in technology at a climate change conference earlier this month. The conference was called to explore what city governments can do to reduce air pollution, increase energy efficiency and help the environment.The mayor of Seoul told VOA that "green technology' investments are paying off for his city. He also said he is working with nearby cities to prevent toxic dust from blowing in across the border.Conference delegates heard about a number of programs and projects, such as the Mapo Resource Recovery Facility in Seoul. The facility processes 750 tons of trash every day. It turns all these unwanted materials into electricity – power equal to 41,000 barrels of oil a year. The center uses a system of filters to catch most of the carbon gases produced in the burning process.Seoul's Mayor, Park Won-soon, says investments in technology are good for the environment, the economy and the 10 million people living in the city.He says, "I think it brings more incentives that have helped us recover our health and improve our quality of life. This also works as a philosophical base for our policy."Ten years ago, the Cheonggye Stream project made repairs to the waterway that runs through Seoul. The improvements made the waterway more appealing to Seoul residents. They also helped to reduce the city's heat during the summer.Some people have criticized Seoul's modern, glass-enclosed city hall building. Critics say it looks like a tsunami wave rising high over the ocean. The building's walls are covered with plants to create oxygen. Solar equipment on top of city hall produces renewable energy.The conference delegates also heard about the Seoul Resource Center. It provides jobs and reduces the amount of trash in city landfills. The center gets back much of its operating costs by selling salvaged parts from unwanted electronic waste.Mayor Park says Seoul is working to export its expertise and technologies to other cities facing environmental problems.He says, "We have been developing various know-hows and techniques through the process of resolving such problems. I think it is very important to share these with various countries around the world."Air pollution can still be a problem in the South Korean capital. A toxic mix of desert dust and factory smog often hits Seoul when the winds blow in from China.Seoul's mayor says he reached out to 13 cities in China and Mongolia to help them fight pollution and other environmental problems.He says, "If these things progress, I think various ways will be prepared to tackle erosion and global warming by the international common effort."Mayor Park Won-soon says Seoul can do its part to limit the effect of rising temperatures on Earth's surface. But he says no city can do it alone in this interconnected world.更多听力请访问51voa.com