In reply to wintertree:
really? 3m deaths annually because previous generations didn't 'max out' on exploiting hydro power in the developed world?
surely not. i'd have thought the incremental difference between the total global deaths annually attributed to climate change and pollution from fossil fuel burning, and the total had some high profile hydro schemes which were cancelled in order to protect key wild land gone ahead, would be hard to measure, but would be much much less than that.
and even then it is only one part of the equation- the amazon rain forest is one of the biggest carbon sinks on the planet. the annual flooding inundates an area the size of the UK and allows nutrients to be delivered to the forest. without that, there may be serious damage to the integrity of the forest, and loss of its ability to act to offset CO2 from fossil fuels, which as you rightly point out, look like they will be exploited to the last drop irrespective of the consequences
the blanket damming of the amazon is far from a consequence free alternative to burning fossil fuels; it is likely just to swap one set of potentially catastrophic consequences for another, with more obvious immediate devastation to the locations of the damming.
in the end you are right; unless fusion saves us it is hard to see how energy demands of future generations can be met, irrespective of how many dams are built.
but humans don't operate on a purely abstract cost/benefit analysis of the value of energy policies. wild land is important to the human psyche, and you are too dismissive of the importance of the UK's wild land to our wellbeing. nor is this a purely western phenomenon; having spoken to chileans, peruvians and argentinians, many are aware of the global importance of their landscapes, and justifiably proud of them. other nations find spiritual significance in their wild areas. these landscapes provide value, inspiration, and meaning to people.
so in the meantime, while we hope for fusion to save our bacon, preserving certain iconic landscapes and features, to inspire future generations, while accepting we have to develop others, looks like a balanced way forward. and in any analysis of what counts as a globally important landscape worthy of protection, the main source of the greatest river in the world, as it passes through unspoiled canyons 10000 ft deep, and still provides a home for the original inhabitants of the regions, surely counts as one,
best wishes
gregor
Post edited at 16:34