“RIGHT now, your individual behaviour does matter,” says Chris Jones. “Anyone can go carbon-neutral today. Better yet, you’ll probably end up with more money in your pocket when you’re done.” Jones’s group, the CoolClimate Network at the University of California, Berkeley, provides an online carbon footprint calculator. It estimates greenhouse gas emissions from transportation, housing, food, goods and services for any household in the US. Other groups provide similar calculators for many other countries. Despite individual and local differences, some broad generalities emerge. “Globally, the three main contributors to greenhouse gas footprints are cars, coal and cows,” says Jones. And those three things are where individual choices can make the biggest difference.