John Ritch, the director general of the World Nuclear Association, said a 20-fold increase in the number of nuclear reactors globally was the minimum needed to meet the voracious demand for energy from fast-developing countries such as China and India.
In developed countries, around 1.4 billion people _ or 20 percent of the global population _ currently use about 80 percent of the world's energy supply, most of which is coal and oil which contribute to global warming.
But China, India and other developing countries could soon outstrip the developed world in their carbon-dioxide, or greenhouse gas, emissions, with potentially deadly results, Ritch said.
"Scientists now warn, with ever increasing certainty, that greenhouse gas emissions, if continued at the present massive scale, will yield consequences that are, quite literally, apocalyptic," Ritch told a conference on nuclear energy in Sydney, Australia.
Scientists predict that an average increase in global temperatures of just a 2 degrees Celsius (4 degree Fahrenheit) could cause increasingly severe weather patterns, droughts, flooding, species extinction, rising sea levels, widespread disease and famine.
"If those predictions hold true, the combined effect would be the death of not just millions, but billions of people, and the destruction of much of civilisation on all continents," Ritch said.
The burning of fossil fuels releases carbon dioxide into the air, which many scientists blame for rising temperatures in many parts of the world. Proponents of nuclear power say it is a cleaner alternative because it produces relatively little greenhouse gases.
Critics, however, say the risk of radioactivity and the problem of storing nuclear waste far outweighs any potential benefits, and remain opposed to its widespread use.
Currently, around 440 nuclear reactors produce around one-sixth of the world's electricity.
But a minimum of 8,800 reactors producing up to 10,000 Gigawatt hours of energy is the minimum needed to prevent a global catastrophe, Ritch said.
While renewable energy sources, such as wind and solar, can help address the world's burgeoning demand for energy, they cannot meet it alone, he said.
"Humanity cannot conceivably achieve a global clean-energy revolution without a huge expansion of nuclear power," he said. "It is time for political leaders to support the rapidly expanded use of this technology if we are to cope with a global emergency that has no borders."

Copyright APP (Associated Press of Pakistan), 2006