REPRESENTATIVES from more than 20 of the world's major cities are meeting in London today to discuss climate change.

The World Cities Leadership Climate Change Summit will discuss ways of addressing what London Mayor Ken Livingstone said were the "inevitable effects" of climate change.

Those taking part in today's event include - London, Barcelona, Beijing, Berlin, Brussels, Chicago, Curitiba, Delhi, Florida, Kingston, Madrid, Melbourne, Mexico City, New York, Paris, Philadelphia, Rome, Saint Denis, San Francisco, San Paulo, Shanghai, Stockholm, Toronto, Victoria, Zurich.

Mayors and senior figures from the cities will exchange ideas and develop strategies to tackle the effects of climate change.

World experts including Sir David King and Jaime Lerner, will address the meeting.

A dozen smaller cities will also show how they are already tackling the problem.

Mr Livingstone said: "Large cities are among the most significant sources of greenhouse gas emissions in the world the percentage of world energy use accounted for by cities in 2005 is 75 per cent.

"But it is also at the city level that innovation and progress on climate change action are most likely to be achieved.

"This week's conference brings together those city leaders who are taking the most productive and radical steps to adapt to and mitigate climate change, to share ideas and provide leadership to the rest of the world."

Steve Howard, chief executive of The Climate Group, said: "More than half of the world's population now lives in cities.

"We are fast becoming an urban world and so cities must play a pivotal role in leading on climate change action if we are to combat this problem. We will not be able to solve climate change without cities taking a central role.

"Cities are already reducing emissions, improving their transport systems and greening their energy use. This makes environmental as well as financial sense. The City Summit should add significant momentum to the scaling up of these actions, which The Climate Group wholly supports and welcomes."