Common Urban Myths About Transport

Myth: Alternative fuels will come to the rescue

Fact: Many alternative fuels do nothing to fix local air pollution, merely substituting one noxious chemical for another. Others such as natural gas or ethanol are impossible to produce on the scale required. This leaves electricity and hydrogen, but as these are energy carriers rather than fuels they must themselves be produced using some other fuel, which just pushes the problem up one level.

The road lobby itself never denies that cars do a lot of damage to the environment through the pollution and carbon dioxide they generate. But they tell us not to worry, because we are only a few years away from technological solutions that will make cars truly environmentally friendly. Next to the usual fairy tales about improving fuel efficiency, their favourite argument is that new 'green' fuels, already under development, will replace petrol and render pollution and greenhouse emissions a thing of the past.

A Fuel's Paradise

The quixotic quest for the new miracle fuel that will surpass petrol, and be cheap and plentiful to boot, has been with us for at least half a century. In the 1950s, cars powered by personal nuclear reactors capable of travelling thousands of kilometres on a handful of uranium were supposed to be on the verge of becoming a reality. In the 1970s solar cars were just around the corner, and in the 1990s the next big thing was running cars on used cooking oil - assuming you could get it in the quantity required. Still no challenger has risen with serious prospects of toppling the dominance of petrol and diesel.

On the margins, LPG conversions are becoming popular as a way to avoid high petrol prices (and have now got a boost courtesy of the Howard Government), but the efficiency benefits should not be overstated: as the following table shows, the average LPG-fuelled car has only about 3 per cent less CO₂ emissions than the average petrol-fuelled car, and is slightly less energy efficient.

Fuel efficiency and emissions by fuel type
	Petrol	Diesel	LPG
Fuel consumption (l/100km)	12.0	11.5	17.2
Energy density (MJ/l)	34.2	38.6	25.7
Energy consumption (MJ/km)	4.10	4.44	4.42
CO₂ emission factor (g/MJ)	66.0	69.7	59.4
CO₂ emissions (g CO₂/km)	271	309	263

Source: Australian Greenhouse Office. Australian Methodology for the Estimation of Greenhouse Emissions and Sinks 2002. Fuel consumption figures are based on fleet averages. Emissions from the fuel supply chain are excluded.

But even if the new miracle fuel became available tomorrow, along with cars capable of running on it, it would still take many years before most vehicles on the road used the new fuel. This was seen with the introduction of unleaded petrol in 1986; after 15 years there were still many pre-1986 vehicles on the road, hence the need to distribute 'lead replacement' petrol extensively when leaded petrol was finally phased out. And this was a relatively minor technology shift, so the technology could be made available in all new vehicles from 1986 onward for very little additional cost.

Changing to an entirely new fuel source is a much larger technological leap, so even when new fuel technology becomes commercially viable it will take some time before it accounts for even a significant minority of new vehicle sales. Thus, while cars with hybrid petrol/electric engines have been on the market now for some years, their higher price tag and doubts about their performance have kept their market share low.

[Industry analyst Felix Kuhnert] said attempts by car makers to persuade people to buy more environmentally friendly cars were failing in the showroom, where financial considerations always beat environmental ones. He said 31% of drivers surveyed said they would consider purchasing a hybrid car as their next vehicle, but that figure dropped by two-thirds if the purchase price was higher. Only 6% of those questioned would consider purchasing a hybrid car if the price premium was more than 2000 euros [about $A3000].
---Money rules the road to a green car, The Age, 6 March 2008

Substituting One Problem For Another

The real difficulty with alternative fuels is, however, the same as with any attempt to treat the symptoms instead of the cause of a problem: the fundamental problem doesn't go away but instead lingers to cause more difficulties later on. Any hydrocarbon fuel when burnt in air, whether it be petrol, diesel, biodiesel, LPG or ethanol, produces both carbon dioxide and noxious byproducts such as nitrogen oxides and ozone. Of course they differ in degree: diesel and biodiesel produce lower sulphur emissions than petrol, but produce more particulate matter (soot) which is associated with higher rates of lung disease; ethanol may or may not reduce net carbon dioxide emissions (depending on where it comes from) but increases emissions of ozone and of formaldehyde, a highly toxic organic solvent. Even the lowest-emission fuels, LPG and natural gas, can often produce as much or more carbon monoxide and nitrogen oxides than petrol (and are also much more limited in supply). And just as with the claim that free-flowing traffic cuts pollution, any overall reduction in pollutants is soon cancelled out by the sheer growth in car and truck trips.

