The Drivers and Barriers of Enhanced Climate Pledges: A Mixed-Method Study

The 2015 Paris Agreement requires its parties to submit five-yearly climate pledges in the form of Nationally Determined Contributions (NDCs) to indicate their sustained commitment to tackling anthropogenic climate change. These pledges constitute an important aspect of the Paris Agreement’s ambition mechanism that seeks to strengthen climate change mitigation over time. After the initial round of NDCs, most parties – including the world’s major emitters – have now submitted an updated or revised NDC as part of the second round of pledges. To assess whether the Paris Agreement’s ambition mechanism is functioning as intended, it is important to understand whether the second round of NDCs represent an increase in ambition and, if so, to what extent ambitions have increased. Moreover, there is a significant gap in the literature regarding the determinants of NDC development. In other words, what drives or hinders increased NDC ambition? Addressing these questions, this paper aims to provide one of the first systematic and generalisable analyses of the role of key drivers of and barriers to enhanced NDCs. Our study implements a mixed-method design, employing both quantitative and qualitative methods. The study is structured in three inter-connected parts. First, the paper follows an innovative multi-dimensional decision-tree questionnaire to evaluate the change in ambition from the first NDC to the updated or revised NDC. Hence, we generate data regarding change in the mitigation ambition of countries’ NDCs based on a number of diverse dimensions of ambition, including changes in targets. Second, the paper identifies several potential drivers and and barriers of national climate ambition, focused on politics (e.g. elections), structural context (e.g. natural resource dependency and climate hazards) and the economy (e.g. economic growth). Third, the paper qualitatively investigates the factors that support and dissuade the development of enhanced NDCs for key countries. We identify five critical cases based on the quantitative study, namely Australia, Brazil, Morocco, South Africa and the US. We offer two key contributions to the literature on (comparative) climate politics. First, we evaluate both overall and multi-dimensional ambition change based on updated or revised NDCs, which show whether and to what extent countries enhanced their pledges. These results improve our knowledge of the likelihood of the world achieving the Paris Agreement goals. Second, on the basis of the mixed-method analysis, our study presents a generalisable analysis of the significant drivers and barriers of enhanced NDCs, with examples from key countries.