Philip Ball in The Guardian:
There are plenty of uncertainties and unknowns around fusion energy, but on this question we can be clear. Since what we do about carbon emissions in the next two or three decades is likely to determine whether the planet gets just uncomfortably or catastrophically warmer by the end of the century, then the answer is no: fusion won’t come to our rescue. But if we can somehow scramble through the coming decades with makeshift ways of keeping a lid on global heating, there’s good reason to think that in the second half of the century fusion power plants will gradually help rebalance the energy economy.
Perhaps it’s this wish for a quick fix that drives some of the hype with which advances in fusion science and technology are plagued. Take the announcement last December of a “major breakthrough” by the National Ignition Facility (NIF) of the Lawrence Livermore National Laboratory in California. The NIF team reported that, in their efforts to develop a somewhat unorthodox form of fusion called inertial confinement fusion (ICF), they had produced more energy in their reaction chamber than they had put in to get the fusion process under way.