As pressure mounts on countries to reduce carbon emissions, there is increasing interest in understanding what drives "carbon behaviours", in order to inform behavioural change policies. This study examined the impact of psychological and demographic variables, on "carbon behaviours". Secondary data analysis was carried out to investigate the antecedents of residential energy use reduction behaviours and choice of transportation mode for commuting and grocery shopping. Models explained 18.2% and 25.2% of variance in energy use and transport behaviours respectively. Being concerned about climate change and having an environmental identity increased household energy reduction behaviour but did not significantly affect travel mode choices. The antecedents of travel mode decisions were attitudes towards the travel mode itself, and demographic and structural variables such as income and distance travelled. Findings suggest that using "green" messaging will help encourage behavioural change in energy use, but contribute little to encouraging change in travel mode decisions.