"Walking does more than driving to cause global warming..."

Another paean today to the Law of Unintended Consequences, or as I've said it before: It Ain't Easy Being Green. The gentleman saying it here today is Dominic Kennedy who noted in last week's Times that "Walking does more than driving to cause global warming, a leading environmentalist has calculated." How 'bout that! Here's the argument behind the calculation:

Food production is now so energy-intensive that more carbon is emitted providing a person with enough calories to walk to the shops than a car would emit over the same distance. The climate could benefit if people avoided exercise, ate less and became couch potatoes. Provided, of course, they remembered to switch off the TV rather than leaving it on standby.

The sums were done by Chris Goodall, campaigning author of How to Live a Low-Carbon Life, [described by New Scientist as "the definitive guide to reducing your carbon footprint"] based on the greenhouse gases created by intensive beef production. "Driving a typical UK car for 3 miles adds about 0.9 kg of CO2 to the atmosphere," he said, a calculation based on the Government's official fuel emission figures. "If you walked instead, it would use about 180 calories. You'd need about 100g of beef to replace those calories, resulting in 3.6kg of emissions, or four times as much as driving.

"The troubling fact is that taking a lot of exercise and then eating a bit more food is not good for the global atmosphere. Eating less and driving to save energy would be better."

Mr Goodall, Green Party parliamentary candidate for Oxford West & Abingdon, is the latest serious thinker to turn popular myths about the environment on their head.

Catching a diesel train is now twice as polluting as travelling by car for an average family, the Rail Safety and Standards Board admitted recently. Paper bags are worse for the environment than plastic because of the extra energy needed to manufacture and transport them, the Government says.

Fresh research published in New Scientist last month suggested that 1kg of meat cost the Earth 36kg in global warming gases. The figure was based on Japanese methods of industrial beef
production but Mr Goodall says that farming techniques are similar throughout the West [although obviously not all the west].

What if, instead of beef, the walker drank a glass of milk? The average person would need to drink 420ml - three quarters of a pint - to recover the calories used in the walk. Modern dairy
farming emits the equivalent of 1.2kg of CO2 to produce the milk, still more pollution than the car journey.

Cattle farming is notorious for its perceived damage to the environment, based on what scientists politely call "methane production" from cows. The gas, released during the digestive
process, is 21 times more harmful than CO2 . Organic beef is the most damaging because organic cattle emit more methane.

Michael O'Leary, boss of the budget airline Ryanair, has been widely derided after he was reported to have said that global warming could be solved by massacring the world's cattle. "The
way he is running around telling people they should shoot cows," Lawrence Hunt, head of Silverjet, another budget airline, told the Commons Environmental Audit Committee. "I do not think you can really have debates with somebody with that mentality."

But according to Mr Goodall, Mr O'Leary may have a point. "Food is more important [to Britain's greenhouse emissions] than aircraft but there is no publicity," he said. "Associated British Foods isn't being questioned by MPs about energy.

"We need to become accustomed to the idea that our food production systems are equally damaging. As the man from Ryanair says, cows generate more emissions than aircraft. Unfortunately, perhaps, he is right. Of course, this doesn't mean we should always choose to use air or car travel instead of walking. It means we need urgently to work out how to reduce the greenhouse gas intensity of our foodstuffs."

Simply cutting out beef, or even meat, however, would be too modest a change. The food industry is estimated to be responsible for a sixth of an individual's carbon emissions, and Britain may be the worst culprit.

Interesting stuff, no? Kennedy finishes up with a grab bag of eco-myths that he takes to with relish:

• Traditional nappies are as bad as disposables, a study by the Environment Agency found. While throwaway nappies make up 0.1 per cent of landfill waste, the cloth variety are a waste of energy, clean water and detergent.
  
• Paper bags cause more global warming than plastic. They need much more space to store so require extra energy to transport them from manufacturers to shops.
• Diesel trains in rural Britain are more polluting than 4x4 vehicles. Douglas Alexander, when Transport Secretary, said: “If ten or fewer people travel in a Sprinter [train], it would be less environmentally damaging to give them each a Land Rover Freelander and tell them to drive.”
  
• Burning wood for fuel is better for the environment than recycling it, the Department for Environment, Food and Rural Affairs discovered.
  
• Organic dairy cows are worse for the climate. They produce less milk so their methane emissions per litre are higher.
  
• Someone who installs a “green” lightbulb undoes a year’s worth of energy-saving by buying two bags of imported veg, as so much carbon is wasted flying the food to Britain.
  
• Trees, regarded as shields against global warming because they absorb carbon, were found by German scientists to be major producers of methane, a much more harmful greenhouse gas.

The moral of the story? It's not easy appeasing Gaia. Or trying to.