Global warming worries to boost renewables

By Alister Doyle, Environment Correspondent

OSLO (Reuters) - Three decades after former U.S. President Jimmy Carter experimented with solar panels on the White House roof, grim U.N. warnings about climate change may kick-start wider global use of renewable energy.

"The political willingness to act is now significantly higher," Achim Steiner, head of the U.N. Environment Program (UNEP), told Reuters.

Governments from Japan to Germany are already subsidizing energies such as wind, hydro, biofuels, geothermal, solar or tidal power, spurred by worries about security of supply, climate change and high oil prices at about $60 a barrel.

Steiner said warnings by the world's top climate scientists in a February 2 report that blamed mankind more clearly than ever for causing global warming -- mainly by emitting greenhouse gases from burning fossil fuels -- would be a big new spur.

"This will change the variables, renewable energies will become a more significant part of our energy mix," he said.

Past waves of optimism for renewables, such as during an energy crisis in the 1970s under Carter, foundered on technological barriers and a lack of competitiveness when oil prices fell below $10 in the mid-1980s.

Many experts also warn against exaggerated hopes this time, despite increasing public pressure to act.

"There will be a push for renewable energies, but they have limitations," said Fatih Birol, chief economist of the International Energy Agency (IEA), which advises governments in developed nations. Windmills cannot generate electricity on still days, for instance, and solar power doesn't work at night.