Showing posts with label water vapour. Show all posts
Showing posts with label water vapour. Show all posts

Wednesday, 2 January 2019

Water Vapor is the MAJOR GREENHOUSE GAS


Water vapour as a major greenhouse gas


No automatic alt text available. 
Joe Neubarth, via Facebook

I can tell the WORLD over and over again that Water Vapor is the MAJOR GREENHOUSE GAS. Unfortunately, most of the public has only heard about Carbon Dioxide and can not name the other Greenhouse Gases. The one that is most deadly is Water Vapor because it is 75% of Global Heating. CO2 is about ten percent. CO2 is famous because it upset a beautiful balance in nature that had allowed humans to develop on this planet and create civilizations in the past 10,000 years of the five Billion years this planet has been going around the sun.

Ha! Imagine that! Planet Earth has been here 5 Billion Years and in just the last 10 Thousand years man has set out to destroy it. Makes you wonder if our species is worthy of life?

As we approach 16 C Global Average Surface Temperature (GAST), all HELL is going to break loose. We can clearly see it in all of the Interglacials. What happens in those Abrupt Peaks and Crashes is totally independent of the Milankovich Cycles that do not cause Abrupt Heating and Abrupt Cooling, as those cycles do things gradually over a thousand years or more.

As we know now, the "Cooling Cycle" of the Milankovitch Cycle should have us deep in an Ice Age. Unfortunately, the Greenhouse gases have held off the Global Ice Age Cooling and are now commanding Abrupt Global Heating.

What we have seen happen in the middle of the past four large Interglacials is exactly what we are going to see in the near future for our civilization. A sudden rise and a sudden fall are going to be driven by the effects of a rapid increase in water vapor and cloud cover in the atmosphere.

WE have between ZERO and FOUR PERCENT Water Vapor in our atmosphere right now. The average is about 2 percent. As the planet continues to warm that can go up to above 3% or more for total water vapor in the atmosphere and that addition of water vapor will be sudden and consistent with a sudden heat rise.

ONE DRIVES THE OTHER AND THE OTHER DRIVES THE ONE.

That will kill most of us on the planet from Heat Stroke and Starvation as you can NOT grow crops above 104 degrees Fahrenheit and with the recent warming, most of our farmland is already seeing 104 degrees and higher. Higher temperatures result in crop death. Most of them just lay down in the fields and die.

The oceans are way overheated already and they are warming the atmosphere and as the atmosphere warms it accepts more water vapor that will cause an abrupt heating transient that will take Global Average Surface Temperature (GAST) up to 17 degrees C or 18 degrees C on the chart below. That is just 2 to 3 degrees Celsius warmer than we are right now (15 C GAST) but those first two degrees are going to cause a lot of death.

When the condensing Water Vapor gets too heavy in the atmosphere, cumulus clouds will start to block out the sun and we will have abrupt Global Cooling that will take down to 4 C or 5 C GAST
 

Saturday, 17 November 2018

Cirrus clouds, climate change and geoengineering


What is it about cirrus clouds?


After almost 30 years of looking at climate change I am more than confident that I understand what is happening and roughly where it is taking us - far, far faster than anyone expected.  So much so that I am able to identify where many mainstream scientists are telling us only half the truth about exactly how dire it all is.

The change has become so rapid that I have been able to monitor it almost in real time.  That is what I have been doing over the summer melt period in the Arctic,  along with Margo.

Much of what I have picked up has given me a very troubled heart - partially because the actual data has reinforced just how bad things are. It has also made me realise that there is a lot that we are not being told.

In fact, we are being lied to.

In recent months I have been observing the skies above us and noticing strange phenomena  that in 62 years I have never seen before.

For example this:

However, it is this that has given me source for thought.
This photo was taken in another hemisphere yesterday and looks uncannily like what I have been seeing here in New Zealand.
Except that they have had this for a long time, while this is new in this part of the planet - at least in my eyes.

And then there  is this photo taken above Reno Nevada yesterday by NASA satellite.  What are those thin lines running horizontally across the picture?
 
 

And again, here is a picture from here.

We are seeing a lot of clouds that are wispy cirrus cloud  but also clouds that are running like tramslines across the sky.


 Ask anyone to explain these phenomena and one will oftentimes get the lazy response that "for every degree C rise in temperature we will see 10% more water vapour."

What I get from all this is that there is very little understanding of clouds and their importance.


