Keywords: atmospheric stabilisation targets, energy systems, technology change, timing of emissions reductions
The timing of CO2 emissions reductions: the debate revisited
Almost two years before the Kyoto conference, Wigley et al. (1996) published a paper that claimed not only that delaying emissions reductions would be compatible with eventual stabilization of atmospheric concentrations of CO2, but also that it would be less costly than early abatement. Four arguments were raised in favour of their conclusion. Nevertheless, in Kyoto, policy-makers decided to adopt near-term targets. In this paper, the arguments for and against deferral of emissions reductions are revisited. It is shown that these arguments can not be assessed in the absence of a discussion about the stabilization target. If a low stabilisation target is chosen, then early efforts to abate emissions are necessary, whereas a high stabilisation target (say 650 ppm) does not require much effort over the next couple of decades. Finally, a brief discussion of the way that the arguments in favour of delay were perceived in the policy-making community is provided.