Both tidal and geo-thermal are untried technologies and have significant environmental implications in their own right.  It also seems highly unlikely that deploying nuclear as a ‘bridge’ technology would be anything like that, certainly the history of energy production does not suggest that industries are likely to plan for their own extinction in favour of more environmentally sensitive technologies.  This is especially true of nuclear power; it simply is not a short-term technology as the reprocessing and containment schedules are enormous. A decision to use nuclear even for a matter of decades would have implications that would run for longer than the history of human civilization to date.  Wind, by contrast, is a developed technology that has no implications for future generations.