A new study published in Science reveals that the fertilizing effect of excess CO2 on vegetation is decreasing worldwide
SPANISH NATIONAL RESEARCH COUNCIL (CSIC)
When plants absorb this gas to grow, they remove it from the atmosphere and it is sequestered in their branches, trunk or roots. An article published today in Science shows that this fertilizing effect of CO2 is decreasing worldwide, according to the text co-directed by Professor Josep Peñuelas of the CSIC at CREAF and Professor Yongguan Zhang of the University of Nanjin, with the participation of CREAF researchers Jordi Sardans and Marcos Fernández. The study, carried out by an international team, concludes that the reduction has reached 50% progressively since 1982 due basically to two key factors: the availability of water and nutrients. “There is no mystery about the formula, plants need CO2, water and nutrients in order to grow. However much the CO2 increases, if the nutrients and water do not increase in parallel, the plants will not be able to take advantage of the increase in this gas”, explains Professor Josep Peñuelas. In fact, three years ago Prof. Peñuelas already warned in an article in Nature Ecology and Evolution that the fertilising effect of CO2 would not last forever, that plants cannot grow indefinitely, because there are other factors that limit them.
If the fertilizing capacity of CO2 decreases, there will be strong consequences on the carbon cycle and therefore on the climate. Forests have received a veritable CO2 bonus for decades, which has allowed them to sequester tons of carbon dioxide that enabled them to do more photosynthesis and grow more. In fact, this increased sequestration has managed to reduce the CO2 accumulated in the air, but now it is over. “These unprecedented results indicate that the absorption of carbon by vegetation is beginning to become saturated. This has very important climate implications that must be taken into account in possible climate change mitigation strategies and policies at the global level. Nature’s capacity to sequester carbon is decreasing and with it society’s dependence on future strategies to curb greenhouse gas emissions is increasing”, warns Josep Peñuelas.
The study published in Science has been carried out using satellite, atmospheric, ecosystem and modelling information. It highlights the use of sensors that use near-infrared and fluorescence and are thus capable of measuring vegetation growth activity.
Less water and nutrients
According to the results, the lack of water and nutrients are the two factors that reduce the capacity of CO2 to improve plant growth. To reach this conclusion, the team based itself on data obtained from hundreds of forests studied over the last 40 years. “These data show that concentrations of essential nutrients in the leaves, such as nitrogen and phosphorus, have also progressively decreased since 1990,” explains researcher Songhan Wang, the first author of the article.
The team has also found that water availability and temporal changes in water supply play a significant role in this phenomenon. “We have found that plants slow down their growth, not only in times of drought, but also when there are changes in the seasonality of rainfall, which is increasingly happening with climate change,” explains researcher Yongguan Zhang.
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Reference article:
Wang S, Zhang YG, Ju W, Chen, J, Ciais P, Cescatti A, Sardans J, Janssens IA, Sardans, J, Fernández-Martínez, M, … Penuelas J (2020). Recent global decline of CO2 fertilization effects on vegetation photosynthesis. Science, DOI: 10.1126/science.abb7772
Photosynthetic plants absorb CO2 from the air through openings (stomata) in their leaves, which also allow some water vapor to leak out (transpiration). Scientific studies on individual plants have shown that increasing the CO2 concentration in the air enables the plants to reduce the area of their stomata, thereby reducing water loss. Although the photosynthesis reaction does consume water, most plants absorb much more water through their roots than is consumed by reaction, due to other plant functions that use water as a solvent.
Assuming that the water supply in the soil does not depend on atmospheric CO2, increasing CO2 concentration would decrease the water loss rate, and enable the plant to survive on less water during a drought, due to the reduced water loss through the stomata.
The greening is causing much of the warming. If the greening stops the (extra) warming will also stop.
eh?
Please explain that with some relevant numbers
The lessening of greening argument apparently rests on supposed water and nutrient contraints.
The water constraint is spurious for two reasons. Most places are not water constrained, period. Those that are, like the Sahel, experience MORE greening because with more CO2 C3 plants need less water because they lose less via their stomata.
The nutrient constraint is also spurious for two reasons.
1. All nutrients in natural forests and ‘wild’ prairie vegetation get fully recycled via decay, even in severely leached out soils like the Amazon rain forest. More greening means more decay recycling on decadal scales. Otherwise there would be no Amazon rain forest.
