About the EPI

The 2020 Environmental Performance Index (EPI) provides a data-driven summary of the state of sustainability around the world. Using 32 performance indicators across 11 issue categories, the EPI ranks 180 countries on environmental health and ecosystem vitality. These indicators provide a gauge at a national scale of how close countries are to established environmental policy targets. The EPI offers a scorecard that highlights leaders and laggards in environmental performance and provides practical guidance for countries that aspire to move toward a sustainable future.

EPI indicators provide a way to spot problems, set targets, track trends, understand outcomes, and identify best policy practices. Good data and fact-based analysis can also help government officials refine their policy agendas, facilitate communications with key stakeholders, and maximize the return on environmental investments. The EPI offers a powerful policy tool in support of efforts to meet the targets of the UN Sustainable Development Goals and to move society toward a sustainable future.

Overall EPI rankings indicate which countries are best addressing the environmental challenges that every nation faces. Going beyond the aggregate scores and drilling down into the data to analyze performance by issue category, policy objective, peer group, and country offers even greater value for policymakers. This granular view and comparative perspective can assist in understanding the determinants of environmental progress and in refining policy choices.

Funding from the The McCall MacBain Foundation of Canada supports the EPI work at both Yale and Columbia. The EPI research team is deeply grateful for this generous support.

Suggested Citation:
Wendling, Z. A., Emerson, J. W., de Sherbinin, A., Esty, D. C., et al. (2020). 2020 Environmental Performance Index. New Haven, CT: Yale Center for Environmental Law & Policy. epi.yale.edu


Explaining performance

A number of striking conclusions emerge from the 2020 EPI rankings and indicators. First, good policy results are associated with wealth (GDP per capita), meaning that economic prosperity makes it possible for nations to invest in policies and programs that lead to desirable outcomes. This trend is especially true for issue categories under the umbrella of environmental health, as building the necessary infrastructure to provide clean drinking water and sanitation, reduce ambient air pollution, control hazardous waste, and respond to public health crises yields large returns for human well-being.

Second, the pursuit of economic prosperity – manifested in industrialization and urbanization – often means more pollution and other strains on ecosystem vitality, especially in the developing world, where air and water emissions remain significant. But at the same time, the data suggest countries need not sacrifice sustainability for economic security or vice versa. In every issue category, we find countries that rise above their economic peers. Policymakers and other stakeholders in these leading countries demonstrate that focused attention can mobilize communities to protect natural resources and human well-being despite the strains associated with economic growth. In this regard, indicators of good governance – including commitment to the rule of law, a vibrant press, and even-handed enforcement of regulations – have strong relationships with top-tier EPI scores.

Third, while top EPI performers pay attention to all areas of sustainability, their lagging peers tend to have uneven performance. Denmark, which ranks #1, has strong results across most issues and with leading-edge commitments and outcomes with regard to climate change mitigation. In general, high scorers exhibit long-standing policies and programs to protect public health, preserve natural resources, and decrease greenhouse gas emissions. The data further suggest that countries making concerted efforts to decarbonize their electricity sectors have made the greatest gains in combating climate change, with associated benefits for ecosystems and human health. We note, however, that every country – including those at the top of the EPI rankings – still has issues to improve upon. No country can claim to be on a fully sustainable trajectory.

Fourth, laggards must redouble national sustainability efforts along all fronts. A number of important countries in the Global South, including India and Nigeria, come out near the bottom of the rankings. Their low EPI scores indicate the need for greater attention to the spectrum of sustainability requirements, with a high-priority focus on critical issues such as air and water quality, biodiversity, and climate change. Some of the other laggards, including Nepal and Afghanistan, face broader challenges such as civil unrest, and their low scores can almost all be attributed to weak governance.

Refining metrics

Innovations in the 2020 EPI data and methodology reflect the latest advances in environmental science and indicator analysis. Notably, the 2020 rankings include for the first time a waste management metric and a pilot indicator on CO2 emissions from land cover change. Other new indicators deepen the analysis of air quality, biodiversity & habitat, fisheries, ecosystem services, and climate change. Full documentation of the methodology is available on this website, and the EPI team invites feedback and suggestions for strengthening future versions of the Index.

While the EPI provides a framework for greater analytic rigor in policymaking, it also reveals a number of severe data gaps that limit the analytic scope of the rankings. As the EPI project has highlighted for two decades, better data collection, reporting, and verification across a range of environmental issues are urgently needed. The existing gaps are especially pronounced in the areas of agriculture, water resources, and threats to biodiversity. New investments in stronger global data systems are essential to better manage sustainability challenges and to ensure that the global community does not breach fundamental planetary boundaries.

The inability to capture transboundary environmental impacts persists as a limitation of the current EPI framework. While the current methodology reveals important insights into how countries perform within their own borders, it does not account for “exported” impacts associated with imported products. With groundbreaking models and new datasets emerging, the EPI team has been working to produce new metrics that account for the spillovers of harm associated with traded goods in an interconnected world.

Global pandemic

The 2020 EPI emerges in the midst of the COVID-19 crisis that has challenged public health systems and disrupted economic activity across the world. The global pandemic has made clear the profound interdependence of all nations and the importance of investing in resilience. Unintended consequences of the economic shutdown in many nations include a sharp drop in pollution levels and the return of wildlife. The EPI team hopes that this unexpected glimpse of what a sustainable planet might look like from an ecological perspective – albeit at a terrible price in terms of public health and economic damage – will inspire the policy transformation required for a sustainable future that is both economically vigorous and environmentally sound.


Policy Objectives in the 2020 EPI

The relationship between 2020 EPI Score and GDP per capita shows a strong positive correlation, although many countries out- or underperform their economic peers.

Scatter Chart

2020 EPI Framework

The framework organizes 32 indicators into 11 issue categories and two policy objectives, with weights shown at each level as a percentage of the total score.
2020 EPI Framework