Beyond ambition: increasing the transparency, coherence and implementability of Nationally Determined Contributions

With almost every country submitting their intended Nationally Determined Contribution (NDC) before or shortly after the 2015 Paris Climate Conference, these climate action plans were key to the landmark adoption of the Paris Agreement, and will be central to its implementation (Pauw et al., 2018). Research quickly identified the ‘headline numbers’ of NDCs: full implementation would reduce mean global warming by 2100 from approximately 3.6°C to 2.7°C above pre-industrial levels (Höhne et al., 2016; Rogelj et al., 2016). Research also showed that if ambition is not increased before 2030, global mean temperature increase can no longer be limited to 1.5°C above pre-industrial levels (UNEP, 2018). The conclusions of the IPCC Special Report Global Warming of 1.5°C (IPCC, 2018) underscore the urgency of greater ambition. But ambition alone is not enough: to be able to realize their ambitions, countries also need to enhance the effectiveness of the plans and policies underpinning their NDCs. This requires improvements to the transparency, coherence and implementability of NDCs. Almost all countries have now ratified the Paris Agreement, and many are in the process of updating their NDCs. It is crucial for the success of the Paris Agreement that the updated NDCs build on and learn from the first round of NDCs. This special issue Making Climate Action More Effective: Lessons Learned from the First Nationally Determined Contributions provides insights, and aims to stimulate debate, on how to strengthen NDC effectiveness. The eight papers in the special issue cover mitigation, adaptation and means of implementation, and discuss key elements of the Paris Agreement and broader climate policy, including the Enhanced Transparency Framework and the Paris Committee on Capacity Building, as well as considerations of equity and development