The world has five years to start a "low carbon industrial revolution" before runaway climate change becomes almost inevitable, according to a new report commissioned by global conservation group WWF.
Beyond 2014, the upper limits of industrial growth rates will make it impossible for market economies to meet the lower carbon targets required to keep global warming below 2 degrees Celsius, said the report by Climate Risk Ltd, which provides assessments on climate change risk, opportunities and adaptation.
A global temperature rise from carbon emissions of two degrees Celsius has been identified by scientists as presenting unacceptable risks of runaway climate change.
"In highlighting the critical nature of the time constraint, the report also shows that the current emphasis on carbon price as the key element of the climate change solution is dangerously misleading," said co-author Karl Mallon.
The "Climate Solutions 2" report found market measures, such as emissions-trading schemes like the one in operation in Europe and planned by Australia, will not by themselves deliver a sufficient reduction in emissions in time.
Beyond 2014, "war-footing paced interventions" could be introduced to bring about rapid transition, but the report warns against relying on such action.
"We have reached a pivotal moment in our history where the window of opportunity which remains to prevent runaway climate change will soon disappear entirely," said Kim Carstensen, leader of WWF's Global Climate Initiative.
UN climate talks on expanding the fight against global warming have largely stalled ahead of a major climate summit in Copenhagen.
Currently, emissions reduction targets are far below the 25-40 percent cut from 1990 levels by 2020 the UN climate panel says is needed to limit the growth of carbon in the atmosphere.
The WWF report called for simultaneous action on greenhouse emissions from all sectors, using market measures and other policies such as energy efficiency standards, feed-in tariffs for renewable energy and an end to subsidies for fossil fuel use.
"The transformation will require sustained growth in clean and efficient industry in excess of 20 per cent a year over a period of decades," Mr Carstensen said in a statement.
"The report's modelling shows how we can sustain these growth rates but also makes it clear this will be the fastest industrial revolution witnessed in our history."
Industries that will lead the transformation are renewable energy, carbon capture and storage, energy efficiency, low-carbon agriculture and sustainable forestry, said the report.
A "clean industrial revolution" could see renewable energies become competitive with fossil fuels between 2013 and 2025 based on a two per cent annual rise in fossil fuel prices and no price on carbon, it said.