How ‘green’ are you? Now there’s a very simple (and therefore surely inaccurate, but probably not too misleading) online questionaire you can take (from National Geographic), to make you feel smug or worried about your carbon footprint (most of us in the London office wound up with a smug, above-average Greendex score, though that’s probably because none of us own a car…).

Working out the environmental pros and cons of various activities is notoriously difficult and at times counterintuitive. A report in Nature once concluded, for example, that it’s better to use a styrofoam cup than a mug for your daily coffee, until you had used the same mug over a thousand times – that’s thanks to the high-energy-use manufacture of ceramic, and the hot water and soap needed to wash your mug; in contrast styrofoam is easy to make, and causes no problems in landfill other than taking up space (Nature abstract, full text not online; .html">New Scientist story). At least with carbon emissions there’s no need to quantify some amorphous ‘bad’ thing like ‘taking up space in landfill’ – carbon emissions are carbon emissions (well, the carbon could be in methane or carbon dioxide, with differing climate effects, but lets not be too picky). But it’s still hard to assess with simple questions like “Do you own a car” exactly what this means for your emissions.

Nonetheless, I’m all for raising awareness of carbon footprints – so long as it doesn’t make people who get a ‘good’ score think they don’t need to strive for improvement.

Here are some more, similar surveys:

Carbon offset survey, run by Environmental Economics MSc students at Imperial College, London.

Test your knowledge on environmental questions, with a quiz from Yale University, Forbes, and the BBC.

Tell us of your favourites…