Resignation gives UN opportunity to reinvigorate talks following Copenhagen summit
De Boer will leave the UNFCCC in July to take up a role at KPMG
Official figures show greenhouse gas emissions fell nearly two per cent in 2008 as a result of recession and green policies
He Yafei shifted from position in foreign ministry after clashing with Obama and Merkel at Copenhagen
Prime minister says he has a plan that will bolster chances of global climate change deal over next few months
The Guardian asks leading climate change experts for their assessment of the Copenhagen deal
In the end it came down to frantic horse trading between exhausted politicians
Responses to Copenhagen deal range from cautious optimism to outright despair