With enough energy almost anything can be done. The most extreme example I go to is solving adverse effects of climate change on crops: simply build giant green

With enough energy almost anything can be done. The most extreme example I go to is solving adverse effects of climate change on crops: simply build giant greenhouses - you have the energy to power artificial sunlight, desalinate water, etc. With that in mind, this isn't the sort of lead you could easily (or even reasonably) catch up to. The manner in which an energy superpower would operate would be completely alien to compared to what we know today. China will come to economically dominate the planet unless America (or some another country) catches a wake-up call. High speed rail is a convenience by comparison.