I think the talk of alternative fuels is several steps in to a discussion that should really start much earlier in the process, as there are serious questions to ask about the fundamental justifications for the removal of fossil fuels, and the cost benefit analysis so far are seriously skewed.
The Dutch resolved the problem of sea level rises long before industrialisation, which raises a couple of interesting and very pertinent questions in itself. There actions resulted in an increase in fertile agricultural land, which they have benefited from ever since.
What rarely gets included in the debates are the many benefits fossil fuels have brought us, including increased life expectancy, better health, both of which are liable to be far greater than the losses predicted by the doom sayers, which are themselves very debatable. There is also the massive decrease in the loss of life and property from natural disasters that have been possible largely due to the technology made possible by fossil fuels.
I don't see much discussion on how ancient monuments are going to be kept maintained when the funding from tourism is removed, or how countries like Italy, Spain, Greece etc will replace the 10% of GDP they currently gain from tourism, nor how Governments are going to replace the lost tax revenue gained from fossil fuels.