Climate change will be an ecological and humanitarian catastrophe unless we move quickly to eliminate greenhouse gas emissions. Policy experts advise us that we need to make major changes to our lifestyles, and our governments need to agree to globally binding treaties and implement market instruments like carbon taxes. This advice is a mistake: it treats technological innovation as being at the periphery of the climate policy challenge, whereas it needs to be at its core; we will phase out emissions when and only when the technologies to replace fossil fuels are good enough, and policies...