Countries must triple climate emission cut targets to limit global heating to 2C

United in Science report ahead of UN summit says climate is changing faster than forecast, and current plans would lead to 'catastrophic' global temperature rise

An assessment backed by the world's major climate science bodies has found commitments to cut greenhouse gas emissions must be at least tripled and increased by up to fivefold if the world is to meet the goals of the 2015 Paris climate agreement.

The report, launched as leaders gather at a UN climate action summit in New York on Monday, says current plans would lead to a rise in average global temperatures of between 2.9C and 3.4C by 2100, a shift likely to bring catastrophic change across the globe.