I’ve been rather concerned with this recently so was pleased to find that Google had made a handy app to calculate your carbon footprint. It syncs with your iGoogle home page, if you have one. I was delighted to work out that our household only generates a modest 1.37 tonnes of carbon, as we are too lazy (principled) to fly out of the country. Unfortunately, my husband flies regularly for work, although I am trying to get him to persuade his firm to offset their carbon miles. We have been holidaying in the UK for years, though, which helps, and our mileage on the car is very low.