Those of us resolving to lead a lower-carbon life in 2010 could do worse than acquire a copy of Prashant Vaze's new book, The Economical Environmentalist, in which the author picks over the fine details of his life. He works out how much CO2 he could save by driving more slowly, installing loft insulation or becoming a vegetarian. The result will be a little dense for some, but it is delightfully geeky and has the virtue of being right more often than not.

This virtue is underrated. Environmentalists have been slow to realise that the fashionable eco-lifestyle is riddled with contradictions. The one that particularly exasperates me is the “food miles” obsession, whereby we eschew tomatoes from Spain and roses flown in from Kenya, in favour of local products grown in a heated greenhouse with a far greater carbon footprint.

Other less-than-obvious truths are: that pork and chicken have substantially lower carbon footprints than beef and lamb (yes, even organic beef and lamb); that milk and cheese also have a substantial footprint; that dishwashers are typically more efficient than washing dishes by hand; and that eco-friendly washing powders may be distinctly eco-unfriendly because they tend to tempt people to use hotter washes.