When President Donald Trump pulled the United States out of the Paris climate accord in 2017, pundits speculated about who would step in to fill the leadership void.

Many said it would be China, which had become the world’s biggest greenhouse gas polluter, but was rapidly deploying renewable energy and was eager to reduce the thick pollution choking its cities. Others predicted it would be states, cities, and businesses, which promised to step into the breach, with “We Are Still In” as their rallying cry.

Four years later, it is clear that while China ramped up clean technology and so-called “sub-national” actors maintained momentum toward emissions cuts, no leader emerged to steer the world anywhere near a path to meeting the Paris goal of holding warming to 1.5 degrees Celsius. 

If nations meet all the commitments they have made so far under the accord, they will reduce annual global greenhouse gas emissions by 3 gigatons by 2030, according to the latest United Nations report on the so-called “emissions gap.” But to meet the 1.5-degree goal, as scientists say is necessary to avert climate catastrophe, yearly greenhouse gas pollution must be cut by around 30 gigatons by 2030, the U.N. report said. That would be three times the current annual carbon pollution of China.

That leaves a monumental task for the 40 world leaders who will participate Thursday and Friday in the virtual climate summit organized by the White House.

President Joe Biden called the Earth Day conclave to mark the United States’ return to the Paris accord, and more broadly, to reestablish global leadership on climate action. Not only is the U.S. unveiling a new, more ambitious goal for curbing carbon emissions—a 50 to 52 percent cut by 2030—it is urging other nations to do the same. 

By scheduling the international meeting ahead of any roll-out of his anticipated domestic regulations on climate, Biden is sending a signal that what happens internationally is more important for the future of the planet than what happens in the United States. As Biden administration officials have said repeatedly, the United States currently accounts for only 15 percent of global emissions. 

“The world is way behind where we need to be,” said John Kerry, White House special envoy for climate change said Wednesday at a Washington Post Live event. “And this is going to take very dramatic efforts for all of us to make up the difference.”

China: Both Powerhouse and Laggard

Kerry claimed a minor diplomatic victory ahead of the summit on a whirlwind diplomatic tour in Asia. On his visit to Shanghai over the weekend, China agreed for the first time to acknowledge the existence of a “climate crisis,” in a joint U.S.-China communique. The statement included no specific goals, but said both nations would develop their respective strategies for meeting their long-term targets ahead of the climate talks scheduled for November in Glasgow.

Last September, in a video address to the U.N., President Xi Jinping announced that China would aim to become carbon neutral before 2060. Although that is 10 years later than the target date set by developed nations, including the United States, it marked the first long-term climate target set by Beijing and was widely seen as a milestone.

But China, which is now home to half the world’s coal power capacity, continues to make plans to expand its fossil-fueled fleet. In 2018, China lifted the construction ban on new coal plants it had set just two years earlier, giving rise to fear that Trump’s retreat from climate policy was spurring backsliding elsewhere in the world.

At the same time, China clearly seized global leadership in clean energy, as the leading producer of solar photovoltaic equipment and the world’s largest PV installation market. China has half of the world’s jobs in solar PV, some 2.2 million, nearly 10 times the U.S. solar industry’s employment base. 

China also was the world’s leading country for new wind energy installations in 2019, with all of its turbines supplied by Chinese manufacturers. China has 518,000 wind industry jobs, compared to 120,000 in the United States, according to the International Renewable Energy Association.

So China is coming into the summit as both a clean energy powerhouse and a laggard that is still spurring the build-out of dirty energy.

“Clearly, it’s a mixed bag,” said Alden Meyer, a senior associate at E3G, a European climate change think tank. “China has continued to ramp up its renewables, its investments in clean technologies and batteries. But at the same time they have continued to make investments totally inconsistent with their net-zero carbon dioxide pledge. So I think the real question—whether it’s at this summit or certainly before Glasgow—what more will China say about how it intends to live within the commitment that President Xi made.”

A Job Too Big for National Governments

At the summit, Biden also plans to put a focus on how cities, states and other sub-national actors can contribute to the drive to meet the Paris accord goals.

Among the scheduled speakers are New Orleans Mayor LaToya Cantrell, whose city adopted a clean electricity standard last year; Gov. Michelle Lujan Grisham of New Mexico, where updated building codes have ramped up the energy efficiency of new homes; and Claudia Sheinbaum, the mayor of Mexico City, Mexico, which is electrifying transit and taxi service with a goal of cutting transportation pollution by a third in three years.

In the United States, the states, cities, businesses, tribal groups, investors, faith communities and universities that have pledged deep cuts in carbon emissions represent nearly 70 percent of the nation’s gross domestic product, said Nathan Hultman, founder and director of the Center for Global Sustainability at the University of Maryland. In an analysis for the America’s Pledge project, Hultman and his colleagues concluded that their efforts could be critical in helping achieve a 50 percent U.S. reduction in greenhouse gas emissions by 2030.

“We’ve got to have a rapid global transformation over roughly the next decade, and what we’ve realized since Paris is that it’s really a job that’s even too big for just national governments to handle alone,” said Hultman, who served in President Barack Obama’s White House and helped develop the initial U.S. pledge under the accord.

Putting World Leaders on the Record

The White House has made clear that the climate summit—being held virtually across multiple time-zones—won’t include any bilateral meetings or dealmaking. Instead, the administration  hopes countries will use the platform to make more ambitious commitments to cut greenhouse gas emissions by 2030. And even if new goals aren’t forthcoming this week, it will be an opportunity to rally support for new pledges prior to November’s meetings in Glasgow.

Summit attendees will include both members of what once was called the “Major Economies Forum,” the 17 nations that account for nearly 80 percent of the world’s greenhouse gas pollution, and smaller nations that are most vulnerable to climate change, like Bangladesh and Vietnam. The White House has said all 40 national leaders who were invited have indicated they will attend.

If nothing else, the summit will put world leaders on the record as to why they believe the international agreement they signed onto—one with no targets or timetables—is adequate to address the climate crisis. Some of the countries that have already achieved their original commitments—including China, India and Russia—did so because they set only modest commitments. Other countries that made strong goals—like Australia, Brazil and Canada—are not on track to meet them.

“It’s something that we understood in Paris—the commitments that were made there were not adequate,” said Meyer. 

He said that’s why climate activists fought hard and successfully to build into the pact reassessment and ratcheting up of ambition every five years.

 “That’s the political moment we’re in now,” Meyer said. “And even if we get as much as we could hope for done in the run-up to Glasgow, there’s still going to be more work to be done. We need to have a sort of continuous improvement if we’re going to have any chance of meeting the Paris goals.”

This article has been updated to reflect the White House announcement of the United States’ emissions reduction target.