2. In most soils, all nutrients except nitrogen are also continuously (albeit slowly) increased by subsoil ‘rock’ weathering (admittedly intensive ag requires supplemental fertilizer), and nitrogen is continuously added by nitrogen fixing bacteria colonizing roots. More CO2 means slightly more acidic rain, so slightly accelerated subsoil weathering.
Last time I checked the satellite greening data (late 2014), it was up 17% during the satellite era (start circa 1982) and accelerating, not decelerating. Just went and checked a few sat greening papers from 2016-2019. No mention of decelerating greening anywhere, let alone by half.
So, here is how it really works in arid areas. The greening starts as a fringing growth. This provides some shade, some cooling and new seeding for a new fringing growth added on. …. It expands the change in local climate. In the rainy season, say in the Sahel south of the Sahara, this new growth retains more and more of the soil moisture that otherwise would run off rapidly. Creatures, large and small take up residence and contribute available nitrogen as does burgeoning growth of microbial action. Ecologies know how to do this.
Oh, and the new vegetation takes up its full share of the CO2 while the original “fringe” (when it’s mature) will take up less. So the 40yrs of greening weve had will be repeated anew again and again plus adding on 50% for last 40yrs…. and down to a small percentage eventually. Linear minds have problems imagining a dynamic picture where, despite a declining effect on mature existing growth, the whole system is exponential in growth as is, ergo, demand for CO2 until coverage is complete (centuries hence).
Also, devegetated arid areas got that way from diminishing water availability, not from disappearance of nutrients. That is why greening can occur with only an increase in CO2 in warm parts of the globe. Revegetation itself will also change the climate itself!
Biologists seem to see ecology as a fixed thing, a painting. If there is change, something bad has happened. This is why most gloom and doom forecasts seem to come from biologists and all turn out to be diametrucally wrong. Bios, take a couple of paleontology and historical geology courses for remedial purposes.
Does anyone know of studies where Greenhouses have had their CO2 increased from 400ppm to 1200ppm, does it affect the temperature in the greenhouse and by how much?
I ask this question after reading on No Tricks Zone about naturally occurring very high levels of CO2 not affecting the temperature upwards, but downwards.
Link here.
https://notrickszone.com/2020/12/10/real-world-outdoor-experiment-as-co2-naturally-rises-from-1-to-75-surface-temperatures-drop-10c/
Wow! Those spiders transiting 100% CO2 air can hold their breath for a long time.
Gaia says, “I have not yet begun to green.”
The greenies don’t know what GREEN is…
… or what causes it. 😉
ANYONE that thinks we should limit CO2 emissions is either BRAIN-DEAD…
…… or the gullible PATSY of the socialist anti-capitalist anti-LIFE agenda.
Unfortunately, there are a LOT of people like that.
In a warming world, longer growing seasons in colderclimates. Not to mention since they say the artic is melting all that area to grow also absorbing more CO2!
sorry, just too incoherent to read. !
We haven’t heard about any increases in the phytoplankton, especially near the polar regions, due to increased CO2 dissolved in the oceans. Should be “greening” the oceans considerably, and therefore increasing ocean life. Any thoughts?
There has been quite a bit written about the large increase of microscopic ocean plants.
Wow! These modeling expert scientists have rediscovered Liebig’s Law. What an accomplishment!
https://en.wikipedia.org/wiki/Liebig's_law_of_the_minimum
Liebig law of the minimum, often simply called Liebig’s law or the law of the minimum, is a principle developed in agricultural science by Carl Sprengel (1840) and later popularized by Justus von Liebig. It states that growth is dictated not by total resources available, but by the scarcest resource (limiting factor). The law has also been applied to biological populations and ecosystem models for factors such as sunlight or mineral nutrients.
And parenthetically, reading these comments is a celebration of well-deserved snarky invective, for yet another ignorant half-assed “politicized-science” publication that is really an embarrassment for the “scientists” and the journal. As is often the case here at WUWT, the comments are as or more enlightening than the original papers or articles. Kudos to us all. Now all we need is a global media empire to get the word out.
““We have found that plants slow down their growth, not only in times of drought, but also when there are changes in the seasonality of rainfall, which is increasingly happening with climate change,” explains researcher Yongguan Zhang.”
So, they finally agree that tree ring growth cannot be used as a proxy for temperature! Well this is progress at least.
