CANBERRA, Sept. 9 (Xinhua) -- United Nations (UN) Secretary General, Ban Ki-moon, told Xinhua Friday that he was very much impressed with China's effort on tackling climate change, and welcomed China taking a leadership role in fighting the global challenge.

Ban, who had attended the Pacific Island Forum in New Zealand, and is now visiting Canberra of Australia, said there are needs for world leaders to address global challenges including climate change, pandemics, water scarcity, energy shortages and food crisis.

He emphasized that climate change is one of the greatest threats to the security, well-being and livelihoods of the peoples of the Pacific-Asia region.

In Australia, Coalition opposing the government's proposed carbon tax believes there is no point to taking action, saying that the world's largest carbon emitters are not working to tackle the issue. However, this seems not very much the case, as Ban said China has been doing a very impressive job on fighting against climate change.

"I clearly commented highly the Chinese government initiative to increase energy efficiency by 45 percent, and I was very much impressed by such very dynamic initiative with their increasing energy efficiency," Ban told Xinhua reporter in Canberra on Friday morning.

"With the rapid progressing economy solution development, it is important that China takes leadership role in this campaign against climate change."

China had pledged to reduce its carbon pollution by up to 45 percent in the next decade, and is increasing its lead over the U. S. in clean energy investment. Ban referred to his speech in Sydney University on Thursday's night, saying that China's move could encourage a breakthrough in global negotiations.

"These actions are vital on their own, but they can also inspire progress in the global negotiations, creating a virtuous cycle," he said.

Meanwhile, Ban was also critical of climate skeptics, insisting that the science of global warming is clear and a failure to act would see increasing numbers of people affected by rising sea levels and extreme weather events.

"Very clearly that something is happening much more faster than you may think. A group of at least 2,000 distinguishing scientists from inter-government panel for climate change said their conclusion is very clear that climate change is happening."

Ban will leave Australia later on Friday, ending his one week visit in Asia Pacific region.