Extreme weather is the new normal and poses a threat to the human race, U.N. Secretary-General Ban Ki-moon said on Tuesday as he sought to revive deadlocked global climate change talks.

Ban's intervention came as efforts to agree a symbolic extension of the U.N. Kyoto Protocol, a treaty that obliges about 35 developed nations to cut their greenhouse gas emissions until the end of 2012, looked to be faltering.

UN Chief Ban Ki-moon at Doha. Credit:AFP

In a speech to almost 200 nations meeting in Doha to try to get a breakthrough, Ban said a thaw in Arctic sea ice to record lows this year, superstorms and rising sea levels were all signs of a crisis.

"The abnormal is the new normal," he told delegates at the November 26-December 7 talks. He said signs of change were apparent everywhere and "from the United States to India, from Ukraine to Brazil, drought (has) decimated essential global crops".