The only 'fuels' that do not produce local pollution are electricity and hydrogen. But these are not fuels so much as energy carriers; they do not occur naturally but instead must be generated from some other, naturally-occurring energy source. In practice electricity in Australia will continue to be sourced mainly from coal for a while yet, while hydrogen is today most commonly produced by 'steam reforming' of hydrocarbons, which generates carbon dioxide as a byproduct. As a result, use of electric or hydrogen-powered cars will not reduce greenhouse emissions, and may even increase them. While it is possible to imagine that at some time in the future we may be able to use electricity or hydrogen piped from massive solar collectors in the desert, it is unlikely to be either as cheap as petrol per kilometre driven, or to be available in such large quantities.

The next day, I got a look at the Hydrogen 7.... The car is very nice. But does it make environmental sense? The simple answer is no. In the context of the overall energy economy, a car like the Hydrogen 7 would probably produce far more carbon dioxide emissions than gasoline-powered cars available today. And changing this calculation would take multiple breakthroughs--which study after study has predicted will take decades, if they arrive at all. In fact, the Hydrogen 7 and its hydrogen-fuel-cell cousins are, in many ways, simply flashy distractions produced by automakers who should be taking stronger immediate action to reduce the greenhouse-gas emissions of their cars.
---David Talbot, Hell and Hydrogen, Technology Review, March/April 2007

These same caveats apply also to more exotic, enthusiastically promoted alternatives such as compressed air, flywheels and hydraulic fluid. The energy always has to come from somewhere, and the available sources are either expensive, scarce or environmentally damaging. For example, though compressed air is commonly regarded as a 'free' energy source (it's just air!), most air compressors are only 10 to 20 per cent efficient, losing the bulk of their energy input as heat or through leakage. So every unit of energy stored in compressed air has required another 4 to 5 units just to produce.

It also has to be remembered that even pollution-free cars and trucks would still crash just as often, take up just as much land for roads, and generate the same equity problems as they do today. There truly is no 'free lunch' when it comes to solving the problems with car transport.

Petrol From Coal?

One of the scarier suggestions to emerge from the fuel price hikes of 2005 is that we hasten climate change by using liquefied coal as a replacement for petrol and diesel. Although this is feasible with current technology (indeed, the Germans did it during both World Wars), it is still too inefficient and expensive to be commercially attractive. And because to liquefy coal one essentially has to remove the 'excess' carbon from it, thereby generating carbon dioxide, we would actually wind up generating CO₂ even faster than we currently do by pumping oil and burning it in car engines.

According to industry figures obtained by the University of Technology, Sydney, the use of liquid fuel derived from Victorian brown coal would generate more than double the greenhouse emissions of ordinary petrol (182g CO₂/MJ compared with 84g CO₂/MJ). The liquefication plant alone would have eight times the emissions of a conventional oil refinery. This would be a huge backward step in the search for sustainable energy.

