Michael P. Doukas Richard Kessler Terrence M. Gerlach Kenneth A. McGee 1997 Gases from volcanoes give rise to numerous impacts on climate, the environment, and people. U.S. Geological Survey (USGS) scientists are inventorying gas emissions at many of the almost 70 active volcanoes in the United States. This effort helps build a better understanding of the dynamic processes at work on the Earth's surface and is contributing important new information on how volcanic emissions affect global change. application/pdf 10.3133/ofr97262 en U.S. Geological Survey, Impacts of volcanic gases on climate, the environment, and people reports