A systematic review of the evidence on decoupling of GDP, resource use and GHG emissions, part II: synthesizing the insights

Strategies toward ambitious climate targets usually rely on the concept of ‘decoupling’; that is, theyaim at promoting economic growth while reducing the use of natural resources and GHGemissions. GDP growth coinciding with absolute reductions in emissions or resource use isdenoted as ‘absolute decoupling’, as opposed to ‘relative decoupling’, where resource use oremissions increase less so than does GDP. Based on the bibliometric mapping in part I(Wiedenhoferet al,2020Environ. Res. Lett.15063002), we synthesize the evidence emerging fromthe selected 835 peer-reviewed articles. We evaluate empirical studies of decoupling related tofinal/useful energy, exergy, use of material resources, as well as CO2and total GHG emissions. WefindthatrelativedecouplingisfrequentformaterialuseaswellasGHGandCO2emissionsbutnotfor useful exergy, a quality-based measure of energy use. Primary energy can be decoupled fromGDP largely to the extent to which the conversion of primary energy to useful exergy is improved.Examples of absolute long-term decoupling are rare, but recently some industrialized countrieshave decoupled GDP from both production- and, weaklier, consumption-based CO2emissions.We analyze policies or strategies in the decoupling literature by classifying them into three groups:(1) Green growth, if sufficient reductions of resource use or emissions were deemed possiblewithout altering the growth trajectory. (2) Degrowth, if reductions of resource use or emissionswere given priority over GDP growth. (3) Others, e.g. if the role of energy for GDP growth wasanalyzed without reference to climate change mitigation. We conclude that large rapid absolutereductions of resource use and GHG emissions cannot be achieved through observed decouplingrates, hence decoupling needs to be complemented by sufficiency-oriented strategies and strictenforcement of absolute reduction targets. More research is needed on interdependencies betweenwellbeing, resources and emissions.