Green nudges are used to promote conservation and pro-environmental behavior. This study examines the lasting effectiveness of a green default nudge in paper conservation, where price incentives are absent. At a private college in New York City, the default print setting was changed from single-sided to double-sided in Spring 2019, accompanied by a salient pop-up window that asked students to print double-sided. Analyzing student-level data over four semesters (Spring 2018 and Fall 2018 as control, Spring 2019 and Fall 2019 as treatment), this research contributes to the literature as it studies the effect of the nudge in the absence of pecuniary incentives. The findings support the hypothesis that this green default nudge was effective in promoting paper conservation and increasing resource efficiency. Results show that double-sided printing increased while single-sided printing decreased, leading to an overall reduction in paper usage. Employing a panel regression model with student fixed effects, this study finds that the nudge had a statistically significant effect in reducing the sheets per page ratio, and it improved the efficient use of paper by 19 percent. This inexpensive behavioral intervention proves successful in promoting environmental behavior and reducing paper consumption, which reduces greenhouse gas emissions.