(AP) -- Renewable sources such as solar and wind could supply up to 80 percent of the world's energy needs by 2050 and play a significant role in fighting global warming, a top climate panel concluded Monday.
But the U.N. Intergovernmental Panel on Climate Change said that to achieve that level, governments would have to spend significantly more money and introduce policies that integrate renewables into existing power grids and promote their benefits in terms of reducing air pollution and improving public health.
Authors said the report concluded that the use of renewables is on the rise, their prices are declining and that with the right policies, they will be an important tool both in tackling climate change and helping poor countries use the likes of solar or wind to develop their economies in a sustainable fashion.
"The report shows that it is not the availability of the resource but the public policies that will either expand or constrain renewable energy development over the coming decades," said Ramon Pichs, who co-chaired the group tasked with producing the report. "Developing countries have an important stake in this future - this is where 1.4 billion people without access to electricity live yet also where some of the best conditions exist for renewable energy deployment."
Governments endorsed the renewable report Monday after a four-day meeting. The nonbinding scientific policy document is to advise governments as they draw up policies and to help guide the private sector as it considers areas in which to invest.
Greenpeace and other environmentalists said Saudi Arabia and Qatar, two oil-rich states that don't have an interest in alternatives, successfully watered down the report's language on the cost benefits of renewables - a charge the Saudis denied, saying they only were arguing to stick with the science. Brazil, a major ethanol producer, opposed language on the negative effects of biofuels and hydro as well as the economic potential of other renewables.
The report reviewed bioenergy, solar energy, geothermal, hydropower, ocean energy and wind. It did not consider nuclear, so IPCC chairman Rajendar Pachauri said the recent nuclear accident in Japan was not discussed nor did it have any impact on the report's conclusions.
The IPCC has said swift, deep reductions in use of non-renewables are required to keep temperatures from rising more than 3.8 degrees Fahrenheit (2 Celsius) above preindustrial levels, which could trigger catastrophic climate impacts.
Stephan Singer, director for Global Energy Policy at WWF International, welcomed the report but said the IPCC should have gone further. He said its studies have found that the world could be fueled 100 percent by renewables by 2050.
"IPCC delivers a landmark report that shows the rapid growth, low-cost potential for renewable energy - but unfortunately does not endorse a 100 percent renewable energy pathway until 2050," Singer said in a statement. "We need to be fast if we want to tackle pressing issues as varied as energy security and efficiency and at the same time keep climate change well below the danger threshold of 2 degrees."
Greenpeace's Sven Teske agreed. "This is an invitation to governments to initiate a radical overhaul of their policies and place renewable energy center stage," he said. "On the run-up to the next major climate conference in South Africa in December, the onus is clearly on governments to step up to the mark."
Adnan Amin, the director general of the International Renewable Energy Agency which is based in Abu Dhabi, said the report "shows there is a growing global awareness about the potential for renewable energy" which he made clear has taken off in recent years.
From 2009 to 2010, Amin said investment in renewables has gone from $186 billion to $243 billion with China alone seeing a 30 percent increase. He said research and development in the sector has seen "record growth."
"These are remarkable figures for a sector still emerging," Amin said. "Where it points is some of the conclusions that the IPCC is coming to. We are seeing through research and development the technologic possibilities increasing and costs coming down and feasibility of investment in renewable energy increasing by the day. The opportunities are tremendous."
But the IPCC warned that further development of the sector will require significant investment in the next two decades - of as much as $1.5 trillion by 2020 and up to $7.2 trillion from 2020 to 2030.
"The deployment and development of renewables requires development of new infrastructure, otherwise we will not see further growth of renewables," said another of the report's co-chairs Ottmar Edenhofer.
Explore further: NREL releases the 2013 Renewable Energy Data Book, detailing increases in installed capacity