The role of water vapor in the Earth's climate system will be discussed at a scientific conference organized by the American Geophysical Union in Potomac, Maryland, October 12 to 15. Scientists will concentrate on developments since the last such conference five years ago, a period during which theoretical and observational advances have been made.
Water vapor is the most abundant greenhouse gas and therefore significantly affects climate.
It is involved in the global hydrological cycle, affecting both evaporation and precipitation. But, despite water vapor's importance, its distribution and variability has not been as well studied as scientists would wish. Over 80 participants are expected from the United States and abroad. At the 1995 conference, the notion that water vapor might have a negative feedback on the greenhouse effect evoked some controversy. Since then, considerable effort has been made to clarify this issue, and results will be presented at the conference.