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 CO2 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-
Uptake of carbon dioxide from the atmosphere
Gigatonnes of carbon per year
0.150
Arctic Ocean
0.125 0.100 0.075 0.050 0.025
0
Source : Sommerkorn and Hassol, 2009.
Figure 12: Blue carbon: Uptake of CO2 in different oceans world- wide (Sommerkorn and Hassol 2009).
62
Past studies Recent studies
Barents Sea Chukchi Sea
Canadian Archipelago Central Basin
East Siberian Sea Kara Sea
Laptev Sea Beaufort Sea
In Costa Rica, a mixed-species reforestation carbon offset project
is estimated to absorb 24 tonnes of CO2 every year for each ha of planted forest for 25 years. Tree planting © Reforest the Tropics
http://reforestthetropics.org/
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, CO2 emission from peatland drainage in Southeast Asia is contributing the equivalent of 1.3%
to 3.1% of current global CO2 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
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112