People’s perception of their own efficacy is a critical precursor for adaptive behavioural responses to the threat posed by climate change. The present study investigated whether components of climate efficacy could be enhanced by short video messages. An online study (N = 161) compared groups of participants who received messages focusing on individual or collective behaviour. Relative to a control group, these groups showed increased levels of response efficacy but not self-efficacy. However, this did not translate to increased climate commitment; (...) mediation analysis suggested that the video messages, while increasing efficacy, may also have had a counterproductive effect on behavioural intentions, possibly by reducing the perceived urgency of action. This finding reinforces the challenge faced by climate communicators seeking to craft a message that boosts efficacy and simultaneously motivates adaptive responses to the climate crisis. (shrink)