A Yale professor debuted the 2018 Environmental Performance Index at the World Economic Forum this January in Davos, Switzerland.

A biennial report released by Yale and Columbia, the Environmental Performance Index details the environmental performance of countries across 10 key environmental areas. Daniel Esty, professor of environmental law and policy at the Yale Law School and School of Forestry & Environmental Studies, presented the report at this year’s World Economic Forum. Later, Esty and University President Peter Salovey discussed the Environmental Performance Index in a Facebook Live event.

“It’s really important to acknowledge where countries are performing well, but if a country’s being held back by something, that’s also a relevant conversation, as it helps us focus where our priorities should be,” said Zach Wendling, principal investigator on the Environmental Performance Index team and a postdoctoral researcher at the forestry school. “The United States is not doing very well with their climate emissions, and we want to know why the U.S. is lagging behind the other industrialized countries.”

Countries in the Environmental Performance Index are ranked on their overall standing as well as their performance in key areas, ranging from their air quality to their protection of forests. Nations like first-ranking Switzerland have sustained strong economic performance while simultaneously limiting pollution and damage to natural resources, Esty said. On the flip side, nations such as India, ranked 177 out of 180, have struggled to balance these two policy goals.

The United States ranked 27th in the Environmental Performance Index, placing it behind most other industrialized nations. While the country ranked highly on some markers, including air quality and sanitation, it performed poorly on others, such as deforestation and greenhouse gas emissions.

Every year, Salovey hosts a reception for Yale alumni and affiliates at the World Economic Forum, where he highlights Yale work, Wendling said. The Environmental Performance Index was one of the three projects showcased this year, and members of the Environmental Performance Index team, including Esty and Wendling, attended the conference to present their work. At the reception, the professors spoke with conference attendees from all over the world, many of whom had specific questions about where on the index their countries ranked and why.

Conversation on the 2018 report has been dominated by the topic of air pollution, with the authors going as far as to declare it the leading environmental threat to public health. This concern is especially acute in Asian countries, where air pollution in several major cities has reached disastrous levels.

The report has received significant media attention in India, said Alex de Sherbinin, co-author of the report, because of the nation’s weak standing on the index. India has recently experienced a marked increase in air pollution and emissions, which were large contributing factors to its low rank.

“For years, government policy has been dictated by ‘Let’s get the GDP higher’ and ‘Let’s increase economic growth,’” said Alex de Sherbinin, who works at an environmental data analysis center at Columbia. “Governments need some way to identify the importance of different environmental issues and target the ones they’re doing the worst on. So that’s what the Environmental Performance Index does.”

In the past, the team has communicated with a number of national governments about their placements in the rankings, de Sherbinin said. The team uses consistent data sources rather than nations’ self-reported figures, he added. And sometimes, governments lodge complaints about the data selection and metrics employed in the index.

Often, de Sherbinin continued, a country’s low ranking can draw national attention and publicity to an important environmental issue. Years ago, South Korea received a low rank in the report, due in part to high levels of air pollution. The disappointing score triggered a “national soul-searching campaign” that led to many important policy changes, he said.

Every two years, the team changes the report’s metrics to better capture country performance, Wendling said. For example, the team focused on many different greenhouse gases in the 2018 report, whereas the 2016 report studied only carbon dioxide.

Many of the changes to the metrics in the report stem from advancements in science and data, Wendling continued. But there is still room for improvement in global metrics, he added, saying that the team struggled to find accurate global data on certain topics, such as water quality and sustainable agriculture.

The report was sponsored in part by the McCall MacBain Foundation, which values the report’s ability to get countries to “sit up and listen,” said John McCall MacBain, who established the foundation. Countries that lag behind in the rankings can turn to those that have been more successful to see how they implement their policies, he added.

“Most of the top countries on the list are members of the European Union,” MacBain said. “So Europe must be doing something right.”

According to the Intergovernmental Panel on Climate Change, industrial activity in the past 150 years has raised atmospheric carbon dioxide levels from 280 parts per million to over 400 parts per million.

Maya Chandra | maya.chandra@yale.edu