Can climate rankings tell us which country is a good performer?

• Environmental indices appear objective, but they are shaped by subjective design choices and underlying worldviews.
• No single environmental index can accurately judge climate performance; developers must transparently state their design assumptions.
• Policymakers and the media should consult a range of indices rather than relying on one, as rankings reflect specific value judgments.

Conflicting Assessments

• The 2026 Environmental Performance Index (EPI) and the 2026 Climate Change Performance Index (CCPI) provide widely divergent rankings for the same countries.
  • EPI-2026 ranks the U.S. 43rd out of 177 countries, a relatively high score.
  • CCPI-2026 places the U.S. among the three worst performers, alongside Saudi Arabia and Iran.

The Role of Methodology

• Divergence is traced to fundamental design choices regarding fairness and measurement:
  • EPI focuses on total greenhouse gas emissions, reflecting atmospheric physics where only absolute accumulation matters.
  • CCPI focuses on per-person emissions, based on the ethical premise that every person has an equal right to atmospheric resources.
• Modifying the EPI to favor fairness-based indicators instead of total-emission indicators causes European nations, which rank highly on the original, to drop to the bottom half.

Implications for Governance

• Claiming an index is a "neutral, scientific verdict" is a fallacy; indices are inherently value-laden.
• Past rejections of indices (e.g., India rejecting EPI in 2022, Australia dismissing CCPI in 2019) were disputes over normative framing, not data errors.
• Like the Mercator map projection, which distorted geographic perception by prioritizing navigation for ships, climate rankings can unintentionally encode worldviews that distort political and social perspectives on environmental responsibility.