There were indications that China might be ready with its own plan, although many experts say they will be skeptical until Chinese officials reveal the details. A senior Chinese official said his country would try to reach a peak level of carbon emissions "as early as possible." This suggests the Chinese government, struggling with air pollution so extreme that it has threatened economic growth, regularly kept millions of children indoors and ignited street protests, was determined to show faster progress in curbing emissions. In recent years, the Chinese government has sent other signals about addressing carbon pollution, some of them encouraging to environmental experts. "Five years ago, it was almost unimaginable to discuss China putting a cap on carbon, but now that is happening," said Lo Sze Ping, chief executive officer of the World Wildlife Fund's office in Beijing. "Chinese leaders have seen that it is imperative to move toward a low-carbon economy."