ABSTRACT
Within the UK and the EU there is broad political agreement that we should make our fair contribution to avoiding dangerous climate change. In the absence of any explicit global consensus on an appropriate metric for delineating dangerous from acceptable climate change, European leaders have frequently reiterated their commitment by suggesting the EU takes the lead internationally to “ensure that global average temperature increases do not exceed pre-industrial levels by more than 2°C”.1 The UK 2006 Climate Change Programme,2 the 2006 Energy Review3 and the 2003 Energy White Paper4 all serve to underline the UK Government’s commitment to the importance of the 2°C threshold. The link between a global temperature threshold, such as 2°C, to a national or regional carbon emission pathway is partially value-driven (e.g., through choosing a method of apportioning global emissions to regions or nations) and is further complicated by a range of scientific uncertainties (e.g., climate sensitivity). Nevertheless, understanding the link is useful when considering appropriate national and regional carbon-reduction strategies. This chapter will focus on understanding the consequences for climate policy of establishing a target of a 2°C global temperature rise for the global, EU and UK scales. It will then focus on emission apportionment for the purpose of forming regional and national climate change targets, with results presented for both an old and new interpretation of apportioned emission pathways for the EU and UK.
