Scientists and officials stressed the importance of innovation in urban development at the Shanghai World Expo's third forum that began in Wuxi, east China's Jiangsu province, on June 20 to 21.

"Scientific and technological innovation has become the leading force in economic and social development," said Wan Gang, minister of science and technology. "As an important carrier, the city is a main gathering place of creative elements."

Urban expansion has also brought increasing use of fossil fuels over the past 200 years, giving rise to pollution, energy shortages and global climate change, Wan said.

Renewable clean energy will replace traditional fossil energy and become the main source powering future cities, he predicted.

Such innovations are also important to improve social welfare, as well as finding solutions to challenges such as food and energy security, said Supachai Panitchpakdi, secretary-general of the United Nations Conference on Trade and Development.

Participants at the forum also included Lee Tsung-Dao, Nobel Laureate in Physics in 1957, 2005 Nobel Laureate in Physiology and Medicine Barry J. Marshall and famed Chinese agricultural scientist Yuan Longping, widely known as the "father of hybrid rice".

One of the six themed forums held during the Expo, gathering's panel of experts discussed a range of topics including how innovation can ensure the safety of cities, tackle traffic congestion, deal with epidemic outbreaks and generally improve urban life.

The first of the Expo forums was held in Ningbo, Zhejiang province between May 15 and 16 and focused on information technology and urban development.

The second session discussed "cultural heritage and urban regeneration" in Suzhou, Jiangsu province on June 12 and 13.

The latest two-day forum was co-organized by the Ministry of Science and Technology, the Executive Committee of Expo 2010 Shanghai China, the UNCTAD and the Wuxi city government.

The Shanghai World Expo is a global gathering place for fresh ideas, inventions and creations, and includes pavilions, events and forums. A total of 189 countries have sponsored pavilions at the six-month cultural gala whose theme is "Better City, Better Life".