Nonetheless, the very same Victorian Government that refuses to spend money on new rail extensions is now backing a $5 billion project to convert coal into transport fuel. The success of the project relies on being able to pump the excess CO₂ underground, an unproven technique that so far no-one has got to work reliably despite all the breathless PR that has been devoted to it:

VICTORIA could lead the world in turning coal into transport fuel after multinationals Royal Dutch Shell and Anglo American made Melbourne-based joint venture Monash Energy their top global research priority.... New Victorian Energy Minister Peter Batchelor has met Monash Energy executives twice this week to discuss the coal-to-liquids project....
The project is expected to cost $5 billion and Monash Energy plans to produce commercial quantities of diesel fuel by 2016. As part of its geosequestration plan, the Victorian Government plans to build a pipeline from the Latrobe Valley to a carbon dioxide storage facility. Access to this pipeline, which the Government has dubbed a "CO2 hub", would be open to energy producers and industry to dispose of carbon dioxide emissions.
---Batchelor meets Anglo on coal venture, The Age, 9 February 2007

The Biofuel Red Herring

Finally there are the now vigorously-promoted schemes to actually 'grow' the fuel for our cars by planting crops, digesting the crops to produce biofuel, running cars with the biofuel and using the carbon dioxide emissions to grow a new crop. While superficially attractive, these schemes suffer from the same problem as schemes to plant trees to soak up carbon emissions: the sheer scale of our driving habits makes them unviable. Converting the entire Australian wheat crop to ethanol production would, for example, only substitute for around 15% of Australia's oil consumption. There are many similar findings:

CSIRO scientist Barney Foran estimated in 2000 that fuelling the Australian vehicle fleet with methanol derived from trees (the most dense bio-energy source available) would require 30 million hectares of plantation. But as we explain on the page linked just above, there are at most about 9.6 million hectares available in all of Australia for plantation farming (and even this assumes an over tenfold increase in the use of land for plantations).
In 2003, Jeff Dukes of the University of Utah estimated that the world each year burns up fossil-fuel energy equivalent to 400 years of global plant growth.
According to a statement by the US Department of Energy in 2006, to replace 30% of US petrol supplies with ethanol would require 60 billion gallons of ethanol a year, while all the corn currently grown by US farmers could make just 18 billion gallons a year.
London analyst David Jackson calculated in 2007 that blending just 5% biofuel into all the world's cars would require an additional 100 million hectares of farmland. This is about equal to the remaining land available for farming on Earth, much of which is uneconomic to develop.

Biofuel schemes, then, can only possibly work in conjunction with policies to substitute environmentally friendly transport for car and truck trips.

Meanwhile there are increasing doubts whether the production and use of biofuels really has a net positive greenhouse impact at all. Although it seems obvious that biofuel crops should soak up roughly the same amount of carbon dioxide when growing that they give off when burned, there are other factors that intrude on the process. The biggest of these is that the crops rely on fertilisers that produce significant emissions of nitrous oxide (N₂O), a greenhouse gas 300 times as potent as carbon dioxide. A 2007 paper by Nobel laureate Paul Crutzen concludes that biofuel crops can cause as much global warming via N₂O as they save in CO₂ from displaced fossil fuels. Then, there is the tendency for biofuel crops to be grown on cleared peatland or rainforest land in countries like Indonesia or Brazil. Clearing a rainforest removes a carbon sink more significant than a biofuel crop, while draining a peatland releases enormous quantities of stored CO₂. Together, all these effects wipe out the emission savings from use of the harvested biofuel. According to two studies independently published in the journal Science in February 2008, almost all current biofuel production is causing more greenhouse emissions than conventional fuel use.

Last but not least there is the rather nasty side-effect, that using 'energy crops' for fuel competes directly with food supplies. The Earth Policy Institute in the US estimates that the grain required to fill one 25 gallon (95 litre) fuel tank would feed one person for a year. The US already uses nearly one-sixth of its grain crop (and over half of all its corn) to produce ethanol for cars, and while this represents only 3% of all fuel sold, it is starting to affect the global prices of wheat and corn, which feed into other food prices. (The price of one corn variety increased 45% in 2006 alone.) Brazil meanwhile uses its extensive sugar cane crops to make ethanol (much of them on cleared Amazon rainforest), and this has been a factor in the world price of sugar trebling between 2004 and 2006. According to a paper in the Proceedings of the National Academy of Sciences in the USA, it would be impossible for ethanol to significantly replace petroleum without a serious impact on food supplies.

