In the year 2020, countries’ plans for emissions reductions in the form of Nationally Determined Contributions (NDCs) shall be renewed and/or updated. There is an urgent need for increased ambition, as illustrated in the IPCC Special Report on 1.5°C, which states that current NDCs are not consistent with a pathway to 1.5°C and would instead lead to warming of 3.5°C. This means that Parties to the Paris Agreement need to go beyond current commitments by 2030. One way to raise ambition is to involve, include and work together with sub-national levels of government, i.e. Collaborative Climate Action (CCA).

While the estimated contributions of local governments and other non-state actors to addressing climate change differ, some estimates put the global potential for urban greenhouse gas emissions reductions to be around 3 gigatonnes CO2-equivalents annually until 2030. This amounts to about one quarter of the gap between the commitments in the current NDCs of national governments and the target of keeping global warming below 2°C.

More than one-third of the identified mitigation potential in cities depends on collaborative climate action among national, regional and local governments, including building codes, decentralized renewables and mass transit infrastructure. This means national governments need to plan for and enable local climate action.