Cities, particularly those in coastal areas around the world, need to pay close attention to the risks posed by global warming and climate change. These risks are substantial, and the costs of not taking them into account are likely to be enormous. Planners should take the lead in preparing climate mitigation and adaptation plans, although these need to be approached somewhat differently from other planning assignments. Adaptation planning, in particular, should be viewed as a collective risk management task. As such, new tools for collaboration such as scenario planning, joint fact-finding and the use of role-play simulations to build public support in the face of high levels of uncertainty and complexity might be helpful.