09/18/2014 04:29 pm ET Updated Nov 18, 2014

Why the World Must March for the Climate

One of the more remarkable days in my political career came in the fall of 2009. The climate change activists at were putting together their first big global day of action, and they asked us in the Maldives for help. I was the newly elected president, and I had plenty on my plate -- but in the end there's no bigger issue than climate change for the Maldives, since the rising sea calls our very existence into question. The highest point in our archipelago is just a few meters above the Indian Ocean. Though these islands have been settled for 5,000 years, their future looks bleak.

And so I did something unusual. I persuaded the other members of my cabinet to either learn to scuba dive, or to dig out their own scuba gear. And we met -- masks and tanks on -- around a table set up a few meters beneath the surface of the sea, against the backdrop of some of the bleached coral that the warmer waters of our new ocean had killed.

At our underwater cabinet meeting we signed a proclamation (on plastic, not paper!) asking the UN to take serious action. And the resulting picture went all over the world.

It didn't, in the end, persuade other world leaders to take the steps we must take to slow down global warming. The huge climate conference at Copenhagen a few weeks later did not produce the scale of change that physics requires. But that picture did help alert people around the world to the problem of our warming, acidifying ocean.

Symbolic politics of this sort is very important, because before we can have policy we need political will. And political will comes when people are engaged, mobilized and fired up. I know this because I was able to help end a long-running autocracy in my nation because of the power of a people's movement. And I know that we need a movement if we're going to ever get real action on climate.

That's why it's so important to be a part of the upcoming People's Climate Mobilisation. A large march is planned in New York City on Sept. 21 and will be joined by other events worldwide taking place over the weekend. This is going to be the biggest gathering in the history of the climate change fight -- and the most diverse. People from labour, from faith groups, from the environmental justice community; people from all around the world, including those nations like mine that have done so little to cause the problem and yet stand to lose so much.

There will be at least 2000 events in more than 150 countries: people marching to submerged lighthouses on the New Guinea coast, people holding hands across the U.S.-Canadian border. Delhi will see a major demonstration, which is good since India will play such a pivotal role in the years to come. It will be a day unlike any other, when people around the planet actually think about the planet for once -- not their particular corner of it, but the whole thing, since that's the only way we'll ever solve this dilemma

It's not that marches by themselves will solve the problem. They won't. But they're one part of a necessary strategy. Since the fossil fuel industry has all the money in the world, and has effectively used it to block change, we need something money can't buy: numbers, spirit, creativity. All of those need to be on display during the People's Climate Mobilisation -- and they will be. I've seen the pictures already from the warehouses where people are building floats, and the endless array of beautiful posters. I know that around the world people will be sounding the climate alarm, making a noise so loud that even the most inert leaders will have to hear. It's the right image: it's time for the smoke alarm to go off, since the planet's on fire.

And if people turn out in a really massive display of force, it will make it so much easier for those of us continually meeting and conferring and negotiating. These tedious rounds of international talks clearly haven't gotten us very far -- there's been endless talk, but it's resulted in very little action. Since we can't afford another Copenhagen, something has to change. And let me tell you, speaking as a politician, that it's much easier to drive a good bargain when you have some power at your back -- and all of you are the power.

Be sure to join, make some noise and be a part of this historical moment -- you don't even need a scuba tank!

This post is part of a month-long series produced by The Huffington Post in conjunction with a variety of events being held in September recognizing the threats posed by climate change. Those events include the UN's Climate Summit 2014 (to be held Sept. 23, 2014, at UN headquarters in New York) and Climate Week NYC (Sept. 22-28, 2014, throughout New York City). To see all the posts in the series, read here.