Carbon levels highest in 800,000 years, warns UN climate panel

Levels of three key greenhouse gases – carbon dioxide (CO2), methane and nitrous oxide – are at their highest in at least 800,000 years, the UN Intergovernmental Panel on Climate Change (IPCC) said Sunday in the final chapter of a landmark report. Between 1880 and 2012, the global average surface temperature has risen by 0.85 degrees Celsius, while the global mean sea level rose by 19 centimetres between 1901 and 2010, it said. The 40-page synthesis, summing up 5,000 pages of work by 800 scientists, said global warming was now causing more heat extremes, downpours, acidifying the oceans and pushing up sea levels.

Science has spoken. There is no ambiguity in the message. Leaders must act, time is not on our side.

U.N. Secretary-General Ban Ki-moon, speaking at the presentation of the climate report in Copenhagen

World climate change