Atmosphere of Earth relatively warm air above a colder one), and in others by a zone which is isothermal with height. Although variations do occur, the temperature usually declines with increasing altitude in the troposphere because the troposphere is mostly heated through energy transfer from the surface. Thus, the lowest part of the troposphere (i.e. Earth's surface) is typically the warmest section of the troposphere. This promotes vertical mixing (hence, the origin of its name in the Greek word τρόπος, "tropos", meaning "turn"). The troposphere contains roughly 80% of the mass of Earth's atmosphere. The troposphere is denser than all its overlying atmospheric
Live Earth concert, Washington, D.C. Gore speak and Brooks play from what event organizers called a "JumboTron" outside the immediate viewing area. Due to last minute organizing, there were no working audio speakers that could project sound to the JumboTron viewers. Live Earth concert, Washington, D.C. The Live Earth concert in Washington, D.C., officially known as "Mother Earth", was held on the National Mall in Washington, D.C., United States and was sponsored by and held on the premises/venue of the Smithsonian's National Museum of the American Indian. It was only hours before the Washington D.C. concert was scheduled to begin that organizers were able to