Last week I ended up in jail for a little while, because I’d sat down in a Congress member’s office to protest the deadly confluence of climate and immigration policy. You can read about my day in the New Yorker1, but my point in sharing it with you is not to say that I acted nobly or that it was a big deal.

Instead, my point is simply that sometimes you have to act even if you’re not entirely sure what the effect will be. We’re coming up on the next great moment in the climate movement, the global all-ages climate strike on Sept. 20. Years of sustained resistance from Standing Rock to the school strikes and beyond, particularly from youth of color, have led us to this moment. So let’s make the most of it.

We’re now just one month away from the Global Climate Strike. Join your community members, coworkers, and children in the streets at an event near you, or host one yourself.

Whatever you do that day — whether you walk out of work or school, close down your business, or join a protest, it will help build the groundswell that is now clearly rising.

When you strike, you’ll be striking for justice above all — it’s one thing you can do on behalf of those who are incarcerated at the border, or who are living so close to the margin that taking a day off is not possible. If you have some flexibility in your life, it’s time to put it to work. If you don’t, sign up anyway, we’ll find other ways for you to participate and show your support.

The UN’s best guess is that unchecked climate change could produce a billion climate refugees this century. Think about that for a moment — a billion people whose lives would be utterly, permanently, devastatingly upended. Then think about whether you can take a day to do something real about it, even without knowing exactly what change it will produce.

It’s time for all of us who can to take action for a more just and sustainable world. Join the Global Climate Strike starting on September 20th and fight with me for the future we all deserve.

Together we build movements, and when those movements get big enough they change history. You change history. Thank you for being a big part of it

Let’s make change,

Bill McKibben

1 – Protesting Immigration Policy, and Why I Decided to Get ArrestedThe New Yorker