<p><strong>Behaviour change is a crucial tool for mitigating climate change, but it should be applied ethically and equitably. Nudge interventions and liberal paternalism have become increasingly popular, but are also subject to various ethical criticisms and challenges. To explore some of these criticisms, this study investigates how pro-environmental nudges, which subtly influence people’s choices without restricting their options, affect decision-making consciousness and climate justice outcomes.</strong></p><p>The study draws on dual process theory, which distinguishes between conscious (System 2) and non-conscious (System 1) decision-making, and values theory, which suggests that value-action alignment is associated with conscious choices. Climate justice and equity elements were also included, via individuals’ carbon footprint measurements. Data was collected via an online survey, which included a charity selection question as a proxy measure for pro-environmental behaviour choice. Half of the participants received a neutral charity question, and the other half received a default-framing nudge with the pro-environmental charity presented as the default. The control group showed signs of System 2 decision-making, and biospheric values and carbon footprints correlated with the pro-environmental charity choice. The default-framing nudge was effective at non-consciously encouraging participants to make the pro-environmental choice (95% versus 58% in the control). The treatment group showed signs of System 1 decision-making, and only, carbon footprints correlated with the pro-environmental charity choice. Unlike biospheric values, carbon footprints moderate the effectiveness of a nudge. The nudge was less effective for participants with higher carbon footprints.</p><p>The study confirmed that nudges can promote pro-environmental behaviour. However, it highlighted key ethical risks including inequitable results and reduced decision-making consciousness. Future research can benefit from these findings, by acknowledging these risks, and including elements such as carbon footprints to build more holistic, equitable, measures of success.</p>