Video on the UN-Water Interview Session at Deutsche Welle Global Media Forum (Bonn, Germany), 20 June 2011. This session was organized by the United Nations Office to Support the International Decade for Action "Water for Life" 2005-2015/UN-Water Decade Program on Advocacy and Communication (UNW-DPAC), in collaboration with UN-Habitat, the UN-Water Decade Program on Capacity Building (UNW-DPC) and the Water Supply and Sanitation Collaborative Council (WSSCC). During the session, the panel and the audience discussed about the UN resolution, the aspect of sanitation, the country example of South Africa and experiences and opinions from the audience.
As a gas, water vapor is completely miscible with air. On the other hand, the maximum water vapor pressure that is thermodynamically stable with the liquid (or solid) at a given temperature is relatively low compared with total atmospheric pressure. For example, if the vapor's partial pressure is 2% of atmospheric pressure and the air is cooled from 25 °C, starting at about 22 °C water will start to condense, defining the dew point , and creating fog or dew . The reverse process accounts for the fog burning off in the morning. If the humidity is increased at room temperature, for example, by running a hot shower or a bath, and the temperature stays about the same, the vapor soon reaches the pressure for phase change, and then condenses out as minute water droplets, commonly referred to as steam.