MIT Study: For Every 1 Degree C Rise In Temperature, Tropical Regions Will See 10 Percent Heavier Rainfall Extremes
***
Just about everything you read about climate change will focus on carbon dioxide as a greenhouse gas and will ignore the whole question of water vapour just as the crucial importance of methane is dismissed.

So it is no accident that most of us know little or nothing about the importance of water vapour and clouds so some of the climate change sceptic researchers are also unfamiliar with this.

According to the author of this article the whole connection between water vapour and clouds is a case of the "cat is out of the bag"


However, water vapour is recognised in climate science as a major player (and has been regarded as such for some time now)



11.17.08

Still from animation showing global distribution of atmospheric water vapor The distribution of atmospheric water vapor, a significant greenhouse gas, varies across the globe. During the summer and fall of 2005, this visualization shows that most vapor collects at tropical latitudes, particularly over south Asia, where monsoon thunderstorms swept the gas some 2 miles above the land.



Water vapor is known to be Earth’s most abundant greenhouse gas, but the extent of its contribution to global warming has been debated. Using recent NASA satellite data, researchers have estimated more precisely than ever the heat-trapping effect of water in the air, validating the role of the gas as a critical component of climate change.



Andrew Dessler and colleagues from Texas A&M University in College Station confirmed that the heat-amplifying effect of water vapor is potent enough to double the climate warming caused by increased levels of carbon dioxide in the atmosphere.

See the Wikipedia article on cirrus clouds HERE

Most people are aware of solar energy management whether as a proposal or as an existing reality.

However, as the following will make clear there are psoposals to use contrails from commercila aircraft (rather than military aircraft that are putatively behind the "chemtrail" phenomenon and the spraying with toxic heavy metals  such as aluminium etc



By Michael Marshall

FEATHERY cirrus clouds are beautiful, but when it comes to climate change, they are the enemy. Found at high-altitude and made of small ice crystals, they trap heat – so more cirrus means a warmer world. Now it seems that, by destroying cirrus, we could reverse all the warming Earth has experienced so far.

In 2009, David Mitchell of the Desert Research Institute in Reno, Nevada, proposed a radical way to stop climate change: get rid of some cirrus. Now Trude Storelvmo of Yale University and colleagues have used a climate model to test the idea.

Storelvmo added powdered bismuth triiodide into the model’s troposphere, the layer of the atmosphere in which these clouds form. Ice crystals grew around these particles and expanded, eventually falling out of the sky, reducing cirrus coverage. Without the particles, the ice crystals remained small and stayed up high for longer.

The technique, done on a global scale, created a powerful cooling effect, enough to counteract the 0.8 °C of warming caused by all the greenhouse gases released by humans (Geophysical Research Letters, DOI: 10.1002/grl.50122).

A powerful cooling effect was created – enough to counteract all the human-induced global warming”

But too much bismuth triiodide made the ice crystals shrink, so cirrus clouds lasted longer. “If you get the concentrations wrong, you could get the opposite of what you want,” says Storelvmo. And, like other schemes for geoengineering, side effects are likely – changes in the jet stream, say.

Different model assumptions give different “safe” amounts of bismuth triiodide, says Tim Lenton of the University of Exeter, UK. “Do we really know the system well enough to be confident of being in the safe zone?” he asks. “You wouldn’t want to touch this until you knew.”

Mitchell says seeding would take 140 tonnes of bismuth triiodide every year, which by itself would cost $19 million.

And then there is this:


"In fact, clouds have about 10 times the impact on climate that man-made greenhouse-gas emissions do, said Brian Toon, a researcher at the University of Colorado at Boulder who wasn't involved in the study. "The largest uncertainty in understanding climate change is understanding clouds, since they are so much more important," he said"



***
It is more than unfortunate that people like the author of the following article are climate change deniers.

Scientists plan to melt cirrus clouds to stop global warming? Re-branded weather modification technology tackles climate change.

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Does this mean that whatever they say should therefore be disregarded?  

To me that would be like rejecting scientific knowledge about abrupt climate change because of what the likes of Michael Mann have to say.

That would clearly be presposterous.

The author of the article does have part of the puzzle and accurately cites the reasearch and makes his own (often fallacious) conclusions. 

