The world needs to redouble efforts to fight climate change ahead of global talks in Durban, with time running out to save millions of lives in countries to be hit hardest, United Nations Secretary-General Ban Ki-moon said on Thursday, according to Reuters.

Ban, winding up a visit to Australia and small Pacific nations including several likely to be swamped by rising sea levels, said critics of climate change science were wrong.

"The facts are clear. Global greenhouse gas emissions continue to rise. Millions of people are suffering today from climate impacts. Climate change is very real," Ban said in a speech at Sydney University.

"Environmental migrants are starting to reshape the human geography of the planet. This will only increase as sea-levels rise and deserts advance. We cannot burn our way to the future," he said.

Hopes have dimmed for a new global climate pact to replace the Kyoto Protocol, which expires at the end of 2012, after U.S. President Barack Obama and other leaders failed to agree in Copenhagen in 2009 on a new deal limiting global warming.

Leaders of 193 countries are set to meet for the next annual U.N. climate summit in November in Durban, where talks could stall again if rich and poor nations renew squabbling over how to share out emissions cuts and whether to extend the existing protocol.

Ban rejected criticism that little progress had been made so far in several rounds of global climate talks, most recently in Mexico, which he said had delivered climate adaptation measures to protect vulnerable people.

The Durban conference must keep building on that progress, he said, and agree to ambitious mitigation targets that would ensure any increase in global average temperature remained below 2 degrees Centigrade.

"Moreover, given that the first commitment period of the Kyoto Protocol expires next year, a political formula must be found to ensure that a robust, post 2012 climate regime is agreed upon, and is not delayed by negotiating gamesmanship," Ban said.

He said many countries were already taking steps to combat climate shift.

China had pledged to reduce carbon intensity by up to 45 percent and now led the United States in clean-energy capacity, he said, while India was planning to lift clean energy investment by more than 350 percent in this decade.

"These actions are vital on their own, but they can also inspire progress in the global negotiations, creating a virtuous cycle. My advice to you. Be bold. Be brave. Think big," he said.

Australian`s government has also taken measures to fight climate change and unveiled plans two months ago to impose a tax on carbon emissions from July 2012, before moving to a carbon trading system from mid-2015.

European Commission President Jose Manuel Barroso said on Monday after talks with Australian Prime Minister Julia Gillard that Europe and Australia aimed to link their trading schemes.

Ban said he had seen for himself this week in the tiny island nation of Kiribati how fears of rising seas and swamping tides were terrifying local people, while the drought crisis and conflict in the Horn of Africa had put 12 million lives at risk.

The U.N. climate chief Christiana Figueres told Reuters last month governments were very much "on track" to deliver on the main commitments agreed at a Mexico summit last year, related to finance, technology and climate adaptation.

At the 2010 talks in Cancun, governments agreed to set up a Green Climate Fund to manage $100 billion a year by 2020 in aid to the poor nations most at risk of climate change.

By Pauline Askin, Reuters