An important detail in the global warming story is that when climate models are run far into the future, increasing CO2 doesn’t do much warming. What supposedly raises air temperature instead is a secondary mechanism, the water vapour feedback from what limited warming CO2 is expected to cause. The idea is that the limited CO2-induced warming in question allows the air to hold more water vapour, and as H2O is a far more powerful greenhouse gas than CO2, the theory goes, the initial warming gets amplified from all the extra water vapour evaporating off the oceans. Except the latest data show the amount of water evaporating off the oceans is going down, not up. Dang. Climate just won’t obey the computers… again.
The study, published in Geophysical Research Letters, is called “Recent Decline in Global Ocean Evaporation Due To Wind Stilling.” As the title suggests there are two things going on in the data: less evaporation and less wind. Is that what the climate models predict? If not, give them a few minutes to fiddle the dials and they’ll make one give you less evaporation and less wind as a tell-tale sign of climate change. Of course then the problem will be that for the decades leading up to 2007 ocean evaporation was rising, which we were told was a tell-tale sign of climate change. Here’s the chart of historical evaporation readings:
From 1988 to 2007 the climate did what it was told and more water evaporated from the ocean surface just as the models predicted. But after that the trend reversed. Oddly, the sea surface continued to warm yet less water vapour was forced into the atmosphere.
The authors note that data also show that the wind got more still after 2007 and they theorize that this decrease caused the slowdown in evaporation. So maybe climate change caused the wind to weaken. But if so, then it will continue, which means evaporation will continue to decline instead of going up, which would mean the water vapour feedback effect isn’t as simple as modelers thought. Once again, climate is complicated and the models are rubbish.
I remember a passage from a decades old NOAA(?) style manual that cautioned, "Do not use the term "positive feedback", say instead "amplifies the negative effects of warming".
About the same time from climatekids.nasa.gov, teacher's advice for the youngsters to tell them that CO2 is an "odourless, invisible gas that comes from dead animals and rotting vegetables", lest they connect it with the bubbles in their soda.
Along with the ultimate PR masterstroke... dirty, black dangerous, "carbon" for CO2, and the universal labelling of white H2O vapor rising from cooling towers, artfully backlit or photoshopped to appear dark, preferably with a dark and stormy sky, as "carbon pollution" always "spewing", the damage to reason, curiosity and scientific literacy is incalculable.
From the study's plain language summary "These results offer a deeper understanding of the complex ways climate change is reshaping the planet's water cycle." I wonder how many of the "settled science" climate models incorporate this "wind stilling" into their code?
Less wind ("stilling") => less evaporation => less water vapour in the atmosphere => less green house effect => cooling????
That article contains a few inaccuracies and misrepresents the scientific understanding of climate change and climate models. Here's a breakdown:
* "The models don't say CO2 will cause much warming." This is false. Climate models consistently show that increased concentrations of CO2 directly lead to a significant increase in global temperatures. This is due to the well-established greenhouse effect of CO2, which traps outgoing infrared radiation. The amount of warming projected varies depending on future emissions scenarios, but the fundamental link between CO2 and warming is a core finding.
* "Instead, it will cause a little bit that will lead to more moisture in the air..." While it's true that warmer air can hold more moisture (a positive feedback known as the water vapor feedback), this isn't presented by climate scientists as the primary driver of warming. The initial warming caused by increased CO2 is the fundamental forcing.
* "...triggering a runaway 'greenhouse effect'." The term "runaway greenhouse effect" is often used to describe a scenario where warming leads to an unstoppable and extreme increase in temperatures, like what is thought to have happened on Venus. While the water vapor feedback amplifies the initial warming from CO2, climate models do not predict a runaway greenhouse effect on Earth due to current or projected levels of CO2. The feedback mechanisms on Earth are complex and are expected to remain within a range that, while causing significant warming, does not lead to an uncontrolled, Venus-like scenario.
In summary:
* Climate models clearly show that increased CO2 is a primary driver of significant warming.
* The water vapor feedback is an important factor that amplifies the initial warming from CO2, but it's not the sole or primary cause.
* The scientific consensus is that while significant warming is projected, a "runaway greenhouse effect" in the Venusian sense is not expected on Earth due to current or foreseeable increases in CO2.
The statement you provided misrepresents the role of CO2 in climate models and exaggerates the role of the water vapor feedback in a way that is not supported by the scientific literature. It also incorrectly uses the term "runaway greenhouse effect" in the context of current climate projections.
The global average absolute humidity measurements since 1980 are far from accurate enough to reach a conclusion about the water vapor positive feedback theoty. The trends from 1980 to 2000 vs. 2000 to 2020 are different and contradict each other. The use of these data to reach any conclusion is BS, to use a scientific term. The only logical conclusion is there is more global average absolute humidity from a warmer troposphere. How much we don't know. Very likely less than IPCC and the Clausius–Clapeyron relation predict. Not that the exact answer matters: More CO2 and greenhouse global warming are both good news.
https://honestclimatescience.blogspot.com/
Water vapor positive feedback is a theory, not a measurement. There are also two negative feedbacks: Earth emits more upwelling radiation as the surface warms frm any cause: Stefan–Boltzmann law. THAT prevents ocean evaporation does play a crucial role in cooling the Earth's surface by absorbing heat energy and transferring it to the atmosphere, which then releases it as latent heat, ultimately driving weather patterns and regulating global temperatures.
I addition. cea currets tranfer heat frm the tropics toward the poles where the greenhouse effect is weaker ad more heat ca escapr into space. Well known is the AMOC stands for Atlantic Meridional Overturning Circulation, a large system of ocean currents that plays a crucial role in regulating global climate by transporting heat and nutrients, and is a key part of the global ocean conveyor belt.
Climate is much more complex than CO2 and a wild guess about a water vapor positive feedback.
Based on science, I celebrate more CO2 and global warming. CO2 warming is mainly in the coldest six months and mainly near dawn (TMIN). Larger food plants and longer growing seasons from CO2. Fear of CO2 is irrational.