This weekend in New York City, I’m going to be part of something truly unusual. I’ll be one of more than 2,000 people who will form a moving human sculpture of our world in a race against time: a massive, living planet earth and hourglass. Called the Human Countdown, this event will be broadcast by media outlets around the world, and will send an urgent message to leaders that time is running out to take action on climate change.

Why is now such a crucial time? Because, two days after this event, world leaders are gathering in New York for the UN Climate Summit—the first in a series of key moments when presidents and prime ministers will make major decisions about the future of our planet. Leaders, including President Obama, are meeting in New York and Pittsburgh in September and in Copenhagen in December, where they will decide whether or not to stop the clock on climate change.  

I’ll be there, blogging about the event for Oxfam. And if you’re concerned about climate change—especially the way it’s already affecting poor people here and abroad—I hope you’ll be there too. Having just come back from Ethiopia, where I saw communities facing increasingly severe drought, I feel a new sense of urgency to get away from my desk and actually do something about it.

The Human Countdown will be held at the Wollman Rink in Central Park on Sunday, September 20, and will feature national and international speakers, celebrities, and great music. Sign up to be part of it on our website—hope to see you there.