IPCC report calls for fossil fuels to be phased out by 2100

The unrestricted use of fossil fuels must be phased out by 2100 if dangerous climate change is to be avoided, according to a UN-backed expert panel.

A report released on Sunday by the Intergovernmental Panel on Climate Change (IPCC) says that most of the world's electricity can - and must - be produced from low-carbon sources by 2050 or there will be "severe, pervasive and irreversible" damage.

The Synthesis Report was launched in Copenhagen, after a week of intense debate between scientists, experts and government officials.

The report is designed to inform politicians in their attempt to deliver a global treaty on climate change at the UN Climate Change Conference COP21 in Paris at the end of 2015.

The document explains that cutting emissions is crucial if global warming is to be limited to 2°C - a target recognised in 2009 as the threshold of dangerous climate change.

The IPCC suggest that renewable energy needs to grow from its current 30 per cent share to 80 per cent of the power sector by 2050.

The report highlights that fossil fuel power production without carbon capture and storage (CCS) technology needs to be "phased out almost entirely by 2100".

The Synthesis Report summarises three previously published reports from the IPCC, which outlined the causes, impacts and the possible solutions to climate change.

Some key elements the report outlines include how the human influence on climate is clear; the period from 1983 to 2012 was probably the warmest 30 year period of the last 1,400 years; warming impacts are already being seen in the acidification of the oceans, the melting of arctic ice and poorer crop yields; without concerted action on, temperatures will increase over the coming decades and could be almost 5°C above pre-industrial levels by the end of this century.

Ban Ki-moon, Secretary-General of the UN, said: "Science has spoken. There is no ambiguity in their message. Leaders must act. Time is not on our side. There is a myth that climate action will cost heavily. But inaction will cost much more."

Ed Davey, the UK Secretary of State for Energy and Climate Change said the report was the "most comprehensive, thorough and robust assessment of climate change ever produced. It sends a clear message that should be heard across the world - we must act on climate change now. It's now up to the politicians - we must safeguard the world for future generations by striking a new climate deal in Paris next year," he said.

Professor Myles Allen, a member of the IPCC core writing team, said: "We can't afford to burn all the fossil fuels we have without dealing with the waste product which is CO2 and without dumping it in the atmosphere. If we can't develop carbon capture we will have to stop using fossil fuels if we want to stop dangerous climate change."