only $5 a ton compared with an estimated $20–70 for carbon-capture and storage systems.
“Tens of billions of dollars are being earmarked for carbon capture and storage at power stations, with the carbon dioxide to be buried underground or under the sea,” said Achim Steiner, UNEP executive director. “But perhaps the international community is overlooking a tried-and-tested method that has been working for millennia, the biosphere. By some estimates the Earth’s living systems might be capable of sequestering more than 50 Gigatonnes of carbon over the coming decades, with the right market signals.”
Steiner says this approach is also in line with UNEP’s Green Economy initiative because, for the same amount of cash, it not only combats climate change but also potentially delivers “additional economic, environmental and developmental benefits from improved water supplies, soil stabilization and reduced biodiversity losses alongside new kinds of green jobs in natural-resource management and conservation”.
The report reckons that managing land-use changes and carbon in ecosystems could tackle 15% of the roughly 10 Gigatonnes of carbon emitted by human activities each year. It highlights tropical forests, peatlands and agriculture as priority systems for carbon management.
Tropical-deforestation rates are currently as much as 14.8 million hectares a year (about the size of Bangladesh). Deforestation is responsible for nearly one-fifth of global greenhouse-gas emissions – more than the entire transport sector. Reducing deforestation rates by 50% by 2050 and then maintaining them at this level until 2100 would avoid the direct release of up to 50 Gigatonnes of carbon this century. And improved logging techniques, which damage or kill less of the remaining vegetation than conventional methods, could reduce carbon losses by as much as a further 30%.
Peatland degradation, meanwhile, contributes up to 0.8 Gigatonnes of carbon a year – the report states that much of this could be avoided through restoration. While peatlands cover only a tiny percentage of the surface of the Earth they are, metre for metre, the most effective carbon stores of all of the ecosystems, storing an average of 1,450 ton of carbon a hectare. Around 65 million hectares of peatlands worldwide are considered degraded, with large quantities of carbon lost as a result of drainage. The re-wetting of peatlands and replanting of forests in areas that have been deforested could significantly reduce future greenhouse-gas emissions.
By adopting sustainable management practices, such as avoiding turning over the soil and using natural nutrients like compost and manure, the agricultural sector could be broadly carbon neutral by 2030, saving up to 2 Gigatonnes of carbon emissions. In fact, many of the agricultural practices that store more carbon can be implemented at little or no cost and 70% of this potential can be realized in developing countries.
While it is expected that governments negotiating the new climate agreement in Copenhagen in December will start to pay developing countries for reducing emissions from deforestation and forest degradation, the report argues that a more comprehensive system of payments for ecosystem services needs to be considered.
“Our planet’s living systems have developed ingenious, efficient and cost-effective ways to manage carbon,” reads the report. “Sending the right price signals to those who make economic and development choices about the value of preserving and effectively managing our forests, grasslands, peatlands and agricultural lands is critical for the success of any climate change mitigation strategies.”