A new climate mobilization is emerging; its first mission? The isolation of Donald Trump. Sunday's New York Times headline about the G20 meeting in Hamburg was revealing, but inaccurate: World leaders Move Forward on Climate Change: Without the U.S.

Yes, 19 of the 20 major economic players in the global economy agreed that the Paris climate agreement was "irreversible," that every nation needed to play its appropriate part, and that the future laid out in Paris, a decarbonized global economy in this century, was inevitable. Even oil exporting nations like Saudi Arabia and Russia, whom President Trump has viewed as favorite diplomatic buddies, refused to stand with him on climate. Trump's unwillingness to concede anything on climate meant that the rest of the G20 could adopt the stronger version of each of their climate communiqués.

But what the Times headline writer missed was that the world was not advancing "without the U.S."—it was simply advancing without the current administration. The Trump administration no longer represents American in the way that we have understood the presidency for decades.

The broader signs of the isolation of the Trump administration have been evident for months. But look at climate, and look at last week only.

Monday, the U.S. Conference of Mayors, representing 250 of America's largest cities, unanimously endorsed the goal of converting their electricity supply 100 percent to renewables like wind and solar. What was the Trump administration response? According to the Houston Chronicle, Energy Sec. Rick Perry was preparing to "order Americans to pay more for electricity to keep his boss's promises to coal miners, nuclear power plants and electric companies ..." by requiring them to buy coal or nuclear power even if it cost more than clean renewables!

Then, as Trump boarded Air Force One to fly to Poland and ask, plaintively, if "the West has the will to survive?" California Gov. Jerry Brown, representing the most dynamic and rapidly growing economy in any industrial nation, proclaimed his survival plan. Brown announced that in September 2018 he would host a global climate summit in San Francisco, warning that the president "doesn't speak for the rest of America" in pulling out of the Paris agreement on climate change ... it's up to you and it's up to me and tens of millions of other people to ... join together to combat the existential threat of climate change. That is why we're having the Climate Action Summit."

Even the Organization of Petroleum Exporting Countries broke with Trump and reaffirmed that they, too, supported the Paris agreement.

Talk about isolation.

A week later Brown joined with Mike Bloomberg, the former mayor of New York, to proclaim "America's Pledge," a groundbreaking mechanism for enabling the U.S., as a society, to participate in the global effort to curb climate change even while its normal representative, the Executive Branch of the federal government, struggles to hold back the tide.

America's Pledge is the latest expression of the new "bottom-up" diplomacy of climate, whose boldest achievement is, of course, the Paris agreement itself. From Kyoto through Copenhagen, the global community tried—and failed—to solve climate by arm-wrestling national governments into sharing sacrifice and imposing it on their citizens, like a tax bill.

They wouldn't pay it.

But in the aftermath of Copenhagen climate leaders like then UNFCCC Executive Christina Figueres, and U.S. climate negotiator Todd Stern, realized that, as Figueres put it, "the big boom was over." Climate was not going to be solved by a top-down agreement to share pain—it had to be healed by a bottom-up effort to seize the emerging opportunities that can make climate progress a short term, local win, as well as a long term, global necessity.

The Paris agreement reflected that. Nations didn't get handed a tax bill. They came forward with their own preferred actions—things their governments thought would be good for their own populations, like restoring forests in Kenya, or cleaning up power plants in the U.S. Some focused-on deforestation, some on renewable electricity, others on low carbon transportation fuels.

The Obama administration's Paris offer—a "Nationally Determined Contribution," consisted of things most Americans wanted to do anyway—replace outmoded, expensive and dirty coal power with cheaper, cleaner renewables; stop wasting valuable natural gas by letting it leak or be flared; provide motorists with cars and trucks and waste less fuel and go further on a dollar's worth of gasoline; modernize our building stock to reduce utility bills and increase comfort; and replace climate destructive HFC refrigerants with modern, American developed safe alternatives.

So in walking from Paris, Trump is compelled to threaten that his administration will block Americans from doing things that make them more prosperous, competitive, safer or healthier. Why does Energy Sec. Perry have to threaten states to get them to buy more coal power? Because it costs more than wind or solar.

Some, perhaps many, actions will, of course, require federal action—regulating oil and gas pollution on federal land for example. Others, like better building codes to reduce wasteful household energy bills, are primarily matters for cities. Innovating new technologies to replace HFC refrigerants are mostly going to emerge from the private sector. And the best way to figure out how to best leverage a price on carbon as a climate solution might be to let California and other states run a series of experiments and see whose method works best.

So why should America wait for Trump?

But there is a challenge with bottom-up solutions, a problem that "America's Pledge" is designed to solve. If dozens of states, hundreds of cities, thousands of universities and tens of thousands of businesses are each innovating and cutting emissions on their own, how do we know how we are doing? How can we learn from successes and failures? How can we stimulate the competitive instincts that make even more progress possible?

That's the gap "America's Pledge" plans to fill—to measure, report, compare and aggregate both the actions taken, and the opportunities yet to be taken, by an entire society. Because, at its heart, bottom-up climate progress requires mobilizing all of us, each one to do something that makes sense, and is good for us, but might not ever get to the top of our "to do list" if we didn't understand that we are part of something much larger, and much more important, than our individual steps.

That means, incidentally, that America's Pledge will have to be just as, or more rigorous, methodical and comprehensive than the "Nationally Determined Contributions" that made up the Paris agreement. That's a major challenge. But I think that what President Trump doesn't understand is that this is the kind of challenge Americans respond to—and I'm thrilled that Mayor Bloomberg and Gov. Brown have laid it on the table.