Guest essay by Eric Worrall
According to a new study, increased transpiration from CO2 engorged plants will return more water vapour to the atmosphere, reducing runoff available to fill reservoirs.
Mid-latitude freshwater availability reduced by projected vegetation responses to climate change
Justin S. Mankin, Richard Seager, Jason E. Smerdon, Benjamin I. Cook & A. Park Williams
Abstract
Read more: https://www.nature.com/articles/s41561-019-0480-x
Plants are expected to generate more global-scale runoff under increasing atmospheric carbon dioxide concentrations through their influence on surface resistance to evapotranspiration. Recent studies using Earth System Models from phase 5 of the Coupled Model Intercomparison Project ostensibly reaffirm this result, further suggesting that plants will ameliorate the dire reductions in water availability projected by other studies that use aridity metrics. Here we complicate this narrative by analysing the change in precipitation partitioning to plants, runoff and storage in multiple Earth system models under both high carbon dioxide concentrations and warming. We show that projected plant responses directly reduce future runoff across vast swaths of North America, Europe and Asia because bulk canopy water demands increase with additional vegetation growth and longer and warmer growing seasons. These runoff declines occur despite increased surface resistance to evapotranspiration and vegetation total water use efficiency, even in regions with increasing or unchanging precipitation. We demonstrate that constraining the large uncertainty in the multimodel ensemble with regional-scale observations of evapotranspiration partitioning strengthens these results. We conclude that terrestrial vegetation plays a large and unresolved role in shaping future regional freshwater availability, one that will not ubiquitously ameliorate future warming-driven surface drying.
Sadly the full study is paywalled, but I think we get the idea; Plants are bad. The study suggests anything which increases transpiration, like anthropogenic CO2 emissions or presumably other changes which lead to increased transpiration, like planting trees, increases stress on the global supply of fresh water.
Of course, there are a few contradictory studies which suggest rainfall decreases if trees are cleared, studies which suggest plant transpiration plays an important positive role in the water cycle, but these studies are based on observations rather than climate projections.
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From the abstract
“….ostensibly reaffirm this result,…..We demonstrate that constraining the large uncertainty in the multimodel ensemble with regional-scale observations of evapotranspiration partitioning strengthens these results.”
ostensibly– 1. in an ostensible manner. 2. to all outward appearances.
constrain– 1a. to force by imposed stricture, restriction, or limitation.
I don’t think we have to read the paper or understand much botany. Do these modelers ever go out in the field, or check their grammatical construction? Or even their science? I just ran across a paper with a new (to me) acronym–HARKING=Hypothesis after Results Known.
Then build bigger reservoirs to store more water. Simples…
.
““We show that projected plant responses directly reduce future runoff across vast swaths of North America, Europe and Asia because bulk canopy water demands increase with additional vegetation growth and longer and warmer growing seasons.”
They needed a study to learn this? They could have just asked a farmer or a forester but, that would have meant they didn’t get funding for their study so…
Never mind, the experts have a new solution.
11,000 Experts Propose Final Solution To Global Warming: Just Kill Billions Of People
https://www.zerohedge.com/health/11000-experts-make-modest-proposal-end-global-warming-just-kill-billions-people
In response to a comment on another website (Jo’s) I pointed out to the poster that when we burn any of the various fossil fuels (coal excepted), about half of what comes out of back end of the ICE is water vapor. The US alone, using 17 – 18 million bopd (equivalent), is putting that much “juvenile” water vapor into the atmosphere each day. After a half-century, or longer, I cannot see that this is a trivial amount.
And, as was pointed out, in a warming world, there is more oceanic evaporation, putting even more water vapor into the atmosphere, so color me skeptical of this ‘study’ and its conclusions.
Regards to all,
Vlad
Compared to the amount of water vapor in the atmosphere at any given time, I think it probably is a trivial amount.
This study must qualify for one of the worst ever written by peope that call them selves scientists .
The whole global warming scam relys on INCREASED water vapour and then positive feed back to cause more warming .
A warmer atmosphere does carry more water and any vegetation will reduce runoff over land with no vegetation .Most of the water in the atmosphere is evaporated from the surfave of the oceans and the clouds move over land masses and drop the moisture as rain hail or snow .
Very little moisture is absorbed from land masses compared with the oceans and lakes .
A little more water vapour in the atmosphere over land will usally fall over land .
A news headline here this morning is that 11,000 scientists have signed a climate emergency .
If this article represents the present crop of scientists that says it all.
I have been farming for over 60 tears and have followed closely this global warming scam since it was hatched but this study is the worst I have seen.
