The pace of climate change is accelerating and the world's governments must fast-track a policy move from fossil fuels to greater reliance on renewable energy, a global report says.
It warns climate change is happening much faster than predicted and many aspects of the Earth's climate including rising temperatures and frequency of extreme weather events are already moving well ''beyond the patterns of natural variability''.
The challenge requires governments to adopt ''aggressive mitigation portfolios'' to cut rising greenhouse emissions. These should include ambitious emission reduction targets, greener transport systems, smarter energy grids, increased support for sustainable farming systems, and a massive investment boost to fund production of renewable energy technologies.
The 36-page report, published by the University of Copenhagen, is based on 1600 scientific contributions to a global climate summit in Denmark held three months ago. It was tabled yesterday at the European Policy Centre in Brussels and outlines the updated economic and environmental implications of the latest climate research.
The report, compiled by 12 of the world's leading experts, including British economist Sir Nicholas Stern, warns if governments set weak emission reduction targets for 2020, it will increase the risk of impacts ''including the crossing of tipping points, and make the task of meeting 2050 targets more difficult ...''
One of the report's co-authors, Australian National University climate centre director Professor Will Steffen, said new scientific evidence pointed to an increasing risk of abrupt or irreversible climate shifts.
''We are running out of time to get emissions tracking downwards, because changes to the climate system are moving much faster than we anticipated,'' he said.