 This is the VOA Special English Economics Report. Leaders and officials from more than 100 nations attended the United Nations Conference on Sustainable Development in Rio de Janeiro, Brazil. More than 40,000 activists and political and business leaders were also there. The three-day conference in June marked the 20th anniversary of the first UN Earth Summit, also held in Rio. That conference helped build support for the 1997 Kyoto Agreement to reduce greenhouse gas emissions. The Rio Plus 20 conference sought to bring attention to seven major issues. The UN says jobs, energy, and sustainable cities are of top importance. Food security, water, oceans, and dealing with disasters are other issues basic to lifting people out of poverty. The mayor of New York City, Michael Bloomberg, took part in a discussion among mayors of some of the world's largest cities. They talked about measures to cut greenhouse gases. These gases are known to trap heat and have been linked to climate change. Cities are responsible for up to 75% of the gases. Mr. Bloomberg said the world's mayors are taking the lead on issues like the environment and sustainability. He said, even as progress at the national and international level has faltered, it's fair to say that world cities have forged ahead, and the reason for that is clear, mayors. He called them the great pragmatists on the world stage and said they are directly responsible for the well-being of the majority of the world's people. He said mayors just don't have the luxury to simply talk about change and not deliver it. Mayors reported using electric vehicles, better street lighting, and improved waste management to reduce city's greenhouse emissions. Bindu Lohani is a top official with the Asian Development Bank, based in the Philippines. The bank has promised billions to sustainable development. Mr. Lohani said Asia's fast growth places heavy pressure on the environment and society. He says the bank predicts that by 2050, more than 50% of the global economy will be in Asia. Some environmental activists complained that there were many promises of action at the Rio Plus 20 conference, but few clear targets for reducing pollution and the use of natural resources. For VOA Special English, I'm Carolyn Presuti. To learn more about the Rio 20 conference, go to voaspecialenglish.com. You can also share your thoughts about the meeting and you can read, listen, and learn English with our programs and activities.