Harnessing carbon payments to protect biodiversity.

Initiatives to reduce carbon emissions from deforestation and degradation (REDD) are providing increasing incentives for forest protection. The collateral benefits for biodiversity depend on the extent to which emissions reductions and biodiversity conservation can be achieved in the same places. Globally, we demonstrate spatial trade-offs in allocating funds to protect forests for carbon and biodiversity and show that cost-effective spending for REDD would protect relatively few species of forest vertebrates. Because trade-offs are nonlinear, we discover that minor adjustments to the allocation of funds could double the biodiversity protected by REDD, while reducing carbon outcomes by only 4 to 8%.