London: World temperatures are likely to rise by more than two degrees Celsius this century, surpassing a "tipping point" that a global climate deal aims to avert, scientists said on Monday.

A study published in the journal Nature Climate Change shows a 90 per cent chance that temperatures will increase this century by 2 to 4.9 degrees Celsius.

Researchers at the University of Washington found only a five per cent chance that warming could be at or below two degrees Celsius – one of the targets set by the 2015 Paris climate deal on limiting emissions of greenhouse gases that warm the planet.

Missing that target would have dramatic consequences on people's livelihoods – such as prolonged periods of drought and rising sea levels – said Adrian Raftery, the lead author of the study and a professor at the University of Washington.