Cross-Border, Nature Based Market Solutions to Protect Blue Carbon Coastal Ecosystems in the Californias

March 2022

mangroves can hold three times more carbon in their soil than other types of forests. 110 In fact, mangroves and salty scrubs in the Gulf of California jointly store 28% of the total belowground carbon pool in the entire region. 111 Consequently, destroying these coastal mangrove forests could lead to the release of large carbon stocks back into the atmosphere, resulting in increased CO 2 emissions 112, 113 and reduced carbon sequestration potential in the future. Valuing carbon stocks in a particular area can then be thought of as the value of carbon that is lost when deforestation occurs in that area. As highlighted in detail in Table 5 in the Appendix, Bahia Magdalena holds the most important mangrove forest in the Baja California peninsula. There, deforestation rates and carbon stocks of Mexican mangroves were estimated to predict a social cost of carbon 114 of US $392 (± 7.4) million over 25 years of continued deforestation. The carbon stock values of Mexican mangroves were compared to potential investment and costs of conservation and it was found that when considering the value of carbon stocks alone, the average value of a hectare of Mexican mangrove was US $38,100 (± 4,300), while the cost of investment was between US $44.7 and US $182.5 per hectare. Magdalena Bay, Mexico. J Atmos Ocean Tech 30, 1266– 1294 (2013). 110 Donato, D. C. et al. Mangroves among the most carbon-rich forests in the tropics. Nat Geosci 4, 293 (2011). 111 Ezcurra, P., Ezcurra, E., Garcillán, P. P., Costa, M. T. & Aburto-Oropeza, O. Coastal landforms and accumulation of mangrove peat increase carbon sequestration and storage. Proc National Acad Sci 113, 4404–4409 (2016). 112 Kauffman, J. B., Trejo, H. H., Garcia, M. del C. J., Heider, C. & Contreras, W. M. Carbon stocks of mangroves and losses arising from their conversion to These results indicate that society could save on average between US $10,800 and US $31,900 in

avoided damages per hectare for every municipio by protecting mangrove forests over the next 25 years. On a per-hectare basis, the cost of investment to protect mangroves was far less than the carbon stock value, and this is not even including the value of all other ecosystem services beyond carbon sequestration. For those wetlands along the Pacific coast of the Peninsula, mangroves play a critical role in the maintenance of fish stocks. In particular, Magdalena Bay is the most important fishing ground in the state, and part of that productivity relies on the mangrove forests found on that wetland. The significant value of Mexico’s blue carbon ecosystems, in particular in the case of Bahia Magdalena, incentivizes future conservation efforts both domestically and internationally. That said, it is important to emphasize that, due to climate change, there will be important changes in the relative extent and value of Baja California peninsula’s blue carbon inventory over time— particularly due to sea level rise. Furthermore, the expected impact of climate change on mangrove coverage in that lagoon complex over time will also impact the future potential for monetizing the sale of carbon credits in any voluntary or future compliance market. After all, as stated before, over the ten-year period from 2001 to 2010, Bahia Magdalena’s mangrove inventory declined already from 25,730 ha (25,730 acres) to 22,312 ha (55,134.2 acres). 115 cattle pastures in the Pantanos de Centla, Mexico. Wetl Ecol Manag 24, 203–216 (2016). 113 Adame, M. F. et al. The undervalued contribution of mangrove protection in Mexico to carbon emission targets. Conserv Lett 11, e12445 (2018). 114 The SCC reflects the economic cost of an incremental unit of CO 2 , meaning it represents what society is willing to pay today to avoid the future damages or costs caused by an additional ton of carbon emissions. 115 http://www.conabio.gob.mx/conocimiento/manglares/ doctos/caracterizacion/PN03_Bahia_Magdalena_cara cterizacion.pdf

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