ambitious climate targets. It has also been shown that
limiting climate change will undoubtedly require major
changes to the global energy system, which takes the form
of extensive deployment of new and existing low-carbon
technologies [1,7–9]. Thus the availability of technology has
the effect of shaping the optimal time path of emission
mitigation, that is, the relative degree of near-term and
longer-term emission reductions, which in turn influences
the cost of achieving the climate targets [4,8].