This grant provides partial support for the Tenth International Symposium on Environmental Biogeochemistry. The International Symposia for Environmental Biogeochemistry, (ISEB) is an organization devoted to the advancement of the science of biogeochemistry and to its influence on the global environment. The goal of the ISEB is to disseminate scientific findings in biogeochemistry to the international scientific community, thereby fostering interdisciplinary communication and research among scientists around the globe. The field of environmental biogeochemistry is broad and encompasses a diversity of disciplines. The Tenth International Symposia is to be held 21- 24, August, 1991 in San Francisco and will have a focused theme, namely that of "Global Change and the Biogeochemistry of Radiative Trace Gases." This topic is of great concern to the international scientific community, as well as to the respective governments.