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Editorial–

SINCE George W. Bush pledged a major US

effort to develop biofuels in his State of the

Union address earlier this year, it seems the

whole world has joined the rush to convert

corn, sugar, cassava, sorghum and palm

oil – not to mention cooking fat and farm

waste – into the fuels of the future.

From China and Indonesia to India and

Cuba, everyone wants to turn crops into energy.

The European Union is even considering a

mandatory 10 per cent biofuel content at

every pump. The dream is to cut reliance on

fossil fuels while also reducing net greenhouse

gas emissions and even helping hard-pressed

farmers. And yet, there is a downside to all this.

With today’s biofuel technologies, filling

fuel tanks this way would require a huge

amount of land – enough to transform the

world’s agriculture (see page 36). The prospect

of growing corn to make ethanol is already

helping to push up global grain prices and

reduce emergency food stocks. Areas

earmarked for palm oil biodiesel production

in south-east Asia threaten to finish off the

region’s surviving rainforests.

What’s more, a rash of studies suggests that

the greenhouse gains from biofuels are far less

than commonly assumed. True, the carbon

emitted by burning biofuels is absorbed by

the next crop as it grows, but manufacturing

the fertilisers and pesticides needed to grow

most biofuels requires large amounts of

energy, as does turning the product into fuel.

The net emissions reductions compared with

conventional fossil fuels are often small – little

more than 10 per cent in the case of corn,

Bush’s biofuel of choice.

Does this mean that biofuels are a wasted

cause? Certainly not. The good news is that the

technology is only just getting started. The

trick will be to find ways to use plants that

grow well without a sea of chemicals, and to

process them more efficiently. We shouldn’t

dismiss all biofuel projects until each new

technology is up and running. Modest use of

biofuels today is perfectly acceptable and

passably green – for instance, there are few

downsides to converting used cooking oil into

biodiesel, recycling farm waste or growing

biofuels on disused land.

The key here is caution. Research into

advanced biofuels has been starved of funds

for decades. It is at a very early stage and may

one day deliver, so we must give it time to

mature. Meanwhile, we cannot grow our way

out of the twin crises of climate change and

energy security. There is a real danger of

creating a biofuels bubble that will burst,

leaving behind a pungent whiff of chip-fat oil,

burning rainforests and rotting fields. ●

THE idea that what we eat affects our health

is deeply ingrained in our collective

consciousness. Most people know that the

wages of dietary sin are a slew of diseases

including obesity, cancer, heart disease,

diabetes and osteoporosis. The World Heath

Organization, too, sees unhealthy eating

as a major problem. It estimates that

non-communicable diseases will account for

75 per cent of all deaths worldwide by 2020,

and considers an unhealthy diet to be one

of the main causes.

That’s all very well, but what actually

constitutes a healthy diet? Obesity-inducing

gluttony aside, it’s surprisingly hard to say.

When nutrition researchers have attempted

to find definitive links between diet and

health, all too often they have drawn a blank

(see page 42). There are many reasons for

this, such as flawed study designs and the

difficulty in getting research subjects to stick

to a particular regime. But there is another

possibility that researchers seem strangely

reluctant to consider: that there are no strong

links between diet and chronic diseases.

While that seems unlikely, it is a possibility

that nutrition researchers ought to entertain.

If it were true, it would be something worth

knowing. At the very least it would suggest

that the magnitude of dietary changes

required for a person to significantly reduce

their risk of disease are simply too great to

maintain in the long run. Then we could all

stop worrying about what we’re eating and

focus our energies on lifestyle changes that

have a genuine chance of succeeding –

stopping smoking, cutting down on alcohol

and taking more exercise. ●

Who says diet is the key to beating disease?

www.newscientist.com 23 September 2006 | NewScientist | 3

A paler shade of greenBiofuels may be less than perfect, but they’re still worth a shot

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