For most of the last year the environmental news has been bad: first, the Copenhagen summit on climate change failed to produce any agreement, and then the U.S. Congress decided not even to vote on a new energy law. And then we came through the toughest summer the northern hemisphere has ever seen, a taste of what global warming feels like in its early stages: 19 nations set new temperature records, Russia caught on fire, and Pakistan all but drowned.

So the question is what to do.

And our answer is: get to work.

A year ago, 350.org organized a giant political rally, what CNN called the “most widespread day of political action in the planet’s history,” with 5,200 demonstrations in 181 countries. This October we’re doing something different, and even bigger. We’re calling it a Global Work Party, and on 10-10-10, in more than 7,000 places in almost every nation on earth, people will be putting up solar panels or digging community gardens. In the Philippines, thousands of people will be replanting mangroves along the ocean’s edge; in Auckland, New Zealand, bike mechanics will fan out across the city to fix every cycle they can find; in Mexico, Boy Scouts will crisscross the city installing energy-efficient light bulbs.

The basic message: if our leaders won’t lead, we’ll have to show the way. For the moment, places like Canada are one of the top 10 global warming polluters in the world. But while the government avoids investment in renewable energy, they continue to spend over $1.5 billion per year subsidizing the dirtiest oil in the world. That doesn’t mean we can’t make the change ourselves, one community at a time.

Of course, we can’t solve climate change one bike path at a time. The weather in the past few months shows just how dangerous global warming has already become. So at the end of each work party, we’re asking participants to lay down their hammer or shovel and pick up their cell phone. We need them to call their president or prime minister or Politburo and offer a simple message: “We expect you to get to work too.”

One day of hard work won’t make us as powerful as the fossil fuel companies. But it’s a key step in continuing to build the movement to safeguard the climate. And it will demonstrate what a broad movement this is: most of the people who will be hard at work on Sunday Oct. 10 aren’t traditional “environmentalists”– they’re people who care about peasant farming, about public health, about fighting poverty and making peace. That is, they’re people who care about all the things that a wrecked climate will make impossible.

They know a couple of things. One, that 350 is the most important number in the world — as NASA scientists put it two years ago, if carbon in the atmosphere exceeds 350 parts per million we can’t have a planet “similar to the one on which civilization developed and to which life on earth is adapted.” And the bad news is we’re already too high — the air holds 390 parts per million CO2. That’s why the Arctic is melting and the sea rising.

The other thing those people know: We’re never going to have as much money as the coal and oil and gas industry, so we need to use our bodies and passion and creativity instead. On 10-10-10 we’ll be at work in 7,000 communities around the planet — but we’ll be working together.

Bill McKibben is founder of 350.org and a scholar in residence at Middlebury College in Vermont.