Our sustainable future

摘要

The price of a cup of coffee. That's one estimate of what it will cost each American every day for the next 20 years to break the fossil fuel habit of generations and turn to renewables instead. A daily outlay of a shade under a couple of dollars does add up to trillions over the decades, but is it really that much to ask? To prevent dangerous climate change, levels of carbon dioxide in the atmosphere need to be cut by 80 per cent by the middle of the century - and that's relative to 1990 levels. It will be a huge undertaking, but both candidates in next month's US presidential election acknowledge that the world's biggest polluter will have to change its tune if others are going to play their part (see page 12). The UN says the renewable energy that can already be harnessed economically would supply the world's electricity needs 15 times over (see page 28). As yet only a tiny proportion of electricity is generated this way, but replace existing coal, gas and oil-fired power stations with renewables and you achieve a colossal environmental win.rnThere's a bonus, too. Renewable energy breaks nations' dependence on imported sources, and this has brought its traditional, mainly Democratic, supporters in the US some unexpected allies. The Texan oil tycoon and long-time Republican supporter T. Boone Pickens wants to build the world's biggest wind farm in Texas. Former CIA chief James Woolsey is now a vocal advocate of renewables on the grounds of national security. And while many Republicans remain ambivalent, a handful of the party's senators now publicly back the idea.