Last Sunday, hundreds of thousands of people converged on New York City to demand action on climate change. With an estimated 400,000 in attendance, the People’s Climate March was by far the largest climate march in history. I was one of the people there, and I truly believe that the march as a whole, and I, really mattered.

I think I’m a fairly responsible citizen in terms of my fossil fuel use. I ride a bike on short commutes, I try to buy organic food and I shut off the lights when I leave a room. But even if I were to go further and reduce my individual carbon footprint to zero, it would still not make a large difference in the overall concentration of greenhouse gasses in the atmosphere. Individual lifestyle changes are not enough to effect a global movement toward the survival of our planet. The solution to climate change must be large-scale, and it must be coordinated.

Since the alarm bells were sounded on global climate change in the 1980s, politicians in the United States have been dragging their feet on taking meaningful steps toward creating climate policy that would lead to emissions reductions on the scale that is needed. The Kyoto Protocol is a case in point. The People’s Climate March was about changing the status quo of inaction at the highest level.

There was no bill in Congress that we were rallying around on Sunday. In fact, those of us at the march had no unifying demand for specific action whatsoever. We were there to demand that politicians take action.

For every individual who contacts a politician, their opinions are considered to represent a much larger number of constituents who just haven’t called. Traveling to New York City takes a lot more time, energy and passion than picking up the phone. If a call represents the views of 10,000 constituents, then imagine how many voters were represented by the presence of 400,000 people marching in New York City.

Most everyday climate change work happens at the state and local level, and this makes it difficult to see the size of the overall movement on a national and global scale. By unifying people from all over the nation and world in one main location — raising our voices in one unified call for action — we sent a very clear message to the people who have the power to directly change things: “We demand large-scale action on climate change, and we’re getting impatient.”