The nuclear power industry said on Thursday it provided a clean alternative to fossil fuels and a global warming crisis, shrugging off environmentalist concerns about nuclear waste and atomic security.

The term renaissance was the buzz word as nuclear industry players emerged from the 21-year-long shadow of the Chernobyl nuclear disaster and gathered in London for two days of talks at the 32nd annual symposium of the World Nuclear Association.

Nuclear power is now a fully competitive electricity source, said WNA chairman Ralf Gueldner. Today we see the nuclear renaissance begin to reach full bloom.

Nuclear power now provides 16 percent of a world electricity demand predicted to at least keep pace with the 50 percent growth in population expected by 2075 -- and nuclear optimists see that share rising.

Gueldner said he even expected his own country Germany to reverse its current policy of phasing out nuclear power plants.

Scientists predict that global average temperatures will rise by between 1.8 and 4.0 degrees Celsius this century due to carbon gases from burning fossil fuels for power and transport, bring climatic and humanitarian disasters.

As the world wakes up to the threat governments are seeking to curb carbon emissions through clean sources of power that do not harm economic growth.

The nuclear power industry, despite environmentalists' worries about security, nuclear weapons proliferation and the fact that nuclear waste remains deadly for thousands of years, sees itself as an obvious choice.

The prospects for nuclear energy are more promising today than at any time since its development, said Dennis Spurgeon, U.S. Assistant Secretary for Nuclear Energy, who also termed it a global renaissance.

There is now a worldwide momentum for the expansion of nuclear power.

At present there are some 429 reactors operating globally, with 25 more under construction, 76 planned and 162 proposed.

Coal-rich China, which is building a coal-fired power station a week to fuel its booming economy, has also embarked on a major nuclear power program.

International Atomic Energy Agency head Mohamed ElBaradei said nuclear power had a role with 1.6 billion people without any access to electricity and the developed world using 170 times more electric power than the developing nations.

But he said the world had to guard relentlessly against the dangers of weapons proliferation.

Nuclear power can't be an exclusive solution for wealthy nations, he said. But the challenges of introducing nuclear power in developing countries are formidable.

Environmentalist James Lovelock, who outraged the green movement several years ago by saying nuclear power had a role to play, introduced a more somber note to the gathering.

World systems are already in failure mode, he said. The world itself is in no danger and we as a species will probably survive. What is at risk is our civilization.

Cutting carbon emissions would, like a kidney failure patient on dialysis, buy time. But temperatures would inevitable rise bringing floods and famines and forcing the surviving humans into isolated areas until the planet recovered.