Meanwhile, let me see if I can summarize this…It’s worse than we thought?
The real question in that quote is: since “change” is the default condition of all climates, either gradual or rapid, depending on the location; how can a continuous condition be occurring “increasingly”?
Is there any evidence for these claimed changes in the “seasonality of rainfall”? Changes can mean a decrease or increase. Last I read, climate change can cause both droughts and floods. So which is it? Over what time period? If it is just over a few years, it is just noise on a graph of natural variability. It has to be long term to mean anything. And are these changes “increasingly happening”? That would mean the changes in the seasonality of rainfall (whatever that means) are accelerating. Is there any evidence for that? Or are these researchers just blowing CO2 laden smoke in an attempt to make themselves relevant?
“In fact, this increased sequestration has managed to reduce the CO2 accumulated in the air, but now it is over. “
Over? Was it over when the Germans bombed Pearl Harbor?
“Over? Was it over when the Germans bombed Pearl Harbor?”
???
So many things in this make no sense. Sure, if there are not enough nutrients and water available, all the CO2 in the whole world won’t matter. Farmers who harvest crops know this and replace those nutrients when needed. Food won’t be greatly affected. My lawn, sure, a little slower growing won’t be all bad.
Water comes from the roots. More CO2 means closed stomata and less water loss, so less water is needed.
This all sounds like a fiction story and made up data to support it. Typical pseudoscience.
Greenhouses pump CO2 in at a level of 1000 PPM as a result of testing what is optimum for crop growth. And we are a long way from that yet.
Greenhouses also commonly turn of their CO2 supplementation about 2-3 hours before dark. This is because it (lowering CO2) allows the plants to do less “dark respiration” (where oxygen that during day the plant puts out doing photosynthesis stops at night & oxygen is then used forming CO2 that gets put out).
The benefit of reduced night CO2 output by a plant is that less assimilated carbon (from daytime photosynthesis) is put back out of the plant. In other words, the CO2 fed into greenhouse operations has a day/night cycle in order to get greater growth.
Commentators frequently report about greenhouse productivity from added CO2 & overlook the difference to elevated ambient CO2. In the outside world it needs to born in mind any CO2 ppm being referred to isn’t dialed down at night (unless research project design does so).
The major sequestering of CO2 and greening of the planet occurs in the cold ocean waters around the poles. There is plenty of water and plenty of nutrients for phytoplankton to feed on. Increasing this bottom of the food chain results in more food for a growing human population.
The paper says:
I’m gonna call BS on that … they claim that CO2 sequestration has been decreasing because of the claimed decrease in CO2 fertilization of plants. But there’s an easy way to calculate sequestration. The relationship between emitted carbon (GTonnes C) and airborne CO2 is that 2.13 Gtonne of emitted C creates 1 ppmv of airborne CO2.
However, the amount of airborne CO2 is never as much as the amount emitted, because of sequestration … which means that we can calculate the sequestration. And here it is, from 1959 to 2019:
As you can see, there’s been no significant decrease in the sequestration, from trees or anything else.
w.
w – Neat. Thx.
Nifty. Thx!
Gosh willikers, Thx
I agree. I get roughly the same result, as you can see in this graph (generated using 10-year smoothing):
http://sealevel.info/global.1751_2014_2019.ems5_v07c_files/image002.png
In fact, as you can see from the linear regression trend line, the percentage of anthropogenic CO2 emissions sequestered by biosphere and oceans has been increasing slightly (i.e., the “airborne fraction” has been trending down):
http://sealevel.info/global.1751_2014_2019.ems5_v07c.html
Here’s the spreadsheet which generated it:
http://sealevel.info/global.1751_2014_2019.ems5_v07c.xlsx
This is the same thing spreadsheet, exported to HTML:
http://sealevel.info/global.1751_2014_2019.ems5_v07c.html
Currently, the net removal/sequestration rate of CO2 from the atmosphere is about half the anthropogenic CO2 emission rate, and this 2016 paper reports that it is increasing:
https://www.nature.com/articles/ncomms13428
Willis: right on! The progression of greening from the periphery of arid regions occurs in fringes inwards. The new fringes have no ‘memory’ of the previous fringes, so they develop with the full capacity of CO2 sequestration added on to the lesser sequestration of the older fringes. It could go on for centuries if cooling doesn’t stop it.
