The comfortable perception that global environmental challenges can be met through marginal lifestyle changes does not bear scrutiny. We live at a time when we need urgent and ambitious changes, yet the cumulative impact of large numbers of people making marginal improvements in their environmental impact will be a marginal collective improvement in environmental impact. Despite this arithmetical truism, many environmental organisations and governments continue to insist that progress will only be achieved by encouraging simple and painless pro-environmental lifestyle changes. They make this insistence while blithely relying on “spillover” to extend these environmentally insignificant changes to more ambitious and environmentally relevant changes. Yet the evidence for pro-environmental spillover is at best ropey.
Environmental campaigners should be clear with themselves about whether a campaign is aimed at delivering a specific behavioural change (the actual focus of the campaign – e.g. reduced carrier bag use) or whether it is aimed at helping to elicit a wider set of behavioural changes (through positive spillover effects). This discipline would oblige campaigners to be clear about two things: first, the inadequacy of responses to environmental problems that rely upon widespread adoption of marginal reductions in individual carbon footprint; and second, the challenges facing them if they are to use such campaigns as vehicles for promoting more ambitious changes.