New Delhi, Aug. 21 -- High on the Tibetan plateau, Chinese government officials last month showed off what they say will be the world's largest solar farm when completed - 610 square kilometers (235 square miles), the size of the American city of Chicago.

China has been installing solar panels at a blistering pace, far faster than anywhere else in the world, and the investment is starting to pay off. A study released Thursday found that the country's carbon emissions edged down 1% in the first six months of the year compared to a year earlier, extending a trend that began in March 2024.

The good news is China's carbon emissions may have peaked well ahead of a government target of doing so before 2030. But China, the world's biggest emit...