Also, if warming of the oceans coming out of the LIA increases CO2 evolution, it would tend to drive a somewhat exponential sequestration in the arid regions if the mechanism I describe is roughly correct. Of course pre-existing vegetation is ‘fattening’ and the modest warming is driving vegetation growth and expansion in the sub-arctic. The greening has just begun.
The Sahara was green as late as about 5,500 BC, which is around when the people inhabiting Nabta Playa in the Egyptian Western Desert were forced to move to the Nile Valley.
The paleodata suggests cold periods such as DO Events lead to drought in the Middle East. Warmer periods appear correlated with more rainfall. So if the climateers are right that CO2 causes warming then you expect there’s a lot of greening to go yet, as rainfall increases across the Sahara.
Sea level rise is a horrible problem – beyond the ken of mankind! Just compare a map of modern Boston to a map of colonial Boston like I’m doing, and you will see how much area in and around that poor city has been lost to the rising sea in just a couple centuries.
Oh wait… I mixed up the maps… never mind!
Incoherent cut/paste garbage !!
The guy you’re responding to is clearly mentally disturbed … judging by the spamming with the same C&P of meaningless “hashtags”, three times in one thread.
Yet the fraction of CO2 in the atmosphere above 280 ppm being removed by plants and the ocean remains constant. That discredits the study”s conclusion that CO2 removal by greening is becoming saturated. It’s sad that a study gets published when it can be falsified so easily.
They are working on that.
If it works as planned, falsifying reports will become much harder. It may even be banned altogether.
“A new study published in Science reveals that the fertilizing effect of excess CO2 on vegetation is decreasing worldwide.”
The growth rate of CO2 has been about 2.5 ppm per year for last 10 years and during this time China has had surpassed the world in CO2 emission. And we need another country to increase it’s CO2 emission like China did in order to increase fertilizing effect.
And don’t have a country that can burn as much coal and pollute the world like China did.
It seems the biggest way to increase the greening of the World is by adding lots of water to Sahara Desert.
Perhaps new peace deal with Morocco and Israel will lead to greening of Sahara desert.
And it seems to me it possible that with greening of desert, this could lead to less hurricanes in the Atlantic ocean- though perhaps significantly less fertilization to Brazil.
Studies such as this probe the limits of human dishonesty.
Those limits are impressively wide, a horizon at apparently infinite distance.
But they are being probed none the less.
Although it’s evil, one can’t but feel a sense of awe.
You can’t not admire them: they have been really creative in finding reasons why increasing CO2 fertilisation is still bad.
You can’t stop Greenie Downer!
I find the topic of spontaneous nonlinear pattern formation to be irresistably compelling.
The region of Hopf bifurcation at the initial onset of chaos is the interesting part of chaos where pattern formation arises. By contrast full-blown chaos and high dimensional turbulence are not so fecund of form and pattern.
One of the most amusing aspects of chaos is watch the contortions that people perform to try to hide themselves from the existence of chaos and related phenomena, fearing (rightly) that it will burst the bubble of all their pet theories in La La Linearland that exists in computer models but almost nowhere on earth.
One of the places where emergent pattern is visible is the edge of desert. This is the edge of where plant life can exist, the boundary between life and death. Here you get the predictable emergence of Turing patterns with grasses spontaneously forming clumps as in these images.
https://images.app.goo.gl/FCqs6q47ddGAh6C48
https://images.app.goo.gl/fFChYtsjb5PMTJtT8
https://images.app.goo.gl/pqh47mdS7cxvmPRL6
CO2 of course will affect where this boundary lies. Already Saharan regions of previous desert are greening over, much to the enragement of the Khmer Vert. Deserts turn to grasslands and grasslands to forest.
Your reaction to the greening desert from CO2 increase says what kind of a human being you are.
Either you love it or you hate it.
The claim is that terrestrial land sinks will gradually fill as trees lose their capacity to draw more from fertilization from soils and moisture from the air. Amazon rainforests stand in opposition to these claims don’t they? At 55 million years old and counting they generate their own clouds and moisture (hence their name), and have managed to persevere in the face of nutrient-poor soils. Natural forces tend to replace what is lost.
This latest “science” from the AGW-ers is good news. Their weak claim is clear acknowledgment that the greening of the Earth is occuring and its effects are universally beneficial.