Climate change could have a "huge impact" on China, reducing crop yields and harming the environment, the country's top weather scientist has warned, in a rare official admission.

Zheng Guogang told Xinhua news agency that climate change could be a "serious threat" to big infrastructure projects.

He said temperature rises in China were already higher than global averages.

China, the world's biggest polluter, has said its emissions of gases that cause climate change will peak by 2030.

However, the country has not set a specific target for cutting emissions of the gases, mainly carbon dioxide.

'Emphasise climate security'

Zheng, the head of China's meteorological administration, said warming temperatures exposed his country to a growing "risk of climate change and climate disasters".

He said temperature rises in China had already been higher than the global average for the past century.

These are rare admissions from a Chinese official, BBC Asia analyst Michael Bristow says.

China's leaders have acknowledged the damage from global warming but they usually do not lay out the full scale of the problems.

Zheng warned of more droughts, rainstorms, and higher temperatures, which would threaten river flows and harvests, as well as major infrastructure projects such as the Three Gorges Dam. He urged China to pursue a lower-carbon future.

"To face the challenges from past and future climate change, we must respect nature and live in harmony with it," the Xinhua news agency quoted him as saying.

"We must promote the idea of nature and emphasise climate security."

China and the US together produce around 45% of global carbon emissions.

Leaders from the two countries are taking part in a summit in Paris this year that will aim for a global deal to cut carbon emissions by 2020.

China's decades-long pursuit of rapid economic growth has boosted demand for energy, particularly coal.

Scientists fear that pledges made so far to cut emissions will not be enough to avoid the harmful impact of climate change