Mass balance inverse modelling of methane in the 1990s using a Chemistry Transport Model T. M. Butler , I. Simmonds, and P. J. Rayner School of Earth Sciences, Melbourne University, Australia CSIRO Atmospheric Research, Melbourne, Australia Present affiliation: Max Planck Institute for Chemistry, Mainz, Germany Received: 7 April 2004 – Accepted: 24 May 2004 – Published: 22 June 2004 Corresponde...