Optimal allocation of nature-based solutions to achieve climate mitigation and adaptation goals

1. Nature -based solutions (NbS) can prevent further climate change and increase local communities' capacity to adapt to the current impacts of climate change. However, the benefits obtained from implementing NbS are not distributed equally across people. Thus, it is key to further understand how people are im- pacted when implementing NbS.2. We developed a multi-objective prioritization approach to identify changes in (i) the biophysical provision of ecosystem services, (ii) optimal allocation of NbS and (iii) monetary benefits when targeting climate mitigation versus climate adapta- tion goals. We used the increase in metric tons of carbon storage as representa- tive of climate mitigation and the decrease in on -site and downstream tons of sediment per year as representative of climate adaptation.3. Planning strategies that target climate mitigation or climate adaptation goals sep- arately represent a loss of between 30% and 60% of the maximum possible car- bon sequestration or sediment retention benefits. Conversely, targeting climate mitigation and climate adaptation goals at the same time captured more than 90% of the maximum possible benefits for all objectives.4. Priority NbS in the mitigation planning strategy included soil and water conserva- tion and forest rehabilitation, while priority NbS in the adaptation planning strat- egy included grassland rehabilitation and hill terrace improvement.5. Targeting mitigation and adaptation goals at the same time captures 35M USD (89% of the maximum attainable) in value of carbon restored and retained, and 2M USD (100% of the maximum attainable) of avoided maintenance costs to the KGA hydropower plant. Conversely, failing to incorporate adaptation goals when developing climate plans only captures 1M of avoided maintenance costs to the KGA hydropower plant.6. Our approach can be replicated in other locations to promote cost-effective in- vestments in NbS able to secure both global and local benefits to people. This can improve the outcomes of international climate change financial schemes like the Green Climate Fund and the UN- REDD+ program.