In Defense of 2.0°C: The Value of Aspirational Environmental Goals

Aspirational goals, such as the Paris Agreement’s goals of avoiding a global temperature increase of 1.5°C or 2.0°C, can be found throughout environmental law. Such goals, though sometimes unrealistic, perform important functions. They may serve as asymptotic directives that guide implementing entities; yardsticks to measure and evaluate progress; expressions of social values; and expanders of policy space. As asymptotic directives, aspirational goals may push actors to achieve more than they otherwise might accomplish. Incorporated into treaties or statutes, they can serve as guideposts for implementing concrete substantive and procedural requirements. With the passage of time, aspirational goals function as yardsticks for measuring progress and identifying needed adjustments and course corrections. Aspirational goals also express messages about society’s priorities while seeking to shape its values. While aspirational standards can deflect alternative approaches, weaken support for policy objectives, or mislead the public, they ultimately can expand the range of possible outcomes and motivate actions that achieve significant progress towards lofty aspirations.