The mayors attending an international conference on climate change in Mexico City on Sunday agreed that cities in the world should work with each other and local governments to fight against the climate change.

Mayors display the signed agreements during the World Mayors Summit on Climate Change in Mexico City, Mexico, Nov. 21, 2010. [Xinhua]

Patrick Hays, the mayor of North Little Rock in the U.S. Arkansas state, told Xinhua on the sidelines of the Mayor's World Climate Change Summit (CCLIMA) 2010 that environmental protection is a shared responsibility between international, national, regional and local levels.

"As a mayor of a city, I have the most responsibility to let the citizens live better lives. We can also help our neighbor cities in emission reduction," he said.

Hays said the world has no time to waste on waiting for the national governments to make progress in greenhouse emission reduction, the cities can cooperate with each other to reduce carbon emissions, enhance energy efficiency and increase use of renewable energies.

Nearly 140 mayors from 43 countries and regions across the world signed a pact on Sunday at the meeting, pledging to reduce the greenhouse gas emissions.

Franklin Cownie, the mayor of Des Moines in U.S. Iowa state, said that thousands of cities, local and regional governments in the world should work together to promote climate protection and share the responsibility.

He also added that awareness campaigns on climate changes to the citizens is also important.

Omar Vidal, an expert from World Wildlife Fund (WWF) Program Mexico, said that cities now play a more important role in environmental protection.

"Just as the rich countries should provide fund to the poor countries in emission reduction. The cities should help each other on the aspect including financial support and technology transfer," he said.

Vidal also gave some suggestion to the mayors in energy saving and emission reduction, including reducing transportation cost by convening video conferences, promoting waste recycling and researching and developing new energy such as solar panel.

UN Climate Change Conference in Cancun, Mexico, slated from Nov. 29 to Dec. 10, will gather leaders or their representatives from some 180 countries and regions to discuss the issues of climate change and greenhouse gas emissions.