Dead planet, living planet

have emitted 78 GtC to the atmosphere between 1850–1998 (Lal, 2004). Restoring degraded soils enhances soil carbon se- questration and promotes biomass growth (Lal, 2008). SOC content can recover over time with restoration of degraded soil through revegetation and good management practices (Lal, 2004; 2008). For example, dryland restoration could bring global carbon sequestration in arid ecosystems up to 0.8–1.9 GtC per year (Keller and Goldstein, 1998; Lal, 2009). Wetlands and peatlands are rich in carbon. Peatlands, although forming only 3% of the world’s land surface, contain 30% of all global soil carbon (Parish et al ., 2008). Large areas of wetland and peatland have been drained or disturbed, releasing CO 2 into the atmosphere. Restoration could reverse this process and prove to be a low-cost greenhouse gas mitigation strategy (IPCC, 2007), though restoration of very degraded areas can be a slow process (Lal, 2008). A successful forest peatland restoration project in Indonesia restored approximately 60000 ha of peatland, reduc-

ing emissions from the degraded peat of about 1.15 GtC per year (Society for Ecological Restoration International, 2009), and enhancing sequestration. Restoration of wetlands can therefore increase carbon storage as well as maintaining other climate reg- ulation services. At a global scale, CO 2 emission from peatland drainage in Southeast Asia is contributing the equivalent of 1.3% to 3.1% of current global CO 2 emissions from the combustion of fossil fuel (Hooijer et al ., 2010) Restoring wetland, watershed and river ecosystems also indirect- ly contributes to climate change mitigation by protecting coastal vegetation and the ocean from excessive sediment and nutrient flows. Protecting, improving management and restoring coastal and marine carbon sinks (blue carbon) would prevent the release of up to 0.45 GtC per year (Nellemann et al . 2009).

Vegetated coastal habitats, such as mangroves, salt marshes and sea grass meadows, sequester carbon in their biomass and

Uptake of carbon dioxide from the atmosphere Gigatonnes of carbon per year

0.150

Arctic Ocean

0.125

Recent studies

0.100

Past studies

Barents Sea

0.075

Chukchi Sea

Central Basin Canadian Archipelago

0.050

East Siberian Sea

Kara Sea

0.025

Laptev Sea

Beaufort Sea

In Costa Rica, a mixed-species reforestation carbon offset project is estimated to absorb 24 tonnes of CO 2 every year for each ha of planted forest for 25 years. Tree planting © Reforest the Tropics http://reforestthetropics.org/

0

Source : Sommerkorn and Hassol, 2009.

Figure 12: Blue carbon: Uptake of CO 2 wide (Sommerkorn and Hassol 2009).

in different oceans world-

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