This chapter assesses the scenario literature for possible pathways that would achieve those targets, thereby closing the implementation gap (Table 21 2). The focus is on the question of what would be needed to achieve these targets – and what are important synergies and trade-offs between different measures and these targets. This chapter does not discuss the social or political feasibility of the pathways. Moreover, the focus is on measures (e.g. energy ef ciency improvement or changes in yield) and not on the policies to implement these measures (e.g. taxes or regulation).