The subject of climate change is imbued with scientic dissensus on what precisely is happening, and will happen, with the climate. Part of this dissensus is related to the large uncertainties associated with climate simulation discussed in Chapter 6. Furthermore, there is disagreement on political objectives vis-à-vis anthropogenic climate change (e.g., To what extent do we want to limit anthropogenic interference with the climate system? What should we do to mitigate the likely causes of climate change? To what extent should we prepare to adapt to it?). Perceptions of the climate-change risk vary widely both across the globe and within societies. Thus, the uncertainties are largewith climate simulation being a signicant contributor to these uncertainties-and the stakes are high. This puts the problem of anthropogenic climate change in the category of ‘unstructured’ policy problems that are in need of a ‘postnormal’ problem-solving strategy (see Chapter 4).