Low tech biochar production could be a highly effective nature-based solution for climate change mitigation in the developing world

Aim To compare the climate change mitigation benefits of nature-based solutions for management of municipal green waste with conventional management. Methods This study analyzed the carbon footprint of managing one ton of municipal green waste (MGW) in Lima Peru under 4 different scenarios: 1) Final disposal in authorized landfill, 2) Final disposal in informal landfill, 3) composting and 4) biochar production using a low-cost, low tech Kon-Tiki reactor. Results The results demonstrate the very clear potential for climate change mitigation from biochar production using low tech and therefore accessible technology in a typical developing world context. The carbon footprint of producing biochar was lower than for composting and biochar and compost both had carbon footprints significantly lower than landfilling. Conclusion We argue that the standards used by nascent platforms for trading carbon removal credits generated by biochar should relax the technology requirement to favor engagement and participation of small-scale market participants in low-income countries. Waste management in the developing world presents significant challenges but often starts from a very low base which means there is large potential for reducing emissions, as well as for sequestering carbon.