Many countries are facing serious challenges as a result of the lingering global economic crisis. At the same time, all nations share a responsibility to ensure their energy sectors become more sustainable and more secure to manage the risks and impacts of climate change. Over the coming decades, energy efficiency, many forms of renewable energy, carbon capture and storage (CCS), nuclear power, new transport technologies and more efficient use of fossil fuels will all require widespread deployment. The need for action is urgent, but drastically changing energy infrastructure and end-use equipment on a national scale is a complex and expensive undertaking. Careful planning is required to ensure that limited resources are devoted to the highest-priority, highest-impact actions in the near term while laying the groundwork for longer-term improvements.