We have a problem. It's clear that global climate change is upon us, but what do we do about it?
Finding out which actions work best to reduce greenhouse gas emissions is a challenge.
There are plenty of suggestions: Switch to a fuel-efficient vehicle! Plant some trees! Fly less! Bring your own plastic bags to the grocery store!?
But there were so many options, I started to wonder. Which of these actions made the most difference? Which were the things I, individually, could actively do that have a measurable effect?