Positive water vapor feedback is when CO2 is burned into the atmosphere, causing the temperatures to rise. Water vapour is also the dominant positive feedback in our climate system and a major reason why temperature is so sensitive to changes in CO2. The water-vapour feedback and the lapse-rate feedback can combine their effects. The IPCC manufactures climate alarm by assuming CO2 controls water vapor to produce a runaway positive feedback system. This water vapour feedback is simply written into climate models as parameters. An important example is the water vapor feedback loop. Since water vapor is a greenhouse gas, the increase in water vapor content makes the atmosphere warm further; this warming causes the atmosphere to hold still more water vapor (a positive feedback), and so on until other processes stop the feedback loop. A new paper finds that observations of atmospheric water vapor show a decrease with global warming, leading to a negative feedback on global temperature, not positive as assumed by alarmist IPCC computer model projections. As other greenhouse gases like CO2 warm the planet, the atmosphere can hold more water vapor. One of the main determinants is whether water vapor will be a positive (warming) or negative (cooling) feedback. And since water vapor is itself a greenhouse gas, the increase in … In fact, if it weren't for the water vapor feedback, it really wouldn't be as much of a global warming problem at all. One of the main determinants is whether water vapor will be a positive (warming) or negative (cooling) feedback. So you had too much to start with, it would relax back down to that equilibrium value. The errors associated with this calculation, associated primarily with the shortness of our observational time series, suggest that the long-term water vapor feedback lies between 1.9 and 2.8 W m-2 K–1. If the temperature increases more in the upper troposphere causing a negative lapse-rate feedback, the warming will also be associated with higher concentrations of water vapour in a region where it has a large radiative impact, leading to an additional positive water-vapour feedback. Using our technique, we calculate a short-term water vapor feedback of 2.2 W m–2 K–1. Water vapor forms clouds, certain types of … Unlike external forcings such as CO2 which can be added to the atmosphere, the level of water vapour in the atmosphere is a function of temperature. Because water vapor is a greenhouse gas, this results in further warming and so is a "positive feedback" that amplifies the original warming. Over in another article, a commenter claims: ..Catastrophic predictions depend on accelerated forcings due to water vapour feedback. It is not derived from any kind simulation of first principles in the General Circulation Model runs (GCMs).. [Emphasis added] I've seen this article of… The amount of water vapor feedback is important to climate science circles. Similarly, water vapor serves as a feedback to temperature changes catalyzed by anthropogenic greenhouse gas emissions. Water vapor itself cannot force changes in the climate, due to its short atmospheric lifetime, but atmospheric water vapor concentrations respond to and amplify temperature changes. This is what scientists call a “positive feedback.” Figure courtesy of Carl Mears and Frank Wentz/ positive feedback loops will accelerate a response, making the climate much warmer or colder. With virtually all scientists (including 'skeptics' like Christy and Lindzen) in agreement that humans are causing global warming, the main scientific question is how much will our greenhouse gas emissions cause the planet to warm in the future. Higher, warmer temps mean MORE water vapor.