资源环境科技发展态势分析平台

Background. The contribution of information and communication technologies (ICTs) to a low carbon economy is unclear. Previous reviews emphasise the need to assess the specific factors that determine the environmental impacts of ICTs, but none of them link those factors to the magnitude of the impacts on energy consumption and carbon emissions. Our study aims to fill this evidence gap. Methods/Design. We restrict our analysis to a single application domain, namely e-materialisation, defined as the partial or complete substitution of material products with electronic equivalents. We conduct the first systematic literature review of the direct and higher order impacts of the digitalisation of goods on energy consumption.

Results/Synthesis. We identify 31 relevant studies that we sort into five categories, namely: 'e-publications' (e-books, e-magazines and e-journals); 'e-news'; 'e-business'; 'e-music'; and 'e-videos and games'. All but one of the 31 studies use life-cycle analysis and employ a range of product-system configurations, functional units, system boundaries and allocation rules. Confining attention to direct and substitution effects, the studies suggest potential energy savings from e-publications, e-news and e-music, and less potential from e-business and e-videos/games. However, different assumptions for key variables (such as the lifetime and energy efficiency of user devices, the extent to which personal transport is displaced and the number of users of material and digital products) lead to very different estimates-including many where lifecycle energy consumption increases. Most of the studies assume that digital goods substitute for material goods and all of them neglect rebound effects-which suggests that they overestimate energy savings.

Discussion. Given the diversity and context-specificity of the available evidence, the optimistic assumptions that are frequently used (e.g. perfect substitution) and the neglect of rebound effects, we cannot conclude that e-materialisation has delivered significant energy savings to date or is likely to do so in the future.