Urban ecology in temperate climates. Greenhouse gas emissions include those of carbon dioxide and methane from the combustion of fossil fuels to supply energy needed by vast urban metropolises. Other greenhouse gases include water vapor, and nitrous oxide. Increases in greenhouse gases due to urban transport, construction, industry and other demands have been correlated strongly with increase in temperature. Sources of methane are agricultural dairy cows and landfills. Processes related to urban areas result in the emission of numerous pollutants, which change corresponding nutrient cycles of carbon, sulfur, nitrogen, and other elements. Ecosystems in and around the urban center are especially influenced
Chicago Climate Exchange were intended to still be facilitated. Until July 2010, CCX was operated by the public company Climate Exchange PLC, which also owned the European Climate Exchange. Richard Sandor, creator of the Sustainable Performance Group, founded the exchange and has been a spokesman for it. The exchange traded in emissions of six gases: carbon dioxide, methane, nitrous oxide, sulfur hexafluoride, perfluorocarbons, and hydrofluorocarbons. CCX started trading in October 2003, prior to the commencement of trading in the European Union through the ETS system. IntercontinentalExchange (), a leading operator of regulated global futures exchanges, clearing houses and over-the-counter (OTC) markets, announced in