The following are some extracts from his article:


After millions of concerned citizens resoundingly denounced the airline industry for clouding their skies, after all the media mockery of the chemtrail community, a stunning admission from the scientific community: if climate engineers melt cirrus clouds we may never need to do Stratospheric Aerosol Injection (SAI), a form of Geoengineering Solar Radiation Management (SRM) to cool the planet. This statement follows Chuck Long’s statement from NOAA’s Earth Systems Research Lab that aircraft are “accidentally geoengineering” the planet with ice haze. With masterfully planned verbal ninjitsu these scientists conflate weather modification and geoengineering, cloud seeding and cloud thinning, and cloud condensation nuclei (CCN, aerosols, or cloud seeds) suddenly become ice-nucleating particles (INP). I will now clear the air on the shady nature of Cirrus Cloud Seeding and help you understand the seriousness of Cirrus Clouds!


Here are some citations:
Contrails formed by aircraft can evolve into cirrus clouds indistinguishable from those formed naturally. These ‘spreading contrails’ may be causing more climate warming today than all the carbon dioxide emitted by aircraft since the start of aviation.” [1]
and
A single aircraft operating in conditions favorable for persistent contrail formation appears to exert a contrail-induced radiative forcing some 5000 times greater than recent estimates of the average persistent contrail radiative forcing from the entire civil aviation fleet.” [2]

These two research papers showed a gaping hole in computer models: aerosols, how they form clouds, and their effects on the climate.
2013 “Aerosol-cloud interactions are one of the main uncertainties in climate research.” [3]

Ulrich Schumman, one of the world’s top researchers on contrail-induced cirrus clouds made this statement in 2010 to the ICAO:
Both aspects (soot and flight routing) offer the potential for aviation to reduce the climate impact of aviation (less soot emissions, LESS WARMING and MORE COOLING CONTRAILS, predictable for OPERATIONAL PLANNING) [5]

His statement piqued my curiosity so I asked Dr. Rangasayi Halthore, the head of the FAA’s Aviation Climate Change Research Initiative (ACCRI), what did Schumman mean?
His response made my jaw hit the floor:
Contrails during day cause cooling because of reflecting of sunlight back into space. During night, they trap infrared heat causing heating. So it is a balance between the two time intervals. We would like to have more CICs (contrail-induced cirrus clouds) during day and none during night FAA Scientist: We Want Clouds By Day, None By Night

So imagine my lack of surprise when I read this, dated July 21, 2017:
If the time and place of seeding is selected with care, the climate effect of cirrus thinning can be enhanced. For that, only the long-wave warming effect of cirrus clouds should be targeted, and their solar effect should be avoided. This can be achieved if seeding is limited to high-latitude winters or to nighttime seeding. [6]
Climate Change and Geoengineering: Artificially Cooling Planet Earth by Thinning Cirrus Clouds

Cirrus clouds frequently form through homogeneous nucleation of liquid aerosol particles such as sulfuric or nitric acid. Alternatively, they can form through heterogeneous nucleation with the help of solid aerosol particles such as desert dust, pollen, or other biological particles, which act as ice-nucleating particles (INPs). The cirrus cloud thinning concept is based on the assumption that most cirrus clouds in the present climate nucleate homogeneously.”

The cooling effect of seeded cirrus clouds has three contributions. First, the cirrus clouds form at lower relative humidities that occur at lower altitudes in the atmosphere (see the figure), where they have a smaller warming effect. Second, because the number concentration of INPs is much lower than that of solution droplets, heterogeneously formed cirrus clouds contain fewer ice crystals. These ice crystals can grow to larger sizes and sediment more readily from cirrus levels, reducing the lifetime and optical thickness of cirrus clouds and hence their warming potential. Third, sedimenting ice crystals remove water vapor, the most important natural greenhouse gas, from the upper troposphere.

If cirrus thinning works, it should be preferred over methods that target changes in solar radiation, such as stratospheric aerosol injections, because cirrus thinning would counteract greenhouse gas warming more directly. Solar radiation management methods cannot simultaneously restore temperature and precipitation at present-day levels but lead to a reduction in global mean precipitation because of the decreased solar radiation at the surface. This adverse effect on precipitation is minimized for cirrus seeding because of the smaller change in solar radiation.”

One problem with cirrus seeding is overseeding, which occurs if too many INPs are injected. In overseeding, the cirrus clouds become optically thicker, leading to warming. … In addition, seeding needs to be avoided in cloud-free regions with high relative humidities where no cirrus clouds form. Here, seeding with INPs could lead to cirrus clouds that cause a warming effect on the climate, same as that from contrails. … Thus, if cirrus seeding is not done carefully, the effect could be additional warming rather than the intended cooling.”

