Countries’ ability under the Paris Agreement to limit warming to 2˚C, if not to 1.5˚C, has been in question since the adoption of the treaty in 2015. This has prompted calls for countries to increase the ambition of the mitigation pledges in their Nationally Determined Contributions (NDCs) to close the ambition gap between countries’ NDCs and global temperature goals. In addition to the ambition gap, there is an implementation gap as countries’ current national policies fall short of the mitigation pledges outlined in their NDCs (Lee et al. 2023).
Hence, to reach the temperature goals of the Paris Agreement, countries must formulate increasingly ambitious international pledges and vertically harmonize their national policies with these pledges. Yet, harmonization is a complex task that involves reconciling the interests of a multitude of diverse actors across different levels and sectors. As such, many countries exhibit different levels of political commitment to mitigate climate change in their NDCs and national policies (e.g., Baker 2023; Ingold and Pflieger 2016; Peterson 2021).
Against this backdrop, this research project addressed the following questions:
(i) To what degree do countries formulate NDCs that are sufficiently ambitious so as to be aligned with their fair share of the global temperature goals, i.e., to close the ambition gap?
(ii) To what degree do countries translate their NDCs into their national policies (policy objectives and instruments), i.e., to close the implementation gap?
(iii) What drives countries to under- or outperform regarding both the ambition and implementation (i.e., harmonization) gaps?
This project builds upon precedent work in international relations, comparative politics, political economy, and policy sciences that evaluates countries’ climate (policy) performance and explain the gap between countries’ international commitments and (sub-)national policies. We complement previous endeavors (e.g., Climate Action Tracker, Climate Change Performance Index) assessing the fairness or compatibility of countries’ climate policies with pathways towards the global temperature goals by developing the Vertical Policy Harmonization (VPH) Indices (Baker 2023; Baker et al. under review) that quantify the gap between countries’ NDCs and national mitigation policies along three key dimensions of mitigation policymaking. The Target Index compares the level and scope of the greenhouse gas (GHG) reduction targets of 105 countries’ NDCs and national policies. The Policy Effort Index incorporates countries’ climate policy mix to assess the credibility of 36 countries’ targets. The VPH Indices show that despite approximately a quarter of countries having national targets that are either in line with or more ambitious than their NDC target, most countries, accounting for 40% of global GHG emissions, fall short of their targets given countries’ relatively insufficient policy mixes.
We draw on these indices and address our research questions from three perspectives. In the first perspective, we focus on the international level and present a typology that incorporates both the ambition and harmonization of countries’ NDCs and national policies (Castro and Kammerer working paper). Under this typology, countries are categorized as leaders (when national policies outperform ambitious NDCs), performative (when national policies fall short of ambitious NDCs), laggards (when national policies and NDCs are unambitious), or cautious (when national policies overperform unambitious NDCs). We find that most countries are characterized as laggards or cautious, while only a handful are categorized as performative, and even fewer as leaders. Moreover, we formulate a set of hypotheses relating to countries’ connectedness to the international negotiations (e.g., level of active participation) and negotiation delegations (e.g., size, resources). Our analyses suggest that developing countries with stronger engagement in UN climate negotiations and the broader ecosystems of international climate policy processes tend to have more ambitious NDCs and stronger national policies (Castro et al. working paper).
The second perspective focuses on the effect of macro-level factors, such as countries’ institutional setting (e.g., degree of democracy) and interests (e.g., vulnerability, fossil fuel dependency), on shaping vertical (dis)harmony. We find that fossil fuel dependency in democracies constrains the harmonization of NDC and national-level targets, even in the face of high vulnerability and low abatement costs (Baker 2023). Moreover, our results suggest that countries with decentralized political systems tend to be harmonized or have overperforming national policies, while countries with carbon intensive economies and few political constraints are associated with disharmony stemming from underperforming national policies (Blindenbacher et al working paper; Kammerer working paper).
In the third perspective we aim to explain the extent to which countries’ NDCs and national policies are harmonized by the way of the domestic policy process. We are specifically interested in how key aspects of countries’ climate policy subsystem (e.g., the level of actor involvement, belief conflict, the presence of actors who are involved in both the foreign and domestic climate policy processes) determine the adoption of national climate policies, which in turn drives harmonization. So far, we have run eight policy elite surveys to collect data on the relevant factors of a policy subsystem and the preliminary results indicate that the presence of “two-level connectors” (i.e., policy actors who are involved in both NDC development and national climate policymaking processes) is relevant in explaining the gap between countries’ NDCs and national mitigation policies.
This project demonstrates countries’ varying ability in harmonizing their NDCs and national climate policies and uncovers the multitude of factors that drive countries’ vertical (dis)harmony. The expansion of the VPH Indices will increase the robustness of our present findings and will enable us to discern whether vertical disharmony is a bug or feature of the global climate change regime. In a normative context, it is up for debate as to whether harmonization should be encouraged or if disharmony should be tolerated as a norm of harmonization may result in both (non-)consequential benefits and disadvantages (Baker and Roser working paper). Increasing the temporal coverage of the VPH Indices will not only inform this normative discussion, but also further theory-building on the interplay between ambition and harmonization and more immediately demonstrate the effectiveness of the incremental ambition-raising framework that is a cornerstone of the Paris Agreement’s approach to achieving its long-term ambition.
We draw on these indices and existing measures of ambition to present a typology that incorporates both the ambition and harmonization of countries’ NDCs and national policies (Castro and Kammerer working paper). Under this typology, we categorize two countries (i.e., Nigeria, Comoros) as leaders given their national policies outperform their ambitious NDCs and a handful of countries (i.e., Colombia, Cyprus, Democratic Republic of Congo, Senegal and Uganda) as performative as their national policies fall short of their ambitious NDCs. Most countries, however, are characterized as laggards (e.g., several EU member states, India, Saudi Arabia, United Kingdom, the United States) with unambitious NDCs and national policies or cautious (e.g., Australia, Brazil, China, Denmark, Germany, Japan, Vietnam) as they have national policies that overperform their unambitious NDCs.
We use the VPH Indices and formulate three sets of hypotheses to address our research questions. The first set focuses on macro-level factors, such as countries’ institutional setting (e.g., degree of democracy) and interests (e.g., vulnerability, fossil fuel dependency). We find that fossil fuel dependency in democracies constrains the harmonization of NDC and national-level targets, even in the face of high vulnerability and low abatement costs (Baker 2023). Moreover, our results suggest that countries with decentralized political systems tend to be harmonized or have overperforming national policies, while countries with carbon intensive economies and few political constraints are associated with disharmony stemming from underperforming national policies (Blindenbacher et al working paper; Kammerer working paper).
The second set of hypotheses includes international factors with a focus on the countries’ connectedness to the international negotiations (e.g., level of active participation) and negotiation delegations (e.g., size, resources). Our analyses suggest that developing countries with stronger engagement in UN climate negotiations and the broader ecosystems of international climate governance processes tend to have more ambitious NDCs and stronger national policies (Castro et al. working paper).
The third set addresses the research questions by the way of the domestic policy process. We are specifically interested in how key aspects of countries’ climate policy subsystem (e.g., the level of actor involvement, belief conflict, the presence of actors who are involved in both the foreign and domestic climate policy processes) determine the adoption of national climate policies, in turn driving harmonization. So far, we have run eight policy elite surveys to collect data on the relevant factors of a policy subsystem and the preliminary results indicate that the presence of “two-level connectors” (i.e., policy actors who are involved in both NDC development and national climate policymaking processes) is relevant in explaining the gap between countries’ NDCs and national mitigation policies.