Corn has about doubled in price during the last few months, thanks to an increasing demand for ethanol.... [t]he higher corn prices.... mean that [dairy farmer David] Kyle has to pay almost double this year for the corn feed he gives his cows. Kyle says he may well have to reduce his herd, which means there'll be less milk produced because of the price of corn. That's the bottom line.....
Almost everything in our refrigerator contains corn, says Lester Brown of the Earth Policy Institute. Whether it's milk or eggs or chicken, pork, beef, ice cream, yogurt - these are all corn products. And consider this: The price of wheat, soybeans and other crops will go up because farmers will be planting less of each.
---As Cars Go Green, Food Prices Will Jump, ABC News (USA), 9 April 2007

In the 1850s, the great Irish Potato Famine resulted when wealthy consumers bid up the price of scarce potatoes, so that poor people could no longer afford to eat. A similar threat exists to those in developing countries today if ethanol and biodiesel become significant fuel sources for affluent motorists. This is not just alarmist speculation: in all but one year this century the world's consumption of wheat has exceeded production, and in 2007 global wheat stocks were at their lowest level since 1972. According to New Scientist in April 2007, industry insiders are concerned about the recent emergence of new resistant varieties of old crop diseases like black stem rust; meanwhile, Australia's own wheat production is threatened by drought. We cannot be complacent any longer about the world's capacity to produce staple crops.

What we're beginning to see is a sort of epic competition emerging in the world between the 800 million people who own automobiles and the 2 billion poorest people in the world who are now beginning to compete for the same grain supplies. We've never faced a situation like this before.
---Lester Brown, Earth Policy Institute, April 2007

Further confirmation has come from the OECD (hardly the world's most ardent greenies) who in 2007 weighed in with its own assessment, stating in its own way the same conclusions drawn by others.

The OECD considers the bioenergy industry to become a key factor in the functioning of agricultural markets. Food prices are expected to rise between 20% and 50% over the next decade.... consistent with the development of food prices in recent years that have gone up sharply in reaction to increased biofuel production in Brazil...., China, the EU and the United States....
The assumption [has been made].... that competition between food and biofuels can be avoided. In reality, energy cropping on dedicated land is in competition with food production as of day one....
The current push to expand the use of biofuels is creating unsustainable tensions that will disrupt markets without generating significant environmental benefits.... Governments should cease creating new mandates for biofuels and investigate ways to phase them out.
---Organisation for Economic Co-operation and Development. Biofuels: Is the Cure Worse Than the Disease?, September 2007.

The Celsias Blog has compiled a useful round-up of the evidence on unintended consequences of biofuel promotion.

Conclusion

In its investigation of all the options, the British Royal Commission on Environmental Pollution concluded that

there would not be any environmental advantage in widespread use of alternative fuels in the UK.

And the economically-dry OECD concurs, even going as far as to say it is more important to reduce demand for fuel instead:

The demand side of the transport fuel problem should receive proportionally more attention than the supply side. A litre of gasoline or diesel conserved because a person walks, rides a bicycle, carpools or tunes up his or her vehicle's engine more often is a full litre of gasoline or diesel saved at a much lower cost to the economy than subsidising inefficient new sources of supply.
---OECD, Biofuels: Is the Cure Worse Than the Disease?

There is certainly a limited role for some alternative fuels in particular contexts; Paul Mees notes in A Very Public Solution that use of compressed natural gas instead of diesel in vehicles that stop frequently in urban areas, such as buses and garbage trucks, would help put these essential services on a more sustainable footing. (Though even here caution is required: the spark-ignition engines that burn gaseous fuels are less efficient than diesel engines.) In the final analysis, the use of alternative fuels will have at best a marginal benefit, and will have no benefit at all unless accompanied by a substantial switch from car trips to public transport, walking and cycling.

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© 2007 Public Transport Users Association Inc. (PTUA), Victoria, Australia. ABN 83 801 487 611.
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Last modified: 6 March 2008