I think it's possible to build enough renewable energy, but only if we reduce wasteful use of remaining fossil fuels (3). This will only work with the correct policies, like carbon and energy taxes, subsidies, and simply banning wasteful equipment and habits.

I'm afraid the only way to get the necessary policy changes is actually running into the next spike in oil and natural gas prices, Mexico stopping oil exports, a longer episode of Russia blocking gas-pipelines, even clearer evidence of climate change (ice-free Arctic, a few more Katrina's, persistent droughts, flooding, melting glaciers). To be sure, I don't want any of this to happen, but they will.

I just hope that this will lead to policy changes, and not to populist or even fascist regimes, eager to blame everybody else and willing to go to war for dwindling resources.