Blue Carbon Financing of Mangrove Conservation in the Abidjan Convention Region: A Feasibility Study

3.2 Analysis of blue carbon stocks inWest, Central and Southern Africa

Size and distribution of blue carbon stocks in West, Central and Southern Africa Figure 6 illustrates the distribution of blue carbon environments, from the southern boundary of Mauritania to the northern boundary of Angola. In terms of the size of its blue carbon stocks, West, Central and Southern Africa contains approximately 14 per cent of the world’s mangrove area (Corcoran, Ravilious et al., 2007), with the region’s most extensive mangroves located in Nigeria, Guinea, Guinea-Bissau, Cameroon and Gabon (see Table 7, chapter 1). Nonetheless, mangroves in the region are believed to be in decline, with average estimates suggesting some 25 per cent loss in the region between 1980 and 2006 (Corcoran, Ravilious et al., 2007). The first ever workshop on mangroves inWest, Central and Southern Africa, held in Elmina, Ghana on 18-22 May 2014 put the average annual rate of blue carbon sink loss at 2-7 per cent (USAID, FCMC et al., 2014).

terms of the actual data sets available for mangrove coverage and carbon, the following (and in some cases overlapping) sources have been identified for reference: • Corcoran, Ravilious et al. 2007 This report presents coarse estimates of mangrove coverage from a variety of sources, including FAO and data that would also be subsequently used by Spalding, Kainuma et al. (2010). Since different estimation methods are used for different years, data within the report cannot be used in analyses to determine loss rates over time. • Spalding, Kainuma et al. 2010 This mangrove coverage data set was also presented in Corcoran, Ravilious et al. (2007) and is assembled from various sources, mainly for the years 1999-2003. • Giri, Ochieng et al. 2011 This is the most comprehensive global data set, estimating mangrove coverage using data mainly from 2000, at a relatively high resolution (30 m). Updates to this data set are forthcoming, but were not available at the time of preparing this report. The Giri et al. (2011) data set compared very well with the Fatoyinbo et al. (2013) data set, with Fatoyinbo et al. (2013) estimates being

Quantifying mangrove and blue carbon loss has been difficult due to a lack of relevant comprehensive data sets. In

Figure 6: Distribution of blue carbon environments in West, Central and Southern Africa: mangroves, salt marshes, and seagrasses Sources: Mangrove coverage for 1999-2000 (Fatoyinbo and Simard, 2013); salt marsh coverage (Halpern, Walbridge et al. 2008); seagrass coverage (Green and Short, 2003; UNEP-WCMC and Short, 2005).

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