IPBES ≠ IPCC

•IPCC has one function: undertaking assessments.•IPBES has four: it also supports knowledge generation, capacity building, and policy.•This difference is appropriate, but not reflected in IPBES’ current budget allocation.•IPCC WG II (climate change adaptation) might also consider strengthening such functions. The characteristics of the physical science basis and mitigation of climate change lend themselves well to a science–policy interface focused on global assessment—the function of the Intergovernmental Panel on Climate Change (IPCC). By contrast, the Intergovernmental Science–Policy Platform on Biodiversity and Ecosystem Services (IPBES) needs three additional functions of knowledge generation, capacity-building, and policy support, in addition to traditional assessment, and the same is true for climate change adaptation. These functions are included in the work program for IPBES, but their total share of the budget, currently less than a third, is inadequate. For climate change adaptation they are delivered by mechanisms like the Nairobi Work Programme and the Adaptation Committee, which should similarly receive greater attention.