A workshop † † Participants at the workshop were: J. Alcamo (IIASA), S. Chernavsky (Institute of Long-term Forecasting, U.S.S.R.), B. Döös (IIASA), B. Eliasson (Asea Brown Boveri, Switzerland), G. Esser (IIASA), Y. Fujii (University of Tokyo), A. Gheorghe (International Atomic Energy Agency, Austria), P.-V. Gilli (Technical University of Graz), A. Grübler (IIASA), A. Hackl (Austrian Academy for Environment and Energy), C. Hendriks (University of Utrecht), A. Inaba (IIASA), P. de Jánosi (IIASA), A. John (IIASA), T. Kashiwagi (Tokyo University of Agriculture and Technology), Y. Kaya (University of Tokyo), O. Kobayashi (Global Industrial and Social Progress Research Institute, Japan), T. Kram (Energy Research Foundation, The Netherlands), J. Kuyper (Shell International Petroleum Co., Ltd., U.K.), T. Lis (Institute of Fundamental Technological Research, Poland), C. Marchetti (IIASA), A. Mathur (Tata Energy Research Institute, India), R. Matsuhashi (University of Tokyo), A. McDonald (American Academy of Arts and Sciences), S. Messner (IIASA), K. Nagano (lIASA), N. Nakićenović (IIASA), C. Nystedt (Asea Brown Boveri, Sweden), K. Pollak (ÖMV Aktiengesellschaft, Austria), D. Richards (U.S. National Academy of Engineering), S. Riley (IIASA), H. Saiki (Central Research Institute of Electric Power, Japan), P. Schaumann (University of Stuttgart), R. Shaw (IIASA), Y. Shindo (National Chemical Laboratory for Industry, Japan), Y. Sinyak (IIASA), J. Skea (Science Policy Research Unit, University of Sussex, U.K.), J. Spitzer (Joanneum Research, Austria), M. Styrikovich (Presidium of the U.S.S.R. Academy of Science), W. Turkenburg (University of Utrecht), O. Ullmann (Ludwig Bölkow Stiftung, Fed. Rep. Germany), D. Victor (Massachusetts Institute of Technology, U.S.), A. Voss (University of Stuttgart), and K. Yamaji (Central Research Institute of Electric Power, Japan). on CO 2 reduction and removal measures for the next century was held at the International Institute for Applied Systems Analysis (IIASA) ‡ and is briefly described. It was organized to assess carbon dioxide (CO 2) reduction and removal strategies worldwide and to review other studies and technological options being considered by leading research organizations in different countries. Policy measures for environmentally compatible development of energy systems encompass many different areas of human activities both in space and time. Accordingly, the workshop participants' affiliations and backgrounds reflected this diversity. The 48 participants represented more than 11 disciplines from academic, private and public organizations from 15 different countries both North and South. Five workshop sessions dealt with global and regional studies, national studies, efficiency improvements and cleaning (scrubbing), low and zero carbon options (including renewables), global issues and integration.