From long-term targets to cumulative emission pathways: Reframing UK climate policy

In March 2007, the EU reaffirmed its commitment to making its fair contribution to global mean surface temperatures not exceeding 2 °C above pre-industrial levels. In line with this, the UK Government has laid legal foundations for an emissions cut of 60% by 2050. Whilst 2050 reductions dominate the target-setting agenda, long-term targets do not have a scientific basis and are leading to dangerously misguided policies. If a policy is to be scientifically credible, it must be informed by an understanding of cumulative emissions and associated emissions pathways. This analysis of current UK climate policy illustrates how following the “correlation trail” from global temperature thresholds to national emissions pathways fundamentally reframes the UK's targets. Considering cumulative emissions, carbon cycle feedbacks and the omission of emissions from international transport dramatically increases both the scale and immediacy with which emissions need to be reduced; for example, within the UK, 6–9% p.a. reductions beginning as early as 2012. The implications of this are stark; society can no longer await the decadal timeframes necessary for a transition to low-carbon energy supply. If the 2 °C threshold is to maintain any meaningful currency, industrialised nations have little option but to radically and urgently curtail their demand for energy.