Climate of Hope, released today, is both a timely and an aptly titled book. Co-authored by former New York City Mayor Michael Bloomberg and former Sierra Club Executive Director Carl Pope, the book’s subtitle -- How Cities, Businesses, and Citizens Can Save the Planet -- succinctly conveys the authors’ belief that urban areas, local and state government, business, and individual action (including exercising the right to vote) can turn the tide in the fight against climate change.

As the director of the Sierra Club’s Ready for 100 campaign, I am heartened that Bloomberg and Pope see the battle against global warming as one that can be effectively waged at the municipal level, irrespective of the current regressive political climate in Washington, D.C., and lack of leadership emanating from Inside the Beltway. Ready for 100 is asking mayors, pastors, principals, civic and community leaders, parents, and students in cities large and small to commit to solutions that will help us achieve 100% clean energy across the United States by 2050.

It’s easy to be despondent about climate change,” Bloomberg and Pope write in the preface to Climate of Hope. The issue received almost no attention during an 18-month presidential campaign that tested everyone’s patience. As a candidate, Donald Trump said he would ‘cancel’ the Paris Climate Agreement and roll back the Obama administration’s efforts to reduce greenhouse gases…. [And] the difficulty of preventing the earth’s temperature from rising sounds enormous enough to make people give up and just hope for the best.

“We see it differently. Through our work with cities, businesses, and communities, we believe that -- without much help from Washington -- we are now in a better position to stop climate change than ever before. And that in the years ahead, forces outside of Washington can and must deliver new levels of progress.”

Cities are getting the job done. Despite federal inaction and rollbacks of environmental protections, mayors and other municipal leaders are moving full speed ahead with some of the most ambitions goals and actions to reduce carbon emissions and move us ever-closer to the achievable goal of 100 percent renewable energy.

“In the United States and around the world, mayors tend to be more pragmatic and less ideological than national legislators, because they are more accountable to voters, and more visible,” Bloomberg contends. “The public can see what mayors do.”

Cities have many reasons -- including health, costs, economic opportunity, jobs, livability, to name a few -- to take action, and the fact that mayors are more accountable to their constituents is why you see greater ambition and more bipartisan leadership and cooperation at the municipal level.

“Cities are on the front lines of climate change,” says Atlanta mayor Kasim Reed. “We’re where the action is.” And Bloomberg makes the point that climate action, clean energy, and a clean environment are linked with economic growth.

“In order to attract the best and the brightest, cities must focus on creating the conditions that attract people,” he asserts. “This creates competition among cities -- which of them can offer the best schools, the safest streets, the biggest parks, the most extensive mass transit, and the cleanest air. If you live in a city and your kid goes to the hospital with an asthma attack and the city next door has cleaner air, you might call your mayor and say, ‘I’m not going to vote for you again unless you do something about it.’”

One of the biggest changes in urban governance in this century has been mayors’ recognition that promoting private investment requires protecting public health -- and protecting public health requires fighting climate change.

After the 2016 presidential election, there was a lot of speculation about whether the United States would fulfill the pledges it made in Paris. But, says Bloomberg, “[t]he Trump administration’s actions can’t and won’t prevent the Paris Agreement from reaching its goals. No matter what happens in Washington, no matter what regulations the Trump administration adopts or rescinds, no matter what laws Congress may pass, market forces local (and in some cases state) governments, and consumer demand for cleaner air will, together, allow the United States to meet and exceed the pledges that the Obama administration made in Paris. The reason is simple: cities, businesses, and citizens will continue reducing emission, because they have concluded … that doing so is in their own self-interest.”

Climate change, Bloomberg says, may be the first global problem whose solution will depend on how municipal services such as energy, water, and transportation are delivered to citizens. “Countries must do more to empower their cities to create cleaner infrastructure,” he says. “As the world becomes increasingly urbanized and cities become increasingly connected to one another, promoting the spread of best practices across national borders…. The faster nations embrace their cities as partners, the faster we can make progress on climate change.

The single most important development in the fight against climate change, contend Bloomberg and Pope, hasn’t been the Paris climate accord or even the advancement of solar, battery, or wind technology. “The most important has been that mayors, CEO’s, and investors increasingly look at climate change not as a political issue but as a financial and economic one -- and they recognize that there are gains to be made, and losses to be averted, by factoring climate change into the way they manage their cities, businesses, and funds. [We’re] optimistic this trend will continue, but not because Congress will become more enlightened. Congress does not lead; it follows.”

But wait. Does it make no difference what kinds of decisions emanate from the White House and Capitol Hill, and that cities and businesses alone can correct our climate follies?

No, says Pope. A number of key approaches clearly require national action. “Cleaning up methane from the oil and gas drilling on public lands, an Obama rule Trump would like to quash, can’t be replaced by state and local initiatives -- the federal government ultimately must become part of the solution. But just as during the Progressive era at the start of the 20th century, it was cities and states that forged the new policy instruments that eventually became the New Deal, rather than waiting for Washington. Mike Bloomberg and I believe that political leadership in the United States, and elsewhere, will come from below, not from national elites, which remain in thrall to the fossil lobby and other entrenched interests.”

But to break for a moment from Bloomberg’s & Pope’s central thesis -- that leadership and progress on climate will primarily come from the grassroots up, rather than from the top down, Climate of Hope is not only optimistic about our ability to curb global warming, it is also chock full of interesting -- and sometime scary -- facts and factoids.

For instance, who among you knew that after water, the most-traded commodity in the world is cement -- and that China used more cement between 2011 and 2013 than the United States used in the entire 20th century? Or that fully half of the world’s wetlands have been lost since 1900? Or that the two oldest modes of transporting goods -- ships and trains -- are by far the least polluting? Or that a quarter of airline carbon emissions occur during takeoff and landing, so to reduce our environmental footprint, we should fly direct? Or that buildings, not factories or cars, are the biggest source of carbon emissions? Or that cows are the largest source of methane, a potent greenhouse gas? Or that… well, you get the picture. Climate of Hope is determinedly accessible to the lay reader, and, given the gravity of the subject matter, fun to read. And it is brimming with optimism.

“We can stop global warming,” the co-authors write in the coda to the book. “Not by slowing down economies but by speeding them up. Not by depending on national governments but by empowering cities, businesses, and citizens. Not by scaring people about the future but by showing them the immediate benefits of taking action. If we accomplish this, we will be healthier and wealthier. We’ll live longer and better lives. We’ll have less poverty and political instability. And, while we’re at it, we’ll pass on to our children and their a brighter future.”

Those are the goals of the Ready for 100 campaign. Twenty-six cities have made the commitment to setting the goal of getting 100 percent of their energy from renewable sources within the next couple of decades -- among them San Diego, San Francisco, and Salt Lake City.

Want your city to join this list? Find out more at Ready for 100 and learn how you can make it happen. And as you ready yourself to talk with your neighbors and city officials and help build a local movement around why your city should take the plunge, enjoy an accessible, edifying, persuasive, and frequently fun read that will bolster your optimism and hopefulness in Climate of Hope: How Cities, Businesses, and Citizens Can Save the Planet.