Gloomy tales http://www.caglaryetiskin.com/precio-propecia-finasteride-b061.pdf preisvergleich propecia 1mg 98  So how do the climate models reach their alarming conclusions? They assume that positive feedback from water vapor will cause additional warming. The argument is that, since warmer air can hold more moisture, water vapor will increase in the atmosphere as Earth warms. Since water vapor is a greenhouse gas, additional water vapor will add additional warming to that caused by CO2.