**Abstract: **Accurate models of pro-environmental behavior can support environmental sustainability. Previous studies identifying the psychological predictors of pro-environmental behavior rarely accounted for environmental impact. We studied the greenhouse gas emissions of clothing purchasing across four countries and found that psychological factors like attitudes and personal norms strongly predicted a common self-reported behavior scale of clothing purchasing, but only weakly predicted clothing-related greenhouse gas emissions. This result challenges widespread inferences using pro-environmental behavior scales and suggests that psychological factors may be a poor predictor of clothing-related environmental impact.