Panel chief says prediction of Himalayan glaciers' disappearance by 2035 was erroneous.

False prediction used in report was "regrettable error", says chairman of UN body.

Singer says world leaders must address impact of beef production at climate talks.

Scientist believes diet change important in reducing greenhouse gas emissions.

UN panel finds global warming's impact accelerating and potentially irreversible.

Evidence that humans are to blame for global warming is rising but governments are doing too little to counter the threat, the head of the United Nations climate panel says.