To cut your car’s carbon emissions, you could cycle instead of drive. Or trade your 3-litre monster in for something with a mosquito-sized engine; or, wait for it, you could put pap in your petrol tank. Leonie Joubert considers the brave new world of “green” fuel.

It’s the South African staple with many faces: sadza, umphokoqo, iphuthu, krummelpap, boiled mealie or braaied sweetcorn. Sometimes, it even arrives in a glass of umqombothi, with a kick as gentle as an unshod ass. That’s right, it’s maize, a local favourite. But this story starts in Mexico City, at the Great Tortilla Uprising of 2007.

Last summer, Mexicans took to the streets to protest a staggering 400 percent increase in the price of tortillas, the unleavened bread and national staple. The BBC reported that it was the most radical food price hike in decades. As usual, the poor stood to go hungry first.

Several things were pushing up food prices globally: growing demand; extreme weather slashed harvests in parts of the world; volatile oil prices sent fuel costs skyrocketing, which manifested as a shelf-price mark-up.

The United States, attempting to buffer itself against the vagaries of an up-again up-again oil price, was choosing to fill a percentage of the national fuel tank with maize. Specifically, ethanol made from the fermented sugars in maize as a substitute for petrol. As a result, the country was buying up vast amounts of the North American maize crop.

It’s a great idea, on the surface. Instead of looting ancient banks of fossil fuels, shunting their carbon stores up into the atmosphere via the furnace of your car’s engine, and thickening the roof of the global greenhouse, why not go “carbon neutral”? Take a mealie plant, which drew carbon from the atmosphere last summer while it grew, and burn it in your petrol engine, releasing its carbon back into the atmosphere. Round and round it goes in a neat, nearly-closed loop.

But it all boils down to food – because green fuels (biodiesel and bioethanol*) need traditional food crops. And in a world where global hunger is still on the rise, is it smart or even fair to take maize from one person’s dinner plate and, instead, use it to fill another’s petrol tank?

Our Department of Minerals and Energy has drawn up a biofuels strategy which appears to heed United Nations warnings about the risk to global food security – a plan which bans the use of maize for biofuel production. But this is really more about getting the former homelands into agricultural productivity than it is about securing food stocks.

Scientists are telling us that green fuels aren’t always as squeaky clean as ethanol salesmen would have us believe. Huge amounts of carbon are tucked away in topsoil – when you plough up virgin veld, you dump all that carbon straight back into the atmosphere, negating any benefits of using clean fuel grown in that ground.

So, sadly, it’s either risking your life in rush hour traffic on a bicycle; or the mosquito-engine car, because the maize solution has gone rather pap.

* The main types of “carbon neutral” or low carbon biofuels are biodiesel (where plant oil is blended with normal petroleum diesel) and bioethanol (made from the fermented sugars in maize, sugar cane and sugar beet as an alternative to petrol).

- Leonie Joubert

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