Holm Tiessen is director of the Inter-American Institute for Global Change Research (IAI) and professor on leave from the Georg-August Universit+t of G_ttingen, Germany. nbsp; Gerhard Breulmann, a terrestrial ecologist, is science officer at the IAI in S#227;o Jos_ dos Campos, Brazil. nbsp; Mike Brklacich is professor of geography and environmental studies at Carleton University in Ottawa, Canada, and chairs the IAI's scientific advisory committee. nbsp; R#244;mulo S. C. Menezes is assistant professor in the Department of Nuclear Energy at the Universidade Federal de Pernambuco, Recife, Brazil.