Introduction - the Montreal Regime - a new model for international co-operation on global environmental issues? P.G. Le Prestre, et al; the scientist and the politician. stratospheric ozone chemistry, M. Molina; the story of the ozone layer - lessons learned and impacts on the future, M.K. Tolba; the role of science; the evolving UV climate, J.B. Kerr; UV-B effects on aquatic ecosystems, R. Worrest; effects of UV-B on plants and terrestrial ecosystems, M. Tevini; stratospheric ozone depletion and UV-induced immune suppression, E.C. de Fabo; effects on skin and eyes, J.C. van der Leun; UV INDEX - a tool for public response, A. O'Toole; what should be done in a science assessment, D. Albritton; commentary on presentation by Daniel Albritton, G. McBean; the role of diplomacy; the Montreal Protocol as a new approach to diplomacy, R.E. Benedick; the Montreal Protocol - a new legal model for compliance control, P. Szell; the use of trade measures in the Montreal Protocol, D. Brack; the Montreal regime - sticks and carrots, P.H. Sand; international co-operation - an example of success, J.A. Mateos; the Montreal Protocol - whose model? A. Khosla; comments on Ambassador Mateos' and Dr. Khosla's remarks, V. Buxton; the Montreal Protocol - the first adaptive global environmental regime? E.A. Parson; comments - the atmosphere as global commons, M.S. Soroos; the role of technology; technology assessment for the Montreal Protocol, S. Machado Carvalho; TEAP terms of reference, R. Van Slooten; countries with economies in transition, L. Dobo, L. Kuijpers; importance of the TEAP in technology co-operation, S. Rand, L. Singh; scientific objectivity, industrial integrity and the TEAP process, L. Kuijpers, et al; global benefits and costs of the Montreal Protocol, J. Armstrong; lessons from the CFC phase-out in the United States, E. Cook; highlights of ozone protection leadership by industry in developing countries, J. Corona, J.I. Pons; competitive advantage through corporate environmental leadership, M.G. Kerr; lessons from the Thailand leadership initiative, the Vietnam corporate pledge, and the global semiconductor agreement, Y. Fujimoto; champions of Ozone layer protection, S.O. Andersen; closing comments, G. Taylor, E.T. Morehouse. Annex 1: ozone protection chronology. Annex 2: the tenth anniversary colloquium declaration.