I used to think the truth would set us free. Like many who care about the environment, I spent years thinking that information would lead to change. If only people realize the mess our planet is in, I thought, things will change. So I wrote reports, gave speeches, even testified before Congress.

Some things changed. Sadly, the big picture didn’t.

For a long time I couldn’t understand why. Now I’ve realized we don’t need more data, white papers or documentaries to tell us we’re in trouble. Every day, the news is full of extreme weather disasters, toxic chemical scares and the cruel consequences of economic inequality. At this point, most people know.

And the good news is that most people care. Most of us want a safe and healthy environment. Most of us are horrified by the idea of babies born with harmful chemicals in their blood. Most of us would rather see investments in clean energy than billion-dollar subsidies for fossil fuel fatcats. Most of us would prefer to live in a just society.

So, if people know, and if people care, why aren’t we generating the level of change needed to turn things around? My new movie, The Story of Change, argues it’s partly because we’ve gotten stuck in our consumer mode.

I’ve come to see that we have two parts to ourselves; it’s almost like two muscles—a consumer muscle and a citizen muscle. Our consumer muscle, which is fed and exercised constantly, has grown strong: So strong that “consumer” has become our primary identity, our reason for being. We’re told so often that we’re a nation of consumers that we don’t blink when the media use “consumer” and “person” interchangeably.

Meanwhile, our citizen muscle has gotten flabby. There’s no marketing campaign reminding us to engage as citizens. On the contrary, we’re bombarded with lists of simple and easy things we can buy or do to save the planet, without going out of our way or breaking a sweat.

No wonder that, faced with daunting problems and discouraged by the intransigence of the status quo, we instinctively flex our power in the only way we know how—our consumer muscle. Plastic garbage choking the oceans? Carry your own shopping bag. Formaldehyde in baby shampoo? Buy the brand with the green seal. Global warming threatening life as we know it? Change our lightbulbs. (As Michael Maniates, a professor of political and environmental science at Allegheny College, says: “Never has so little been asked of so many.”)

Now, all of those are good things to do. When we shop, it’s good to choose products without toxic chemicals and unnecessary packaging, made by locally based companies that treat their workers well. On the other hand, shunning products that are unhealthy for workers, communities and the planet sends a message to companies that are still stuck in the dinosaur economy. Sometimes not buying—making do with what we have or sharing with a friend – is the best option of all.

But our real power is not in choosing from items on a limited menu; it is in determining what gets on that menu. The way to ensure that toxic, climate-disrupting choices are replaced with safe and healthy alternatives—for everyone, not just those who can afford them—is by engaging as citizens: working together for bigger, bolder change than we could ever accomplish on an individual consumer level.

Look back at successful movements—civil rights, anti-apartheid, the early environmental victories—and you’ll see that three things are needed to make change at the scale we need today.

First, we need a Big Idea of how things could be better—a morally compelling, ecologically sustainable and socially just idea that will not just make things a little better for a few, but a lot better for everyone. Millions around the world already have that idea: an economy based on the needs of needs of people and the planet, not corporate profit.

Second, we need a commitment to work together. In history’s most transformative social movements, people didn’t say, “I will perfect my individual daily choices,” but “We will work together until the problem is solved.” Today, it’s easier than ever to work together, online and off.

Finally, we need all of us who share that Big Idea to get active. We need to move from a place of shared concern, frustration and fear to a place of engaged citizen action. That’s how we build the power to make real change.

We have to aim high, work together and act boldly. It’s not simple, and it certainly won’t be easy. But history is on our side. Let’s get to work to make the kind of change we know is possible.