The results from model studies of cirrus thinning suggest that the perfect seeding INPs should be large and that seeding could be geographically or temporally limited. Bismuth triiodide (BiI3) has been suggested as a nontoxic and affordable substance for cirrus seeding; other substances such as mineral dust should work as well[ED NOTE: like David Keith’s aluminum nano-particle idea?

Sounds like SAI at a different altitude to me]
However, further research is needed to investigate which particles would be good seeding agents. It is also important to determine whether these INPs also influence lower-lying clouds, and if so, whether this enhances or dampens the effect of cirrus thinning.

If the time and place of seeding is selected with care, the climate effect of cirrus thinning can be enhanced. For that, only the long-wave warming effect of cirrus clouds should be targeted, and their solar effect should be avoided. This can be achieved if seeding is limited to high-latitude winters or to nighttime seeding. Contrary to solar radiation management methods, cirrus seeding is more effective at high than at low latitudes. A small-scale deployment of cirrus seeding could therefore be envisioned—for instance, in the Arctic to avoid further melting of Arctic sea ice. Governance of such local climate engineering might be easier to achieve than for solar radiation management, especially if substantial climate effects outside the targeted region could be avoided. [6]

References

 

[1] Boucher, O. Atmospheric science: Seeing through contrails, Nature Climate Change 1, 24–25 (2011) doi:10.1038/nclimate1078.http://www.nature.com/nclimate/journal/v1/n1/full/nclimate1078.html
[2] Haywood, J. M., R. P. Allan, J. Bornemann, P. Forster, P. N. Francis, S. Milton, G. Rädel, A. Rap, K. P. Shine, and R. Thorpe (2009), A case study of the radiative forcing of persistent contrails evolving into contrail-induced cirrus, J. Geophys. Res., 114, D24201, doi:10.1029/2009JD012650. – http://onlinelibrary.wiley.com/doi/10.1029/2009JD012650/abstract
[3] Ulrike Lohmann, Miriam Kübbeler, Johannes Hendricks and Bernd Kärcher “Dust ice nuclei effects on cirrus clouds in ECHAM5-HAM” AIP Conf. Proc. 1527, 752 (2013); http://dx.doi.org/10.1063/1.4803380
[4] Svensmark, Henrik, and Eigil Friis-Christensen. “Variation of cosmic ray flux and global cloud coverage—a missing link in solar-climate relationships.” Journal of atmospheric and solar-terrestrial physics 59.11 (1997): 1225-1232.http://www.fakeclimate.com/arquivos/Internacional/HenrikSvensmark/svensmark_96_variations%20of.pdf
http://thecloudmystery.com/The_Cloud_Mystery/Home.html
[5] Ulrich Schumann, German Aerospace Center, Recent research results on the climate impact of contrail cirrus and mitigation options, ICAO Colloquium on Aviation and Climate Change 2010http://www.icao.int/Meetings/EnvironmentalColloquium/Documents/2010-Colloquium/1_Schumann_ContrailMitigation.pdf
[6] Ulrike Lohmann, Blaž Gasparini. “A cirrus cloud climate dial?” Science  21 Jul 2017:
Vol. 357, Issue 6348, pp. 248-249 DOI: 10.1126/science.aan3325
http://science.sciencemag.org/content/357/6348/248

CLIMATE CHANGE AND GEOENGINEERING: ARTIFICIALLY COOLING PLANET EARTH BY THINNING CIRRUS CLOUDS


cirrus clouds
21 July, 2017

As part of the Paris Agreement in 2015, nearly 200 world leaders agreed to curb greenhouse gas emissions and strive to keep temperatures at 1.5 degrees Celsius above pre-industrial levels in order to avoid dangerous and irreversible climate change by the end of the century.


At present, climate scientists regard warming of two degrees above pre-industrial levels as the threshold for global warming. After this point, extreme weather will become more likely—increasing the risks of storms, droughts and a rise in sea levels. Consequences include food and water scarcity, and increased migration as parts of the planet become uninhabitable.

If global emissions continue on their current trajectory, some scientists estimate we will surpass the two-degree limit by 2050. And with Donald Trump poised to pull the U.S. out of the Paris Agreement, the chance of achieving the set target looks even less likely.

Over recent decades, scientists from across the globe have been discussing the potential of geoengineering—the deliberate manipulation of the environment that could, in theory, cool the planet and help stabilize the climate.

