A U.N. report on rising greenhouse gas emissions reminded world governments on Wednesday that their efforts to fight climate change are far from enough to meet their stated goal of limiting global warming to 2°C (3.6°F).

The report by the U.N. Environment Programme, released just days ahead of a major climate conference, said the concentration of heat-trapping greenhouse gases like carbon dioxide in the atmosphere is up about 20 per cent since 2000.