Edição Especial da NewScientist sobre Energias Renovaveis

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Special Report Climate Change

Editorial: How to run the world on renewables

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 "Feeling the Heat").

The UN says the renewable energy that can already be harnessed economically would supply the world's electricity needs 15 times over (see "Electric dreams"). 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.

There'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.

One long-standing objection to renewables - that wave and sun power can never be relied on for a steady supply, day in day out - is vanishing too as new ways to store energy are rolled out. The nuclear industry can no longer sell itself as the only reliable source of low-carbon baseload electricity.

Shifting the US to a predominantly renewable supply of electricity by 2030 would cost $4.4 trillion and would cut the nation's CO₂ emissions by 95 per cent, according to an estimate by internet giant Google. To put this in context, the $700 billion banking bailout attempt approved by Congress last week would already have paid for the first three years. A world run on renewables is no longer a hippy's fuzzy green dream. It's time we stopped arguing about its merits, and got on with making it a reality.

Energy and Fuels - Learn more about the looming energy crisis in our comprehensive special report.

From issue 2677 of New Scientist magazine, 08 October 2008, page 3