Willing to act, failing to impact : psychological and social drivers of voluntary climate action

Despite widespread concern about climate change, voluntary mitigation efforts often fail to maximize impact. In two online experiments (n = 1, 500), we elicit willingness to mitigate (WTM) by allowing subjects to delete actual CO2 allowances and examine how they allocate the WTM between their own and another's footprint. While 75% contribute a nonzero WTM, allocations are often inefficient, and many avoid freely available footprint information, suggesting limited efficiency concerns. Self-reported motives show that only half prioritize impact, while others cite fairness, personal responsibility, or intuition. Moreover, both WTM and efficiency are malleable by impact-unrelated nudges: a video emphasizing personal responsibility increases both, whereas social image based on the own footprint raises WTM but reduces efficiency. Our results suggest that voluntary climate action is shaped as much by psychological and social factors as by concern for impact.