SAN FRANCISCO — For years, presidents and prime ministers have been the public face of the fight against climate change, gathering at United Nations summit meetings and pressuring each other to reduce emissions.
The results have often been lackluster.
A climate conference in California this week tried something different. The meeting, organized by the state’s governor, Jerry Brown, had far fewer national leaders present. Instead, an array of governors, mayors and business executives from around the globe met to promote their successes in cutting greenhouse gas emissions locally and to encourage one another to do more.
A key premise of the conference was that if a handful of leading-edge states, cities and businesses can demonstrate that it’s feasible — and even lucrative — to go green in their own backyards, they might inspire others to follow suit. That, in turn, could make it easier for national leaders to act more forcefully.
“If a researcher does an experiment, and you find out they’ve got a medicine that works, it spreads,” Governor Brown said.
There was no shortage of announcements at the meeting. Cities like Tokyo, Rotterdam and West Hollywood signed joint pledges to only buy zero-emissions buses after 2025. Companies like Walmart and Unilever rolled out new programs to limit deforestation in their huge supply chains. Dozens of philanthropic groups committed $4 billion over the next five years to fight climate change.
But it will take time to tell whether these local actions can scale up quickly enough to make a significant dent in global emissions. And scientists are warning that time is short if we want to avoid the worst effects of climate change.
On Thursday, a group of researchers released a road map for what it would take to keep global warming below 2 degrees Celsius, the internationally agreed-upon goal. It entailed a rapid transformation of the world’s energy system (measures such as banning the sales of gasoline vehicles in many cities within a decade) that went far beyond many of the proposals made in California.
The sheer scale of that challenge hasn’t fully sunk in with many policymakers, said Johan Rockström, a sustainability scientist and co-author of the report. “We need to be thinking about exponential changes.”
Getting the U.S. back on board
The American politicians at the conference, who typically came from liberal cities and blue states like New York and Washington, had a more immediate concern: Trying to persuade the rest of the world that the United States hasn’t completely abandoned the fight, despite the fact that President Trump has vowed to withdraw from the Paris Agreement on climate change.
Governor Brown met with Xie Zhenhua, China’s chief climate negotiator, and announced plans for California and China to work together on zero-emissions vehicles and fuel-cell research. Later in the week, several blue-state governors met behind closed doors with the environment ministers of Canada and Mexico to forge new partnerships on issues like electric vehicles and curbing emissions of methane, a potent greenhouse gas.
It was an unusual situation: A handful of American governors were effectively taking the lead on international climate diplomacy at a time when the president has disengaged on the issue. But some foreign officials were happy to reciprocate.
“It is important to show the world that we’re still working with U.S. states,” said Catherine McKenna, Canada’s minister of environment and climate change, in an interview. “There really are practical things we can do together.”
There were even a few substantive policy announcements. California, New York, Maryland and Connecticut said they would craft new regulations to curtail hydrofluorocarbons, the highly potent greenhouse gasses used in air-conditioners and refrigerators. In 2016, nations agreed on a treaty to phase out these gases, but Mr. Trump has not submitted the pact for ratification or written federal regulations.
While businesses would prefer a single federal standard, even a few states acting together could create a significant market for cleaner alternatives to HFCs, said Caroline Davidson-Hood, general counsel for the Air-Conditioning, Heating, and Refrigeration Institute, an industry group.
Yet for all that, local leaders in the United States who have promised to uphold the Paris climate agreement still face an uphill battle.
Their coalition — which now consists of 16 states, Puerto Rico, hundreds of cities and nearly 2,000 businesses — has vowed to press ahead with climate action and ensure that the United States meets former President Barack Obama’s Paris pledge to cut greenhouse gas emissions 26 to 28 percent below 2005 levels by 2025.
A new report commissioned by the group found, however, that United States emissions are on track to fall only about 17 percent over that span.
Those states and cities would have to pursue ambitious new policies, like retrofitting hundreds of buildings to make them more energy efficient and plugging methane emissions from landfills, to get closer to the target. They would also have to persuade several other states beyond the blue coastal enclaves to join them, the report found.
“We can’t just leave this to the states that have been the first movers,” said Mary Nichols, who heads the California Air Resources Board. “We need others to join us as well.”
Looking ahead to the U.N. talks
While the California conference did see a flurry of announcements by states, cities and businesses from around the world, some of them seemed more aspirational than anything else, at least for now. It is unlikely that this meeting, by itself, will drastically alter the trajectory of the world’s emissions.
For example, mayors from dozens of the world’s largest cities promised to cut the amount of trash they send to landfills in half, build more carbon-neutral buildings and encourage walking and cycling in their cities over the next few decades. But how well these mayors follow through remains to be seen.
Despite questions like that, however, some analysts made a case that one big benefit of the conference could be to generate a broader sense of momentum around action on clean energy and global warming as United Nations climate negotiations are entering a particularly difficult phase.
In December, countries will meet in Poland to finalize a “rule book” for implementing the Paris Agreement — touching on contentious topics like how to track and verify emissions cuts. Over the next two years, many nations will then have to decide whether to strengthen their national pledges on climate action, which are currently far too weak to avoid drastic warming.
Yet preliminary negotiations around these issues fell into disarray at talks in Bangkok this month, as poorer countries accused wealthier nations, including the United States, of reneging on their promises for financial aid to fight climate change.
“The U.N. talks are still locked in this finger-pointing dynamic, where people act as if tackling climate change as a zero-sum game,” said Alden Meyer, the director of policy and strategy for the Union of Concerned Scientists, who had flown to San Francisco from the Bangkok talks.
“The atmosphere here in California has been different, there’s a real can-do spirit,” he said. “We’ll see if that mentality can permeate upward.”