Since the monumental anti-climax of the Copenhagen conference in December, it has been very hard to find interesting and relevant environmental journalism. The media disenchantment is palpable. As a refreshing change, this weekend I discovered the BBC’s Ethical Man blog, written by Justin Rowlatt. Rowlatt’s approach to ethical living is rooted in science and in his latest post he sums up his attempts to calculate the most energy-efficient mode of travel, with a few controversial conclusions:

Cars are greener than public transport

Except, they aren’t. Well, they can be if they’re full and the bus/train isn’t. Rowlatt claims that the average UK bus only holds nine passengers (rising to 13 in London), so a four-seater car would be more eco-friendly, on a person per person basis. This argument is effective in highlighting the surprising state of affairs at the moment, but the only logical conclusion to be drawn is that more of us should take public transport. The more people use it, the more efficient it becomes.

Walking can be more polluting than driving

This may seem absurd, but there is a twisted logic at work here. Walking is energy-intensive and as a result of exercise we have to eat more food to refuel our bodies. With the aid of some rather rough science, Rowlatt concludes that the average human walking at 3mph has the carbon efficiency equivalent to 42 mpg (miles per gallon), and some hybrid cars are more efficient than this. Furthermore on an all-beef diet, this drops to 10mpg, making you the human equivalent of a Chevrolet Corvette. Whether you let his calculations stand or not, the fact remains that the vast majority of road cars are less efficient than 42mpg, by quite some way, so walking is almost always the more eco-friendly option.

Hitchhiking is the most carbon-efficient form of transport

Now this seems to be written with a hint of tongue in cheek, and rightly so. Rowlatt postulates that in a hitchhiking scenario, the driver was going to make his trip anyway, so by picking up a stranger he is nearly doubling his efficiency. Rowlatt concedes that hitchhiking is highly dangerous, although he does have a pretty amusing anecdote of hitchhiking to Glastonbury festival to commend this mode of transport. Having undertaken a similar journey myself, I can add another criticism – hitchhiking is incredibly slow! Perhaps even slower than walking. In my experience, you can be waiting hours to be picked up at any one location, and compared to that, the much maligned public transport system suddenly seems quite alluring…