Hydropower not sustainable either ...

Large hydropower dams 'not sustainable' in the developing world

Sobering article. I had thought that the large amounts of concrete would account for some CO2, but the greenhouse gas emissions from decaying organic matter in the flooded areas had not occurred to me. Scratch that one off the list then.

But another thing that caught my eye was the suggestion that there should be more investment in solar, wind and biomass. A friend was posting some basic arithmetic of population density on FB. I could not find a mistake in his sums, and the conclusion is that with a world population approaching 8 billion, if we take land area of the Earth, minus the uninhabitable mountain, desert and polar regions, you have just one hectare per person (locally in the UK, it would be a lot less). One hectare per person must supply:

Living space
Employment space
Recreational space
Some for infrastructure
Food production
Plants for natural fibres for clothes and other fabric
Space for solar panels, if used
..probably a lot I've forgotten

+ Space to grow biomass fuel ? It won't be enough. Even if we don't leave any space for wildlife.

Food for thought, indeed, CH. It is to be hoped that there's 'someone out there' who can come up with a sustainable solution.

Don't put all your eggs in one basket is what springs to mind. All energy sources are going to be damaging or depleting in some way either directly or indirectly - you can't take something without it having an impact. Perhaps using many different energy sources on a smaller scale would give a better chance to restrict damage and allow for repair and replacement.