There are main two types of geoengineering. The first involves removing carbon dioxide from the atmosphere and storing it. This is already being done on an industrial scale, but it is not effective enough at the moment to cope with the huge levels of emissions. The other type, solar radiation management, is more radical—an attempt to reduce the amount of sunlight absorbed by the planet by reflecting it away.

Many ways of doing this have been proposed. One of the most widely discussed (and riskiest) involves the injection of reflective aerosols into the upper atmosphere. This plan is based on the cooling effect of volcanoes: Sulfur dioxide emitted in an eruption causes the formation of droplets of sulfuric acid. These reflect the sunlight away, creating a cooling effect. But this plan could also go very wrong. The sulfuric acid could strip away the ozone layer, leaving Earth completely exposed to the sun’s radiation.

(There is some evidence that this is happening, Certainly, the much-vaunted recovery is a myth - SMR)

In an article published in the journal Science, Ulrike Lohmann and Blaž Gasparini, from the ETH Zurich, in Switzerland, discuss a variation of this idea: the thinning of cirrus clouds to target the long-wave radiation coming from Earth.

Cirrus clouds are thin and wispy clouds that form at high altitudes and do not reflect much solar radiation back into space, creating a greenhouse effect. The higher the altitude at which they form, the larger the warming effect on the climate. And in a warmer climate, cirrus clouds form at higher altitudes.

So what if we got rid of them? These clouds could be thinned out—leading to a reduction in their warming effect—by seeding them with aerosol particles like sulfuric or nitric acid, which act as “ice nucleating particles” or INPs. If these are injected into the level of the atmosphere where cirrus clouds form, the way they form would be altered, resulting in thinner clouds that have less of a warming effect.

The maximum cirrus seeding potential would be achieved by removing all cirrus clouds,” they write. “If cirrus thinning works, it should be preferred over methods that target changes in solar radiation, such as stratospheric aerosol injections, because cirrus thinning would counteract greenhouse gas warming more directly.”

But Lohmann and Gasparini warn that the plan comes with major drawbacks. It could, they say, lead to even more cirrus clouds being formed, exacerbating global warming in the process.



climate changeThe sun rises over an oil field in California’s Monterey Formation.DAVID MCNEW/GETTY IMAGES
Unintended cirrus formation is especially pronounced if the seeded INPs start to nucleate ice at very low relative humidities.... If cirrus seeding is not done carefully, the effect could be additional warming rather than the intended cooling. If done carefully, the negative radiative effect from cirrus seeding should be stronger in a warmer climate, in which the overall radiative effect of cirrus clouds will be larger.”

Because of the dangers, the scientists say any plan to thin cirrus clouds should be limited to specific times and places, where it would be most effective. 
“Contrary to solar radiation management methods, cirrus seeding is more effective at high than at low latitudes. A small-scale deployment of cirrus seeding could therefore be envisioned—for instance, in the Arctic to avoid further melting of Arctic sea ice,” they say, but the scientists add that there are many questions that need to be answered before cirrus thinning can be further explored.
It is also important to remember that, like solar radiation management, cirrus thinning cannot prevent the CO2 increase in the atmosphere and the resulting ocean acidification,” they conclude. “For the time being, cirrus cloud thinning should be viewed as a thought experiment that is helping to understand cirrus cloud–formation mechanisms.”
****

This is what we are told. It’s all a concept. What if it was already happening?

That is where the controversy begins.

In the absence of real countervailing evidence (other than scorn) and based on my own observations and limited research I would have to conclude that is highly likely that some of these ostensibly projected programs are in fact already in use.

However, most of this lies in the realm of asking questions rather than being dead certain.

Tuesday, 5 July 2016

Water vapour in troposphere as a positive feedback


Keeping an eye on the Arctic and many other things has meant that I have ignored some other very important positive feedbacks

Catastrophic Water Vapor Feedback is Kicking in * 1°C - Warming is as Much as 3°C * Climate Change





See Guy McPherson's list of self-reinforcing positIve feedbacks HERE


Global warming amplifier: Rising water vapor in upper troposphere tointensify climate change



13 August, 2014

A new study from scientists at the University of Miami Rosenstiel School of Marine and Atmospheric Science and colleagues confirms rising levels of water vapor in the upper troposphere -- a key amplifier of global warming -- will intensify climate change impacts over the next decades. The new study is the first to show that increased water vapor concentrations in the atmosphere are a direct result of human activities.

