Here’s a fun web app from the Bon Appetit Management Company:
Basically, you calculate the carbon impact for a range of meal options by dragging food icons into a skillet. On a thermometer with the usual green, yellow, and red indicators, the app then shows you the number of “carbon points” for your selection. (Warning: you know perfectly well where that cheeseburger-and-fries is going to end up.)
The site also offers information about the research underlying the app and advice about reducing climate change through mindful munching.