I'm in Paris right now, honored (and lucky, given how much I love croissants!) to be at the United Nation’s climate change summit, along with my longtime friend and colleague Anna Aurilio, the director of our DC office. Over the next few days, I’ll be sharing my perspective from this historic event, officially called the 21st Conference of Parties, or “COP21.”

If you’re reading this, you probably know how important this conference is for the future of our planet. We used to think of global warming as a problem that would happen someday, somewhere. But as we begin the last month of what is quite likely to be the hottest year ever (following 2014, which also set a record), it’s clear that someday is now. And with extreme floods, storms, drought and wildfire causing devastation from continent to continent, for too many people right now all across the world, somewhere is here.

So COP21’s mission couldn’t be more profound or ambitious: reach a bold international agreement toward limiting warming to less than 2 degrees Celsius over pre-industrial levels, thereby avoiding some of the most catastrophic impacts of climate change. It’s an enormously complicated task for our planet of more than 7 billion people. But it boils down to a rather simple solution: drastically curb pollution, and transition to 100 percent clean energy.

Will an accord achieved over the next handful of days get us there? Not all the way, not in and of itself. But since 150 nations -- making up more than 90 percent of the world’s greenhouse gas emissions --- made climate commitments before the conference even began, I'm optimistic world leaders will agree to set our planet on the right path.

I'm a glass half-empty kind of person, so my optimism says a lot! And it was stoked further this morning at a gathering at Paris’s gorgeous city hall (Hotel de Ville). The Cities for Climate event -- sponsored by the City of Paris, Michael Bloomberg (special UN envoy for cities and climate change) and Bloomberg Philanthropies, among others -- showcased the work cities are already doing to act on climate, and featured some inspiring speeches from the special envoy to China, Elon Musk, and French president Francois Hollande.

Most notable among the speakers were the mayors from around the world, those who often absorb the biggest brunt of global warming’s impacts.

At Environment America we’re proud to have played a role in organizing mayors and other local elected officials in the U.S. for climate action – from producing a video with the mayors from Los Angles, Philadelphia, and Houston; to recruiting more than 60 mayors onto a statement calling for bold action in Paris; to mobilizing more than 600 local elected officials in favor on the strongest action the U.S. has ever taken on global warming.

As one mayor put it, local elected officials are “closer to the problems, closer to the people, and critical to solving the climate crisis.”

So true. As I said during a “Google Hangout” interview in conjunction with the Cities for Climate event, the more organizations like ours reach and mobilize mayors and others already feeling the impacts of global warming, the more likely we are to come together for bold climate action, in Paris and beyond.