Graham
Proud to be a farmer feeding the world
Rain Forest? Anyone? Anyone? Rain Forest?
the leftist AGW/CC nut jobs just won’t be satisfied or happy unless the world is coming to an end, one way or another
Is this the start of an anti-plant propaganda campaign? By “green” activists?
Always on our dime:
We thank the Earth System Grid Federation and their archiving of the Coupled Model Intercomparison J.S.M. was funded by the Burke Research Initiation Award and the National Science Foundation award AGS‐1243204, which also supported R.S. and J.E.S. Additional support for R.S. and J.E.S. was provided by National Science Foundation awards GS‐1401400, AGS‐1805490, AGS-1602581 and OISE-1743738. B.I.C. was supported by the NASA Modeling, Analysis, and Prediction. A.P.W. was supported by National Science Foundation award AGS-1703029 and NASA award 16-MAP16-0081. Lamont contribution #8359.
If more plant life increases water retention won’t that reduce sea level rise?
(Next report: “Oh noes! Reduced rate of SLR will stunt vertical coral growth rates.”
If trees are cleared, the first thing that happens is massive increases in topsoil erosion. In many areas with tropical rainfall levels, we have already seen that happen due to commercial logging.
What about deserts? You think that they are great suppliers of rainwater across the Sahara? I beg to differ.
Tropical forests create their own weather leading to daily rainstorms in late afternoon.
These studies are just agenda-driven, looking for any angle of scaremongering to justify ‘further research’.
The other interested parties will be indoor growing factories creating synthetic environments: the more of those they want to build, the less therest of the world must be able to provide. Traditional agriculture is bad, we must solely grow using hydroponics, aquaponics and aeroponics!
Expect the BBC to be plugging this: they are shameless propagandists utterly without moral compass.
Having gone to the article abstract and looked at the data source statement, I can now safely say this study is 100% model porn. There is no real data to be found anywhere in the article. The only good thing I can say about it is “no plants were harmed in the production of this fantasy.”
+20
Thanks
So, for this climate clown, more CO2 will cause more water depletion, but according to another clown :
“By hoarding water underground, vegetation will help saturate soil, boosting rain runoff”
https://wattsupwiththat.com/2019/10/24/plant-physiology-will-be-major-contributor-to-future-river-flooding/
The union of circus clowns should sue these pseudo-scientists for unfair competition.
Frogs getting bigger, frogs getting smaller, more earthquakes, fewer earthquakes, bees dying, landslides increasing, landslides decreasing.
( not hyperbole, but all part of the shameful peer review treasure)
And these are the ” scientists” that just no CO2 will kill us all.
So one can conclude that wild fires that reduce vegetation are good and should be encouraged. The turning of wilderness into urban areas is also good because if greatly lessens the amount of pesky plants per acre. Cancer causing herbicides are actually good for the earth and should be applied to all public lands to kill all vegetation on them. Cancer causing chemicals tend to reduce human population which is also good for the Earth.
Other than having the higher CO2/transpiration relationship backwards, they are doing great. Simply amazing, and to think someone has spent good money on this study.
+10
“… these studies are based on observations rather than climate projections.“
Let’s tell it like it is, Eric.
“These studies are based on facts rather than guesswork.” And even that’s more polite than they deserve.
For readers with a strong stomach — and low blood pressure: https://www.bbc.com/news/science-environment-50302392
The forgot to mention that Saint Greta was coauthor to the fantasy.
Mount Kilimanjaro, Amazon Rain Forest.
Need more be said?
Let me guess…. their findings are from models and they’ve parameterized a lot of complicated things like how different soils absorb rainfall and how additional water vapor in the air transpired by plants might add rainfall to other places.
Can these people seriously be called scientists?
This is monumentally silly. All water lost by evapotranspiration comes back down as rain/snow. The water doesn’t disappear or sray permanently in the atmosphere. This is seen e. g. in the Amazon which is unique since it has very heavy preciptation in a lowland area far from any sea. This is ordinarily impossible, but happens here because it is the same water that is evaporated from the forest in the morning that comes down as rain in the afternoon, again and again and again.
Increased plant growth however can consume water through photosynthesis, which forms plant tissue from water plus carbon dioxide, but this is only temporary. Sooner or later the plant tissue burns, rots or is eaten and the water (and CO2) returned to circulation.
Clearly the science is not settled and justifies funding the investigators’ lavish lifestyles and retirements so that they can complete phase 25 of the Coupled Model Intercomparison Project. I would suggest Congress should create a new Cabinet department to oversee the work.
