emissions

With all the excitement happening today at Terminal One, it's worth remembering that yesterday was another eventful one in Heathrow's calendar as a Virgin Atlantic plane steered away from its usual transatlantic route to fly between Heathrow and Amsterdam. No, the guidance systems weren't malfunctioning: it was a test flight to demonstrate that biofuels can be used in aircraft. But what's that dripping from the undercarriage? Could it be a tonne of greenwash?

Virgin announced its plans to test biofuels some time ago but has been reluctant to say exactly what kind of biofuel they would be using. To quell concerns about the impact on the cost of food, a press release assured us that it wouldn't "compete with food and fresh water resources". The rumour was that it would be made from algae, but in the end it turned out to be a mixture of coconut and babassu oil. These aren't food crops as such, but if the aviation industry leaps on them as an apparently easy way to reduce emissions, that's going to have a huge environmental impact.

London mayor Ken Livingstone was never going to get an easy ride over his planned changes to the congestion charge, and Porsche's threat of a legal challenge is perhaps no big surprise. Famed for its fast, sleek, inefficient cars, it claims the new £25-a-day charge on gas guzzlers is "unfair and disproportionate".

As well as the promised judicial review, the company has started a petition for the Jeremy Clarksons of this world to voice their opposition to Ken's plan. "We know that huge numbers of people in London and across the rest of the country support our case," they claim. "They agree with us that it would be bad for London - that it is unfair and sends the wrong message about what sort of a city London is whilst having no meaningful benefit on the environment."

My carbon footprint according to Defra

As I've been winding down my experiments with carbon calculators, I've been noticing more and more just how variable they can be. The results they spit out fluctuate wildly but as they all ask slightly different questions, that's not surprising. What surprises me are the differences between what they claim the CO2 emissions of your average Briton are, and if your trying to figure out whether you're a relatively big emitter or a teeny tiny one, that can be something of a problem.

As reported in yesterday's news, London's congestion charge is being modified again to improve the capital's green credentials. From October, vehicles emitting the highest amounts of CO2 will have to pay £25 a day which gets a big thumbs-up, while the most efficient cars will get into central London free of charge.

Some commentators have pointed out that this effectively changes the purpose of the charge from reducing congestion to reducing pollution, and that's no bad thing. According to the World Resources Institute, road transport spews out around 10 per cent of global emissions (pdf), so providing incentives to move to more efficient models is going to do a lot to cut those exhaust fumes.

Emissions from municipal services such as road maintenance are included as part of indirect emissions © Greenpeace/Steve Morgan

In my last post about carbon calculators, the tricky question of indirect emissions came up. I'm putting my own life through various calculators and seeing how they compare, but in trying to log my daily activities that consume energy and resources there are a number of unknowables.

In the past, I've been a bit sniffy about carbon calculators and have tended to dismiss them, although if I'm honest it's been on principle rather than first-hand experience. From what I've seen, they oversimplify an incredibly complex issue and, as a colleague pointed out, shift the weight of responsibility onto individuals when it should be an energy-efficient government that leads the way.

But then I came across mobGAS, a calculator produced by the European Commission's Joint Research Centre which sits on your mobile phone and allows you to enter daily updates about your energy consumption. Hurray, a new application for me to fiddle with in a borderline obsessive-compulsive manner, and an excuse for a broader look at carbon calculators in general.