你的问题对水蒸气是很常见的一个人了解温室效应。一旦你发现水蒸气和公司的相关比例<子> 2 < /订阅>在大气中,这可能是自然的假设有限公司<子> 2 < /订阅>不能发挥了重要作用。在现实中没有这样的工作,因为公司<子> 2 < /订阅>浓度*迫使*,而水蒸气浓度是一个* *的反馈。为了说明不同,这是一个原油的类比:假设我想减肥,但我不愿减少300克的美味的巧克力蛋糕,每天我吃。看,人类的身体重量80%左右的水,我认为这个蛋糕不可能是一个问题:毕竟,我每天喝2公斤的水,所以它会更有意义,以减少!所以我每天减少1公斤水摄入量和维护我的蛋糕。几周后,我惊奇地发现,我没有失去任何重量!发生了什么事?事实证明,人体调节其含水量,我减少我的摄入量减少输出。脂肪储存不规范以同样的方式,所以蛋糕不断堆积。 It's a similar story with CO2 and water vapour: CO2 concentration in the atmosphere actually changes for a long time (decades to centures) when we release more gas. Water vapour is, in effect, self-regulating. If we could wave a magic wand and instantaneously remove all the water vapour from the atmosphere, here's what would happen: [![water removal experiment][1]][1] [(source)](http://www.realclimate.org/index.php/archives/2005/04/water-vapour-feedback-or-forcing/) Within 50 days, the water vapour is back to within 1% of where it would have been without our intervention. So, if the water vapour concentration isn't controlled by input, what is it controlled by? Temperature. The warmer the atmosphere is, the more water vapour it can hold. This means that when the temperature goes up due to increased CO2, the water vapour content also increases, which further intensifies the greenhouse effect. It's acting as a positive feedback. Since you're not the first person to ask this question (by a long way), there are already some good resources online specifically addressing the different roles of water vapour and CO2 in global warming. * ["Common Climate Misconceptions: The Water Vapor Feedback"](http://www.yaleclimateconnections.org/2008/02/common-climate-misconceptions-the-water-vapor-feedback-2/) is a 2008 piece in the Yale Climate Connections series saying more or less what I've said above, but in more detail and without the cake analogy. * ["Water vapour: feedback or forcing?"](http://www.realclimate.org/index.php/archives/2005/04/water-vapour-feedback-or-forcing/) is a great 2005 essay by Gavin Schmidt explaining the role of water vapour in climate change. * ["Explaining how the water vapor greenhouse effect works"](https://www.skepticalscience.com/water-vapor-greenhouse-gas.htm) is a brief Skeptical Science piece mainly focusing on the positive feedback effect. [1]: http://i.stack.imgur.com/LSh2S.jpg