Workshop on GHG Stabilization Scenarios, 2004). Such targets can easily be inverted by carbon cycle models to determine the required emissions scenario for stabilization (e.g., Wigley, 1991). Cost-benefit scenarios are another approach. They are based on the premise that the most efficient policy intervention is that in which the marginal cost of reducing emissions is balanced by the marginal reduction in climate damages, measured in monetary terms (Cline, 1992).
Developing emissions scenarios is tantamount to asking how different societies will produce, transform, and consume energy; extract and use Earth’s resources; and modify the landscape for the next century. The possible answers to this vast and complex question are manifold. Uncertainties arise in all facets of the problem of building long-term scenarios. Moreover, unforeseen events, such as a revolutionary breakthrough in tech-