German Chancellor Angela Merkel - a veteran of global efforts to curb climate change - has refused to set a deadline for ending her country's use of coal.

The UK has ratified the world's first comprehensive treaty on tackling climate change, the British government said.

Climate change could push more than 100m people into extreme poverty by 2030 by disrupting agriculture and fueling the spread of malaria and other diseases, the World Bank said in a report.

Europe’s climate commissioner has said world talks must provide a “substantial answer” to global warming in two years to remain relevant, after another United Nations conference gave only modest results.