It may seem like an unusual topic for a PhD thesis in International Relations / Politics, but it seems to me like it could actually be a useful and interesting one.
The questions would be:
- What kind of standard of living could be supported for the world population using only renewable forms of energy?
- How quickly could that be deployed, given all the technical and political hurdles?
Ultimately, it is a very political question. The geopolitics of energy have already been front-and-centre for decades, since at least the 1973 oil price shocks. There is also the large and growing dependence of the European Union on Russia for gas, as well as increasing American dependence on exceptionally dirty oil from Canada.
The research could include investigation of places that have already deployed various renewables widely (hydro in Quebec, geothermal in Iceland, wind in Denmark, etc), as well as consideration of what is happening in rapidly developing states like China.
Thoughts? Suggestions?