At least they’ve admitted that CO2 is good for plants, much of which is something called “food”.
Long before Man thinks he invented “recycling”, nature has been at it.
Water is a prime example.
Gunga Din: “At least they’ve admitted that CO2 is good for plants…”
Yes, good point, except that these plants are in the wrong place at the wrong time… and the growth is unprecedented, unnatural and man made. Therefore these plants are bad.
I don’t need the sarc/ but just in case 🙂
The sarc/ is needed. You sounded like you had contacted virulent CO2 Derangement Syndrome.
Rex Tasha: “The sarc/ is needed. You sounded like you had contacted virulent CO2 Derangement Syndrome.”
Well, no one can fault me for being able to know what the Left believes. That’s the first step in being able to change minds… understanding their fatally flawed thinking.
These research guys just want to push the CAGW party line.
Plants eat CO2. CO2 is good for life.
It is an observational fact that the recent increase in atmospheric CO2 has caused a massive expansion of plant growth in arid places.
Increased CO2 causes plant’s biomachinery to change (the plant reduces the number of stomata on their leaves and other biochemical changes) which significant reduces the plant’s water loss in arid locations which enable plants to live with less water.
The plants must decide which they need more:
1) water or 2) carbon dioxide.
http://www.sciencedaily.com/releases/2003/05/030509084556.htm
Greenhouse Gas Might Green Up The Desert; Weizmann Institute Study Suggests That Rising Carbon Dioxide Levels Might Cause Forests To Spread Into Dry Environments
The Weizmann team found, to its surprise, that the Yatir forest is a substantial “sink” (CO2-absorbing site): its absorbing efficiency is similar to that of many of its counterparts in more fertile lands. These results were unexpected since forests in dry regions are considered to develop very slowly, if at all, and thus are not expected to soak up much carbon dioxide (the more rapidly the forest develops the more carbon dioxide it needs, since carbon dioxide drives the production of sugars). However, the Yatir forest is growing at a relatively quick pace, and is even expanding further into the desert.
Plants need carbon dioxide for photosynthesis, which leads to the production of sugars. But to obtain it, they must open pores in their leaves and consequently lose large quantities of water to evaporation. The plant must decide which it needs more: water or carbon dioxide. Yakir suggests that the 30 percent increase of atmospheric carbon dioxide since the start of the industrial revolution eases the plant’s dilemma. Under such conditions, the plant doesn’t have to fully open the pores for carbon dioxide to seep in – a relatively small opening is sufficient. Consequently, less water escapes the plant’s pores. This efficient water preservation technique keeps moisture in the ground, allowing forests to grow in areas that previously were too dry.
http://news.nationalgeographic.com/news/2009/07/090731-green-sahara.html
The green shoots of recovery are showing up on satellite images of regions including the Sahel, a semi-desert zone bordering the Sahara to the south that stretches some 2,400 miles (3,860 kilometers).
Images taken between 1982 and 2002 revealed extensive regreening throughout the Sahel, according to a new study in the journal Biogeosciences.
The study suggests huge increases in vegetation in areas including central Chad and western Sudan.
In the eastern Sahara area of southwestern Egypt and northern Sudan, new trees—such as acacias—are flourishing, according to Stefan Kröpelin, a climate scientist at the University of Cologne’s Africa Research Unit in Germany.
“Shrubs are coming up and growing into big shrubs. This is completely different from having a bit more tiny grass,” said Kröpelin, who has studied the region for two decades
In 2008 Kröpelin—not involved in the new satellite research—visited Western Sahara, a disputed territory controlled by Morocco.
“The nomads there told me there was never as much rainfall as in the past few years,” Kröpelin said. “They have never seen so much grazing land.”
“Before, there was not a single scorpion, not a single blade of grass,” he said.
“Now you have people grazing their camels in areas which may not have been used for hundreds or even thousands of years. You see birds, ostriches, gazelles coming back, even sorts of amphibians coming back,” he said.
“The trend has continued for more than 20 years. It is indisputable.”
http://www.springerlink.com/content/w7gy1cyyr5yey994/
Carbon dioxide effects on stomatal responses to the environment and water use by crops under field conditions
, with a doubling of [CO2] reducing mean midday conductances by 50% in others. Elevated [CO2] increases leaf area index throughout the growing season in some species. Simulations, and measurements in free air carbon dioxide enrichment systems both indicate that the relatively large reductions in stomatal conductance in crops would translate into reductions of <10% in evapotranspiration, partly because of increases in temperature and decreases in humidity in the air around crop leaves.
The guy falling the tree is incompetent.
Allegorical regarding the content of this computer model paper?