<p>Negative emission technologies and practices (NETs) are crucial for climate change mitigation but raise technical, ecological, and social challenges. We surveyed 5,310 European citizens across six countries to examine how the national responsibility for causing climate change and capacity to implement NETs are related to how fair people think it is for a country to implement NETs. Following an experimental design, participants evaluated how fair it is to implement NETs in a country with either high or low CO₂ emissions (reflecting a country’s responsibility) and sufficient or insufficient resources (reflecting a country’s capacity). Next, they evaluated their own country’s responsibility and capacity, and fairness of implementing NETs in their country. Results show that people view implementing NETs as fairer in countries with high CO₂ emissions and sufficient resources, with responsibility to be the strongest predictor of perceived fairness. Furthermore, people perceive NETs implementation fairer in their country when they perceive it as a larger historical and current emitter, with more available land and income. It is critical that public perceptions of fairness inform policymaking to ensure socially responsible governance and the legitimacy of NETs implementation.</p>