Atmosphere of Earth However, polar stratospheric or nacreous clouds are occasionally seen in the lower part of this layer of the atmosphere where the air is coldest. The stratosphere is the highest layer that can be accessed by jet-powered aircraft. The troposphere is the lowest layer of Earth's atmosphere. It extends from Earth's surface to an average height of about , although this altitude varies from about at the geographic poles to at the Equator, with some variation due to weather. The troposphere is bounded above by the tropopause, a boundary marked in most places by a temperature inversion (i.e. a layer of
Live Earth (2007 concert) the crowd "motherfuckers". The BBC later apologised for cutting away from footage of Metallica, and both during and after the concert for the bad language. On 12 April 2008, an Ofcom broadcast was shown on BBC1, apologising again for the 'offensive language.' Intelligent Giving have attempted to find out what was happening to the proceeds from ticket sales at the concerts. Their conclusions, published in a feature "What on (Live) Earth is going on?" were that no one involved is capable of giving a clear answer. Live Earth was documented on "Live Earth: The Concerts for a Climate in Crisis",