ClimateCounts, funded by a US organic yoghurt maker from New England, has produced climate-friendly ratings for major competing companies based on the company's track record on climate change. The ratings are on a scale from 0 to 100 and are based on 22 criteria which measure whether the company keeps track of the carbon it produces; the efforts made to reduce it; the company's take on global-warming legislation; and its disclosure to the public.

The idea behind the card is that consumers will factor the company's climate policy into a decision on whether or not to buy that company's product, according to Adam Markham, executive director of Clean Air-Cool Planet . . . one of the groups that helped create the scorecard. It should add to the variety of factors such as price, quality and service that normally influence consumer decisions.

Six companies, including CBS and Amazon received zeros, and the highest score attained was the 77 awarded to Canon. Sixteen of the 56 companies received less than a 10. As the scorecard will be released annually, each company will have a chance to better its rating in the course of the year and new companies will continuously be added to the list.

"I think Diageo [the parent company of Guinness] would certainly be big enough to be covered in the future and there are plans to do companies in the British Isles, " Markham said. "We'd like this to cross the Atlantic and be seen as a useful tool for Irish consumers."

The scorecard is available for download at www. climatecounts. org and, in answer to the above questions, the climate-conscious consumer should choose a Big Mac over a Whopper, a Coke over a Pepsi and Windows over Google. It may be a while before the Guinness v Bulmers debate is adjudicated.