When it comes to the problem of powering the global economy without fossil fuels, people sometimes point to completely new energy generation techniques as solutions. For example, space-based solar power and nuclear fusion.
While it is possible such technologies will play an important role in the long term, it is important to be realistic about both costs and timeframes for development and deployment. Excavation has just begun for the International Thermonuclear Experimental Reactor (ITER), in France. This machine, when completed, will be a prototype for a prototype for a commercial nuclear fusion power station. It is hoped that this device will teach scientists enough about controlled fusion to make a machine that could actually produce energy, rather than just consuming it by heating up fusion components and keeping them close together with powerful electromagnets. Achieving that will require a number of substantial technical advancements.
Contrast that with the kind of global emission pathway that is necessary to avoid 2°C of temperature increase, and thus ‘dangerous’ climate change. Given that little is happening in the United States, hoping for global emissions to peak by 2011 seems excessively optimistic. If they peak in 2020 – which would be a major achievement, requiring cooperation from developing states – the world would need to cut emissions to zero by 2040. It really doesn’t seem plausible that fusion could help with that, though it could play a role later on.
That said, there is some chance that somebody will find a way to achieve success with fusion more rapidly. It certainly makes sense to devote some fraction of our total research resources toward technologies that may be very promising in the long term. At the same time, we shouldn’t bet on breakthrough technologies solving our climate problem. We need to be ready to do it by improving and deploying existing technologies, while remaining open to the possibility that novel developments will end up making the process easier.
Physics buzz has more information on the current status of ITER.