Late last year, Chinese officials gathered to discuss the disastrous state of their country's air, soured by toxic chemicals and laden with greenhouse gases.
"China's emissions of all types of air pollutants and carbon dioxide are the largest in the world," lamented Wang Jinnan, chief engineer of the Chinese Academy for Environmental Planning.
For a decade now, China has been the global leader in carbon emissions, far eclipsing the United States as it erected forests of smokestacks to deliver exhaust heavenward on a march of economic growth powered in large measure by coal.
And yet the image Chinese Premier Li Keqiang sought to strike on Thursday was of a country prepared to offer a very different kind of leadership.
China "will stand by its responsibilities on climate change," standing alongside the European Union as a bulwark of responsibility in a world buffeted by a White House vacillating on the most pressing issues, Mr. Li said during a visit to Berlin.
It was less than five months ago that Chinese President Xi Jinping came to Switzerland with a very similar message. In a world plunging toward isolation, China would continue to champion globalization and global economic governance, he pledged.
"The history of mankind tells us that problems are not to be feared," he said, his words as applicable to beating down trade barriers as to fighting off climate change. "What should concern us is refusing to face up to problems and not knowing what to do about them."
To a troubled world, China has, more than any other time in recent history, offered hope. What U.S. President Donald Trump and Vice-President Mike Pence seek to tear down, Mr. Xi and Mr. Li will seek to protect. When a leadership gap emerges, China will step in.
Less than an hour after Mr. Trump said Thursday the United States will pull out of the Paris climate agreement, China's People's Daily tweeted a link to a Facebook article – using two social-media services censored in China, but designed to reach a global audience – saying the foreign ministry had "reassured the world" Beijing would remain steadfast on climate.
"The Chinese see an opening, a rhetorical opening, when it comes to the United States. It's all about perception," said Patrick Chovanec, a prominent commentator on China's economy who is chief strategist at Silvercrest Asset Management "And people are going to buy into that, to some degree. But then there's the reality of what the Chinese are actually willing and able to deliver."
In other words: Beijing has been handed the microphone and is using it to talk a good game. "They are acquiring face, they are showing themselves to be good citizens," says François Godement, director of the Asia and China program at the European Council on Foreign Relations.
Taking a stand on an issue such as climate change is "very important in shaping the position one has in other countries. So it does have soft power value," he said. And China's stance of responsible partnership has won it rewards, through new-found respect among powerhouse countries such as Germany, whose Chancellor Angela Merkel spoke Thursday about creating "global progress together."
But when it comes to China's stance on climate, Mr. Godement said, "it's purely face. It's talk."
Even if China keeps to its climate pledges, after all, it has committed only to stop growing carbon emissions by "around 2030." The United States, by contrast, had agreed to cut more than a quarter of its greenhouse gas output by 2025 under the Paris climate deal it said Thursday it will abandon.
Yet at the same time, China's outsized carbon footprint, like its protectionist policies, places it in a position to make change with global ramifications – and on climate, signs have been gathering that Mr. Li's assurances were more than empty words.
Take coal, whose consumption has fallen now in China for three consecutive years.
Or take greenhouse gas emissions, where China appears on course to far exceed its 2030 pledge. Last year, prominent British climate researcher Nicholas Stern co-authored a paper that parsed murky Chinese data and discovered a possibility "that 2014 was the peak" – and, at worst, emissions would crest in 2025.
China has tied future industrial policy to building up its lead in manufacturing solar and wind power technology, and creating a leadership position in the manufacture of electric cars. It has ordered coal-fired power plants to halt construction.
"At the end of the day, what matters is what happens in China's domestic energy sector," said Joanna Lewis, an expert on Chinese environment and energy policies at Georgetown University, where she leads the Georgetown U.S.-China Climate Research Dialogue. And, she said, "the signs there are really quite positive."
China will soon "be launching what will be the world's largest cap-and-trade system for carbon, and they have very aggressive domestic clean energy targets."
Still, she described China as a "reluctant leader" in forums such as the United Nations climate negotiations, positioning itself among developing countries who call for others to do the heaviest lifting.
"The position has always been, we're willing to take action, but it's up to the industrialized countries to lead and to provide financial and technology support."