The first of the problems is the price of reforestation carbon credits which is primarily determined by the quantity of carbon per hectare that can be sequestered over a set number of years. If mangroves and peat forests have up to three times more carbon per hectare, why is their reforestation price not proportionately lower than for other forest types that store less carbon? Mangroves are unusual in that a huge amount of their total carbon is locked away in the deep sediment underneath the trees, rather than in the trees themselves. The answer therefore lies in the methodologies used by carbon certification schemes such as the Clean Development Mechanism (CDM) for mangroves which currently allow only 0.5 tonnes per hectare per year in carbon accumulation in the sediment. Yet numerous academic studies have shown that replanted mangroves after only 25 – 40 years have sediment carbon loads of >600 tonnes per hectare which the CDM would expect to take 1200 years to accumulate! In other words, current approaches are massively underestimating the amount of carbon built up in the sediment within reforested mangroves, which is hugely inflating the price per ton of carbon.
The Wallacea Trust together with Operation Wallacea are proposing a new carbon accounting methodology under the Plan Vivo certification scheme, that more closely aligns with observed levels of carbon accumulation in mangrove sediment and which should then enable mangrove carbon credit prices to be in the $5 – $7 range which would really drive reforestation investment. The cheapest carbon credits for reforestation of natural forest are around $15, and the cheapest agroforestry schemes credits are around $12. This is why when multinationals are faced with buying say 2 million credits a year they currently tend to prefer renewable energy credits which are in the $5 range. The price difference is so great between the two options that most multinationals buy the bulk of their credits at the cheap end (renewables) and may do some small investments in the more expensive reforestation (usually agroforestry schemes).
The second reason is that there is a supply side problem of approved reforestation schemes because in many countries the mangroves are mainly owned by governments and getting them to issue carbon credits for these areas is fraught with difficulties. Countries quite rightly want to protect their existing forests so they can include them in their Nationally Determined Contributions (NDC) under the Paris Accord. Indonesia for example has a Paris Accord target of reducing GHG emissions under their own efforts by 29% by 2030. Part of this target is to protect and expand their Nationally Determined Contributions (NDC) of carbon sequestration in forests. They also have a target of an additional 12% reduction by 2030 with help from grant aid or private sector investment. Approval of private sector carbon credit schemes is a major blockage to the development of such schemes in Indonesia with many companies simply refusing to support carbon schemes in Indonesia because of these problems. Obviously, the Indonesians want to protect their NDC storage, but this could be boosted by private sector investment in reforesting currently deforested areas which have no carbon sequestration benefit to the NDC, and which are funded by the private sector with say 10% of the issued credits being released from each scheme to the Indonesian NDC free of charge. This would increase the overall size of the NDC and also provide substantial incoming investment to help reforest their lost mangroves.
The Wallacea Trust together with Operation Wallacea is developing test cases in Indonesia and Honduras that are being taken taking through the first stage of certification to enable around 2 million carbon credits to be available in the $5 – $7 price range (the final price depends primarily on govt taxes). However, more importantly, these schemes would be the first such examples of mangrove reforestation at an affordable price. According to Jakovac et al (2020) from 2002 – 2017, the world lost 154,220ha of mangroves which will have resulted in emissions of 320 million tonnes of carbon dioxide. Those same areas could be reforested for $1.5 billion which is a tiny fraction of the total carbon credit market called for by Mark Carney, Chief UN Envoy on Climate Change.
The Wallacea Trust are looking for corporate partners to help with developing these cost effective mangrove reforestation schemes. If you are interested please contact Dr Tim Coles (firstname.lastname@example.org) for further information.