Specialist commissions could be established if the post-2020 regime assumes scientific or policy study roles. The science-policy interface is well-developed under the ozone regime. Regular scientific assessments guide policy-makers: the Scientific Assessment Panel (SAP), the Environmental Effects Assessment Panel (EEAP), and the Technology and Economic Assessment Panel (TEAP) each prepare, about every 3-4 years, major assessment reports that update the state of understanding in their purviews.