RENEWABLE energy sources, including solar power, wind, biomass and hydropower could meet nearly 80 per cent of the world's energy supplies by 2050 if governments pursue policies that harness their potential, according to a new report released this week.
The United Nations-backed report presents the findings of more than 120 researchers working with the Intergovernmental Panel on Climate Change (IPCC).
The report indicates that if the path of renewable energy sources is fully followed, greenhouse gas emissions could stay low enough to keep the rise in global temperatures by the middle of the century to below 2 degrees.
The two-degree threshold is regarded as a tipping point, with a temperature rise beyond this amount likely causing the occurrence of the worst effects of climate change.
Executive Secretary of the UN Framework Convention on Climate Change (UNFCCC), Christiana Figueres, described the report as significant and said it points the way forward for governments.
"They must reach their goal by making use of renewable energy sources on a very large scale," she said.
"It is also clear that ambitious national policies and strong international cooperation are together the key to the swift and extensive deployment of renewable energies in all countries."
Ms Figueres stressed the need for appropriate finance and technology being made available to poor countries, which are expected to see the largest growth in energy generation in the decades ahead.
The report includes a review of more than 160 different scientific scenarios based on different levels of renewable energy sources and varying environmental and social factors. Four scenarios reflecting the full range of possibilities were analysed in depth.
The most optimistic of the four scenarios projects that renewable energy sources could account for as much as 77 per cent of global energy demand by 2050. In 2008, renewable energy accounted for just below 13 per cent of global energy demand.
While the report concludes that renewable energy sources will increase even without enabling policies, it notes that past experiences show that the largest increases come with concerted policy efforts.
The report also states that the costs of many renewable energy technologies would become more economically attractive if environmental impacts such as greenhouse gas emissions and pollutants are monetised and included in energy prices.
It was also noted that the overall costs of most renewable technologies have declined in recent years and are likely to fall further.
More information is available from the Intergovernmental Panel on Climate Change (IPCC) website at <http://www.ipcc.ch/>