MEXICO CITY — Global megacities such as Mexico City, Seoul, Paris and Los Angeles are more populous than scores of countries, and devour huge amounts of energy, but they've carried no weight in United Nations climate change talks.
Next week, when envoys come together in Cancun for a follow-up session to last year's rancorous U.N. climate talks in Copenhagen, Mexico City's mayor will be on hand to trumpet how the world's great cities are finding ways to reduce the greenhouse gas emissions blamed for higher global temperatures.
Few expect the Cancun meeting to make progress toward an agreement on emissions reductions, which scientists say are critical to heading off extreme weather, crop failures and rising sea levels. But as nations dither, hundreds of cities are pledging to rein in emissions, slash energy usage, and turn to renewable energy sources.
Mayors say they see greater urgency than national leaders do.
"When there is a flood, a drought, torrential rains, those who show their face before the citizens and must offer a response are the mayors. So they are the ones who are most worried by the risks," said Marta Delgado, the environmental secretary for Mexico City.
"We're leading the way," Los Angeles Mayor Antonio Villaraigosa told a gathering of 135 mayors who met in Mexico City in anticipation of the Cancun session. "The national governments have tried to run away from their responsibility."
Organized by Mexico City Mayor Marcelo Ebrard, the World Mayors Summit on Climate became a forum not only for the initiatives cities have taken to reduce emissions but also for the frustrations the urban leaders feel at being locked out of financing for broader, deeper programs.
"Cities play an absolutely strategic role in the fight against climate change," said David Cadman, who heads Local Governments for Sustainability, a group that counts 1,200 cities, towns, counties and associations among its members.
Urban areas consume as much as 60 percent of global energy production and emit 70 percent of greenhouse gases, Cadman said. Cities now house half of the world's population but will contain two-thirds of its population by mid-century, he said.
Mayors control policies on transportation, water and solid waste management, street lighting and the energy efficiency of buildings, noted Mexico City's Delgado.
Still, mayors were left on the sidelines of the Copenhagen summit last November.
"Copenhagen was a fiasco. There was no real outcome," Kadir Topbas, the mayor of Istanbul, told his colleagues, who came from Europe, Africa, Asia and Latin America. "The planet is giving us very bad signals."
Topbas said his city, which straddles the narrow Bosphorus Strait that connects the Black Sea with the Mediterranean, is thinking of radical energy solutions for its 11 million residents, including harnessing currents in the strait to produce electricity.
Mentioning his own initiatives, Villaraigosa said Los Angeles is replacing 144,000 streetlights with efficient LED lamps, ditching diesel trucks, recycling 65 percent of its garbage and moving to become "the electric vehicle capital of the United States by the end of 2011."
"The potential of cities to reduce greenhouse gas emissions is enormous," said Cassam Uteem, former president of the Indian Ocean island nation of Mauritius.
As owners of utilities and providers of key services, he said, "cities can help change citizen behavior toward energy consumption."
Mexico City, one of the world's biggest metropolises with well over 20 million people, has cut greenhouse gas emissions by 4 percent in the past two years.
Ebrard was nominated by his fellow mayors, including those of Buenos Aires, Bogota, Johannesburg, Los Angeles, Paris and Vancouver, to represent them at the Cancun gathering, which may bring as many as 30,000 people to the coastal resort through Dec. 10.
Environmental advocates watch the activism of cities with interest even as they press for a legally binding global agreement to combat climate change.
"Some of the folks (from cities) are positioning this as, 'Well, if the international process can't deliver, then we'll replace it,'" said Jake Schmidt, the international climate policy director for the Natural Resources Defense Council, a New York-based advocacy group.
Schmidt said country leaders eventually would respond to steps by the larger cities: "Each of these local processes do encourage national leaders to take action."
But some city leaders say the lack of national and global agreement keeps their hands tied on large projects, blocking financing from development banks.
"There is, theoretically, all this money out there, but they struggle to get their hands on it," said Ian Neilson, the deputy mayor of Cape Town, the second most populous city in South Africa behind Johannesburg, referring to his fellow mayors.
Neilson said the lack of an international agreement prevents his city from carrying out plans to build a wind farm. "We in South Africa cannot access European credits without this mechanism in place," he said.
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