LOS ANGELES - Los Angeles, London, New York, Seoul and 18 other cities joined forces on Tuesday in a global warming project aimed at reducing greenhouse gas emissions.

Former U.S. President Bill Clinton speaks before the announcement of a partnership between the Clinton Climate Initiative (CCI) and the Large Cities Climate Leadership Group at UCLA Korn Convocation Hall in Los Angeles August 1, 2006. The Large Cities Climate Leadership Group aims to reduce energy use and greenhouse gas emissions in an effort to slow global warming.[Reuters]

Launched by former President Bill Clinton's foundation, the initiative will allow cities to pool their purchasing power and lower the price of energy-saving products and provide technical assistance to help them become more energy efficient.

Urban areas are responsible for more than 75 percent of all greenhouse gas emissions, making reduced energy crucial in the effort to slow the pace of global warming.

Energy-efficient traffic lights, street lighting, the use of biofuels for city transport, and traffic congestion schemes were some of the practical steps that cities are expected to take to reduce greenhouse gases.

"The world's largest cities can have a major impact on this. Already they are at the center of developing the technologies and innovative new practices that provide hope that we can radically reduce carbon emissions," said London Mayor Ken Livingstone, who launched the initiative in Los Angeles with Clinton and British Prime Minister Tony Blair.

The Clinton Foundation said it hoped that coordination between major cities will boost efforts now being made by some areas on an individual basis.

The partnership with the foundation began with the participation of 22 cities -- Berlin, Buenos Aires, Cairo, Caracas, Chicago, Delhi, Dhaka, Istanbul, Johannesburg, London, Los Angeles, Madrid, Melbourne, Mexico City, New York, Paris, Philadelphia, Rome, Sao Paulo, Seoul, Toronto and Warsaw.