This will involve assessing climate risks and opportunities within national government processes, at sectoral and project levels, and in both urban and rural contexts. The uncertainty surrounding climate impacts means that flexibility is important. Participation of all major emission sources, sectors and countries would reduce the costs of mitigation and help to address potential leakage and competitiveness concerns. This Outlook models a 450 ppm Core scenario which suggests that achieving the 2 °C goal would require establishing clear carbon prices that are increased over time.