Back in the 1990s, Gao received a letter from an old friend who was living in the United States. The letter included a photo clipped from a newspaper, showing President Bill Clinton as he announced a plan to outfit 1 million homes with solar power. “It was like a lightbulb,” Gao recalled, as we were sitting in his office in Changzhou, about 100 miles northwest of Shanghai. Clinton’s initiative caused Gao — a chemist by training — to think that he should start a company to meet the coming demand for solar equipment. That company, Trina Solar, has since made Gao a billionaire. For the inspiration, Gao is grateful to the United States. But he is also befuddled by the American approach to climate change. “There is really conflicting policy,” he said. He rattled off the names of recent presidents — Clinton, Bush, Obama, Trump — and moved his hand back and forth, to describe the sharp policy changes from one to the next. Those changes, he added, had hurt the solar industry and other clean-energy efforts: If the United States took a more consistent approach, the global struggle to slow climate change would be easier. Many Americans have come to believe a different story — namely, that US climate policy hardly matters compared with the actions of China, India and other countries that account for a growing share of emissions. As some congressional Republicans have been asking this week, why should the United States act to slow climate change unless other countries do so first? But that view is not consistent with history, either the recent history of climate diplomacy or the broader history of American influence. “There aren’t many other areas of policy where we say, ‘Why don’t we let everyone else lead, and we’ll follow?’” as Nathaniel Keohane of the Environmental Defence Fund says. The United States, for all its problems, remains the world’s most powerful country. When it wants to influence the policies of other countries, it can often do so, especially when those countries see it as being in their own interests to change. Climate is just such an issue. Leaders of many other countries understand that climate change and extreme weather can cause problems for them. The United States can’t simply dictate terms. Both China and India, for example, will remain more reliant on coal than Biden administration officials wish. But the United States can often have an effect. Relative to many other issues, in fact, climate diplomacy is sometimes easier: President Xi Jinping has largely rejected US entreaties on Hong Kong, Xinjiang and the South China Sea, but he has been willing to deal on climate change. President Barack Obama and Xi came to multiple agreements that involved both countries moving to reduce emissions. They started small, with the relatively narrow topic of refrigerants, and expanded from there. As my colleague Brad Plumer says, “There’s a reasonable argument the Obama administration’s and China’s joint agreement on climate change in 2014 helped set the table for the Paris climate agreement.” Crucial to these efforts was a United States willing to act at home: It’s much easier to agree to take economic risks when your main global competitor is doing the same. And the United States still leads the world in per-person emissions, about 75% above China, according to recent numbers. The Trump administration slowed global efforts on climate change by dismissing it as a threat and allowing more pollution at home. A Chinese official last week mocked the United States for “the lost four years.” The Biden administration is now trying to reverse course, with an emissions-reduction goal that’s larger than many advocates expected. The cynical view — that the United States can only follow, not lead, on climate policy — has it backward. As Gao told me, one of the biggest obstacles to progress on climate change has been the lack of consistent American leadership. © 2021 New York Times News Service