I have been struggling to stay hopeful lately. The ways in which we are drawing down the ability of our planet to sustain and enrich our lives often seem too numerous to cope with and the appetite for change often seems too weak. Climate change is starting to bite. Hard.

In this context, it was incredibly inspiring to see hundreds of thousands of people take to the streets around the world and demand action on climate change. We know what we need to do. It's time to get to work.