Green nudge
A choice-architecture change designed to encourage environmentally friendly behavior without mandates.
What it means
Green nudges apply behavioral design to pro-environmental ends — setting eco-friendly options as defaults (renewable energy tariffs, double-sided printing), making consumption salient through feedback (energy-use reports comparing you to neighbors), invoking social norms, and reducing friction for sustainable choices. They are popular because they are cheap, politically palatable, and preserve freedom of choice. The central debate is whether they are commensurate with the scale of environmental problems: critics in the i-frame versus s-frame argument warn that focusing on green nudges can crowd out, or even be used to delay, structural measures like carbon pricing that have far larger effects. Evidence shows some green nudges (especially green defaults) are highly effective, while others produce small or short-lived change, and rebound effects can erode gains. It matters as a test case for how much individual-level behavioral policy can contribute to collective, systemic challenges.
Examples
Switching a utility's default to a green energy plan, with customers free to opt out, can move the large majority onto renewables — a far bigger shift than asking them to opt in.
Making the vegetarian dish the default at a conference lunch, with meat freely available on request, shifts most plates without banning anything or lecturing anyone about their diet.
Households fitted with efficient LED bulbs leave the lights on longer, because light now feels cheap. The rebound eats part of the saving the nudge was installed to deliver.
First described in Behavioral environmental policy (2010s).