China, the world’s leading emitter of greenhouse gases from coal, has been burning up to 17 percent more coal a year than the government previously disclosed, according to newly released data. The finding could complicate the already difficult efforts to limit global warming.

Even for a country of China’s size, the scale of the correction is immense. The sharp upward revision in official figures means that China has released much more carbon dioxide — almost a billion more tons a year according to initial calculations — than previously estimated.

The increase alone is greater than the whole German economy emits annually from fossil fuels.