This month, I have been revisiting the declaration that Sissel Waage and I made in our book: “Yes, we can” (and no, we don’t mind that a certain presidential candidate has also adopted the phrase!) Last year, this was our confident answer to the question: “Can we really win this fight against global warming?,” and our certainty was based on our faith in the power of individuals to bear witness to injustice, build coalitions, take their elected officials to task, and transform societies — the very power that shattered Jim Crow, ended apartheid, and ushered in women’s rights.

I admit, though, that I have recently had my doubts. Earlier this year, James Hansen and colleagues wrote that the world must reduce atmospheric concentrations of CO2 from about 390 parts per million to below 350 as soon as possible. If Hansen is right (and no climate scientist has had a better track record in the last 30 years), this is humanity’s most daunting task, ever.

So, can we really do this? The truth is that no one knows, but we must try. This, it seems to me, is the essence of Al Gore’s magnificent challenge last month to eliminate all carbon-based sources of electricity in ten years. We must try, as impossible as this goal may seem.

There is good news: Earlier this month, I was lucky enough to attend a gathering of like-minded folks in Salzburg, Austria for a four-day session titled “Combating Climate Change at Local and Regional Levels: Sustainable Strategies, Renewable Energy.” The array of locally-based solutions was breathtaking: the rapid growth of biomass in Northern Austria (see Dave Robert’s account in The Grist), the transformation of Freiburg, Germany into a sustainable city, and the building of a clean-energy coalition in the Midwest.

These and other recent examples (see this stunning compendium of Global Warming Solutions that Work from Rob Sargent and his colleagues) illustrate some simple truths about building local and regional solutions: you need strong leadership, a diverse enough coalition, and a emphasis on economic development alongside the call for sustainability and climate justice. Throw in a dash of luck, and determined coalitions really can make a rapid transformation to clean-energy.

And yet … it’s simply not enough. Add up all of the locally and regionally based solutions of the last decade, and we still are only making a modest dent on our collective greenhouse gas impact. Ultimately, we need the strongest possible national and global policies. In the words of Thomas Friedman, we need to change the rules and scale up.

In fact, I believe that this is the true value of all of the extraordinary local and regional initiatives that I learned about in Salzburg: as learning laboratories for global scaling up. By pursuing locally-based solutions to this global challenge, leaders are learning what technologies are most cost-effective, how to finance these technologies with private and public support, and how to build new coalitions. We will need these and other lessons, big time, as we build global institutions for scaling up. (On this essential topic, read the compelling “Climate Choreography” from Lew Milford and his colleagues.)

How to accelerate this process of changing the rules, scaling up, and building new institutions? That’s where the global climate movement comes in. With the strongest possible national legislation from the next American president and a renewed commitment to collaboration from the world’s leaders, we can begin to move towards a carbon-free future. So make a video, join 1Sky, We Can Solve It or other groups and become active in your community. And don’t forget to begin at home: assess your own impact and take steps to conserve what you can, and offset the rest. May the drive to 350 begin. The world can’t wait.

-Jon Isham, co-founder of Brighter Planet

In addition to founding Brighter Planet, Jon is the Luce Professor of Environmental Economics at Middlebury College and co-editor of the book “Ignition: What You Can Do to Fight Global Warming and Spark a Movement“.