Carbon-footprint calculators and their lessons

CHRIS JONES of the University of California, Berkeley, was on a river in the Amazon rainforest when he put the finishing touches on the world’s first online household carbon calculator. That was in 2005. He hoped that, if he could show people how much greenhouse gas was associated with daily activities—driving the car, heating the house—they might change their behaviour and contribute in some small measure to saving the Amazon. Seventeen years and a proliferation of rival calculators later, trackers are providing a wealth of often-neglected information about the carbon emissions of everyday life. They provide local and micro data which usefully supplement the global findings of the Intergovernmental Panel on Climate Change.