Ethanol cars unhealthier than petrol ones?

Quixotic Californian boffin favours windmill-powered motors

An American academic has published research (pdf) suggesting that bio-ethanol vehicles could be more damaging to human health than ordinary fossil-fuelled ones.

Mark Jacobson of Stanford University in California used two computer models to predict American air quality in the year 2020. In the first scenario, it was taken that all vehicles ran on petrol. In the second, it was assumed that the motors would instead use E85 – a mix of 85 per cent ethanol and 15 per cent petrol.

Jacobson found that the E85-driven model forecast 200 more deaths per year across the USA, the majority occurring in Los Angeles. The extra deaths would occur in places where the amount of surface-level ozone could be expected to increase as a result of ethanol use. There would be other places where ethanol vehicles would actually reduce the amount of ozone present, but overall the health consequences would be negative.

Ozone, the triple-atom oxygen molecule, is vital for human health when found high above the earth's surface as it absorbs harmful UV radiation. But when breathed in too-high concentrations, it can trigger asthma attacks and other respiratory problems.

"We found that using E85 will cause at least as much health damage as gasoline, which already causes about 10,000 premature deaths annually from ozone and particulate matter," said Jacobson.

"The question is, if we're not getting any health benefits, then why continue to promote ethanol and other biofuels."

Another way of looking at those figures, of course, is that the sims showed a two per cent difference between deaths from petrol and deaths from ethanol. Most of that variance was the result of a cluster in LA, a region for which Jacobson seems to have used a different sim structure than he did for the rest of the States. Just how statistically significant all this is could be open to debate, especially as E85 advocates would point out that ethanol could potentially be carbon-neutral one day – unlike petrol.

However, we can probably acquit Jacobson of being in the oil industry's pocket. His plan is for windmill-powered cars. The BBC quotes him as saying:

"Converting all vehicles to battery-electric, where the electricity is from wind energy, would eliminate 10,000 air pollution deaths per year and 98 per cent of carbon emissions from vehicles."

Some would suggest, of course, that all the windmills you can practicably build won't even power existing electricity demand – let alone produce enormous amounts more juice with which to charge up vehicular batteries. Greenpeace, for example, issued a report (pdf) last September in which they estimate that wind can provide "a third of the world's electricity", by "the middle of this century".

If the hippies are right, Jacobson's plan would not be viable. There are also other issues with battery vehicles, most notably that they need to spend nearly as much time charging as they do on the road. As their range is currently no better than liquid-fuelled cars, this rules them out of many longer-haul road applications at present.

Still, just as there may not be enough wind for Jacobson's plan, there might well not be enough farmland and biomass to run transportation on carbon-neutral ethanol either – not if we also want to eat, anyway, and surely not if the whole planet is to develop US or European-style transport infrastructure.

It could be that Jacobson's battle against the ethanol lobbyists is ultimately irrelevant, as neither party seems to have a complete solution. On the face of it the human race will continue to need power sources with more potential than any kind of renewable tech, certainly if any large proportion of people are to achieve lifestyles even close to those of today's affluent Westerners. At the moment most of our power comes from burning hydrocarbons, but even hardcore global-warming deniers admit that the fossil fuel supply is finite.

The gorilla in this particular room may be a nuclear one. ®