World Environment Day Report: Carbon Capture and Storage Nature's Way

Celebrated each year on June 5, World Environment Day's global hosts this year are the Government and people of Mexico.

Mexico City from Chapultepec Forest (Photo by Chilly Casey)

UNEP Executive Director Achim Steiner said, "Tens of billions of dollars are being earmarked for carbon capture and storage at power stations with the CO2 to be buried underground or under the sea."

"But perhaps the international community is overlooking a tried and tested method that has been working for millennia, the biosphere," he said. "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."

"This is also in line with UNEP's Green Economy initiative as for the same dollar, euro, peso or yuan not only are we combating climate change, but potentially delivering 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," Steiner said.

UNEP's Rapid Assessment report "The Natural Fix? The Role of Ecosystems in Climate Mitigation" comes just under six months before the crucial UN climate convention meeting in Copenhagen, Denmark, where governments are expected to write a successor agreement to the Kyoto Protocol, which expires in 2012.

The report concludes that the adoption of a comprehensive policy framework under the UN Framework Convention on Climate Change for addressing ecosystem carbon management would be "a very significant advance."

It is vital to manage carbon in biological systems, to safeguard existing stores of carbon, reduce emissions and to maximize the potential of natural and agricultural areas for removing carbon from the atmosphere.

Farmer Hadji Khan works the dryland Kovak Valley, Balochistan. He holds two types of the herb artemisia, or wormwood. (Photo courtesy ICARDA)

Drylands, in particular, offer opportunities for combining carbon management and land restoration say Barney Dickson and Kate Trumper of the UNEP-World Conservation Monitoring Centre, who spearheaded the compilation of the report in collaboration with 20 experts.

"While more research will be needed to fully capture the carbon and livelihood opportunities from drylands, it is already clear that there is a potentially a big bang for your carbon buck," they said. "Their large area means that total carbon potential is high and the often degraded soils means extra carbon could boost agricultural productivity and incomes in some of the poorest parts of the world."

Tropical forests hold the largest terrestrial carbon store with an annual global uptake of around 1.3 Gt of carbon, or about 15 percent of the total carbon emissions resulting from human activities.

Global tropical deforestation rates are currently estimated to be as high as 14.8 million hectares per year - about the size of Bangladesh, while deforestation is responsible for nearly one-fifth of the global greenhouse gas emissions - more than the entire transport sector.

Clearing of tropical forests may release an additional 87 to 130 Gt by 2100, corresponding to the carbon release of more than a decade of global fossil fuel combustion at current rates.

Reducing deforestation rates by 50 percent by 2050 and then maintaining them at this level until 2100 would avoid the direct release of up to 50Gt of carbon this century.

Conventional logging techniques damage or kill a substantial part of the remaining vegetation during harvesting, resulting in large carbon losses.

Improved logging techniques can further reduce carbon losses by around 30 percent compared to conventional logging techniques.

Temperate forests in Europe and North America have been expanding over recent years - they are estimated to be capturing and storing between seven and 12 percent of Europe's emissions. Further reforestation and management could enhance this rate.

Trees are grown with maize on an agroforestry field in Kenya. (Photo courtesy World Agroforestry Center)

Agriculture could be climate neutral by 2030, the report finds. The agricultural sector has the largest readily achievable gains in carbon storage if best management practices, such as avoiding turning over the soil and using natural nutrients like compost and manure, were widely adopted.

Agroforestry - where food production is combined with tree planting - has a particularly high potential for carbon sequestration in tropical areas.

Although peatlands cover only a tiny percentage of the Earth's surface they are, metre for metre, the most effective carbon stores of all ecosystems, the report shows.

Overall draining of tropical peatlands, mainly for palm oil and pulpwood production, leads to annual carbon losses of up to 0.8 Gt per year. Peat fires in Southeast Asia are responsible for half of these emissions.

If carbon emissions were valued at US$100 of CO2 equivalent, in 2030 the agricultural sector would be second only to building as potentially the most important sector for achieving carbon cuts.

At this level of carbon pricing, forestry and agriculture combined would be more important than any other single sector, and would retain high importance at even lower carbon prices.

Yet now, international climate regime only partly addresses emissions from land-use change, such as deforestation, and does not provide incentives for reducing carbon emissions from forests and other ecosystems, let alone for conserving them as carbon sinks.

Tropical forest in Malaysia (Photo by Mahdi Ayat)

It is expected that governments negotiating the new climate agreement in Copenhagen in December this year will take the first step in this direction by starting to pay developing countries for reducing emissions from deforestation and forest degradation.

The cost of ecosystem carbon management can be very low compared to other clean energy options, the report states. Managing grazing, fertilizers and fire on grasslands to reduce emissions costs as little as US$5 per tonne of carbon dioxide equivalent per year.

Restoration of soils and degraded land cost about US$10 per tonne, while the costs of technological carbon capture and storage are estimated at US$20-270 per tonne of carbon dioxide equivalent.

The economic mitigation potential of forestry would double if carbon prices increased from US$20 per tonne of carbon dioxide equivalent to US$100 per tonne.

The report suggests that a more comprehensive system of payments for ecosystem services should be considered.

"Our planet's living systems have developed ingenious, efficient and cost-effective ways to manage carbon. 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," the report says.

UNEP and partners, with funding from the Global Environment Facility, have launched a new project among communities in Western Kenya, Niger, Nigeria and China, to assess with greater precision the amount of carbon locked away in different ecosystems and landscapes under a variety of management regimes.

The findings, leading to a global standard upon which carbon investment decisions can be taken, should be available in 18 months.

Copyright Environment News Service (ENS) 2009. All rights reserved.