Each 1 Degree C We Warm the Planet adds 7% increase in Moisture


Kevin Hester

For every 1 degree C we increase the temperature on the planet we see 7% more moisture in the atmosphere. We are heading to and beyond the IPCC worst case scenario of  6C minimum which will generate another 40% of moisture in the air. This will lead to a greater number of flooding events and increased number of lightning strikes and Tornadoes.

This is an enormous amount of energy and associated warming as water vapour is in itself a green house gas.
11921707_964981540228183_4406605340541774810_n

The impact of climate change may be worse than previously thought, a new study suggests”:  As world leaders hold climate talks in Paris, research shows that land surface temperatures may rise by an average of almost 8C by 2100, if significant efforts are not made to counteract climate change.”

Personally I disagree with the suggestion that it will take until the magic 2100 for our locked in 8C temperature rise. Factor in the myriad of feedback loops and we could be there in a few decades,not that humans will survive that long to bare witness.

Such a rise would have a devastating impact on life on Earth:  ‘Climate Outlook May be Worse than Feared.’

The amount of water vapor in the atmosphere exists in direct relation to the temperature. If you increase the temperature, more water evaporates and becomes vapor, and vice versa. So when something else causes a temperature increase (such as extra CO2 from fossil fuels), more water evaporates. Then, since water vapor is a green house gas, this additional water vapor causes the temperature to go up even further—a positive feedback.”

How much does water vapor amplify CO2 warming? Studies show that water vapor feed backroughly doubles the amount of warming caused by CO2. So if there is a 1°C change caused byCO2, the water vapor will cause the temperature to go up another 1°C. When other feedbackloops are included, the total warming from a potential 1°C change caused by CO2 is, in reality, as much as 3°C.

A warmer atmosphere can hold more moisture, and globally water vapour increases by 7% for every degree centigrade of warming.”

Excellent article and Q & A from The Guardian below:  ‘How Will Climate Change Affect Rainfall?


Human-caused global warming is causing the upper troposphere to become wetter


We have long suspected that greenhouse gases which cause the Earth to warm would lead to a wetter atmosphere. The latest research published by Eul-Seok Chung, Brian Soden, and colleagues provides new insight into what was thought to be an old problem. In doing so, they experimentally verified what climate models have been predicting. The models got it right… again.

To be clear, this paper does not prove that water vapor is a greenhouse gas. We have known that for years. Nevertheless, the paper make a very nice contribution. The authors show that the long-term increase in water vapor in the upper troposphere cannot have resulted from natural causes – it is clearly human caused. This conclusion is stated in the abstract,

Our analysis demonstrates that the upper-tropospheric moistening observed over the period 1979–2005 cannot be explained by natural causes and results principally from an anthropogenic warming of the climate. By attributing the observed increase directly to human activities, this study verifies the presence of the largest known feedback mechanism for amplifying anthropogenic climate change.

As stated earlier, climate models have predicted this moistening – before observations were available. In fact, the models predicted that the upper troposphere would moisten more than the lower atmospheric layers. As the authors state,

Given the importance of upper-tropospheric water vapor, a direct verification of its feedback is critical to establishing the credibility of model projections of anthropogenic climate change.

To complete the experiments, the authors used satellite measurements of radiant heat. The emissions have changed but it wasn’t clear why they have changed. Changes could be caused by increases in temperature or from increased water vapor. To separate the potential effects, the authors compared the first set of experiments with others made at a different wavelength. That comparison provided a direct measure of the separate effect of moistening.

Next, the authors used the world’s best climate models to test whether the observed trends could be caused by natural changes in the Earth’s climate or whether they require a human influence. Sure enough, only the calculations that included human-emitted greenhouse gases matched the observations. The authors conclude that,

Concerning the satellite-derived moistening trend in recent decades, the relations of trend and associated range among three experiments lead to the conclusion that an increase in anthropogenic greenhouse gases is the main cause of increased moistening in the upper troposphere.

The authors then went further by showing that their computed results encompass third-party measurements only when the impacts of human-emitted greenhouse gases are included.

I chuckled when I asked Dr. Andrew Dessler about this study, and he told me,

Because of water vapor’s importance as a greenhouse gas, the water vapor feedback occupies a central role in the climate system. Over the years, our understanding of this process has increased steadily, and this paper is a very useful contribution. It nicely demonstrates that the observations of upper tropospheric moistening are unlikely to have arisen without the increase in carbon dioxide from human activities. At this point, I think it would be fair to say, “stick a fork in it, the water vapor feedback’s done.”

So once again, observations have confirmed the models and the scientists can check another item off their “to do” box.