Talks in Paris aimed at reaching a global climate accord entered a fraught new phase yesterday, even as research showed the carbon dioxide emissions that the agreement is supposed to cut have unexpectedly stalled.

It was already known that emissions from burning fossil fuels barely grew last year. But preliminary estimates from an international group of scientists show they may have fallen by 0.6 per cent in 2015.

That would be a dramatic turnround from the 2-3 per cent annual emissions growth recorded since 2000 and a rare occurrence in a year when the International Monetary Fund expects the global economy to grow by about 3 per cent. Global emissions normally fall only when economic crises slow the power plants and factories that pump out carbon pollution.