July 24, 2017 5.18am EDT
Tropical rainforests are among the biggest contributors to the global greening boom. AAP Image/Dave Hunt
Rising carbon dioxide is making the world’s plants more water-wise
July 24, 2017 5.18am EDT
Pep Canadell, Francis Chiew, Lei Cheng, Lu Zhang, and Yingping Wang
Land plants are absorbing 17% more carbon dioxide from the atmosphere now than 30 years ago, our research published today shows. Equally extraordinarily, our study also shows that the vegetation is hardly using any extra water to do it, suggesting that global change is causing the world’s plants to grow in a more water-efficient way.
Water is the most precious resource needed for plants to grow, and our research suggests that vegetation is becoming much better at using it in a world in which CO₂ levels continue to rise.
The ratio of carbon uptake to water loss by ecosystems is what we call “water use efficiency”, and it is one of the most important variables when studying these ecosystems.
Our confirmation of a global trend of increasing water use efficiency is a rare piece of good news when it comes to the consequences of global environmental change. It will strengthen plants’ vital role as global carbon sinks, improve food production, and might boost water availability for the well-being of society and the natural world.
Yet more efficient water use by the world’s plants will not solve our current or future water scarcity problems.
Changes in global terrestrial uptake of carbon dioxide, water use efficiency and ecosystem evapotranspiration during 1982-2011.
Boosting carbon uptake
Plants growing in today’s higher-CO₂ conditions can take up more carbon – the so-called CO₂ fertilisation effect. This is the main reason why the terrestrial biosphere has taken up 17% more carbon over the past 30 years.
The enhanced carbon uptake is consistent with the global greening trend observed by satellites, and the growing global land carbon sink which removes about one-third of all CO₂ emissions generated by human activities.
Increasing carbon uptake typically comes at a cost. To let CO₂ in, plants have to open up pores called stomata in their leaves, which in turn allows water to sneak out. Plants thus need to strike a balance between taking up carbon to build new leaves, stems and roots, while minimising water loss in the process. This has led to sophisticated adaptations that has allowed many plant species to conquer a range of arid environments.
One such adaptation is to close the stomata slightly to allow CO₂ to enter with less water getting out. Under increasing atmospheric CO₂, the overall result is that CO₂ uptake increases while water consumption does not. This is exactly what we have found on a global scale in our new study. In fact, we found that rising CO₂ levels are causing the world’s plants to become more water-wise, almost everywhere, whether in dry places or wet ones.
Growth hotspots
We used a combination of plot-scale water flux and atmospheric measurements, and satellite observations of leaf properties, to develop and test a new water use efficiency model. The model enables us to scale up from leaf water use efficiency anywhere in the world to the entire globe.
We found that across the globe, boreal and tropical forests are particularly good at increasing ecosystem water use efficiency and uptake of CO₂. That is due in large part to the CO₂ fertilisation effect and the increase in the total amount of leaf surface area.
Importantly, both types of forests are critical in limiting the rise in atmospheric CO₂ levels. Intact tropical forest removes more atmospheric CO₂ than any other type of forest, and the boreal forests of the planet’s far north hold vast amounts of carbon particularly in their organic soils.
Meanwhile, for the semi-arid ecosystems of the world, increased water savings are a big deal. We found that Australian ecosystems, for example, are increasing their carbon uptake, especially in the northern savannas. This trend may not have been possible without an increase in ecosystem water use efficiency.
Previous studies have also shown how increased water efficiency is greening semi-arid regions and may have contributed to an increase in carbon capture in semi-arid ecosystems in Australia, Africa and South America.
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So they are saying that plants do not have to work as hard….with more CO2
“summer time and the living is easy”…what’s not to like?
Another crack in the CAGW Satanic Gasses theme.
How could this not happen?
It should be obvious that plants need to leave their stomata open for less time in order to get the CO2 they need, thus less water will be lost.
Since water is the most important greenhouse gas, and since more CO2 means that plants lose less water to the atmosphere.
Would more CO2 also result in less water vapor in the atmosphere?
“global environmental change”
A new buzzword.
Except that this change is for the good.
Give them some time to figure out what the problem is.
Remember, the only bullet proof prediction is that: “We’re all gonna die!”
Can’t rule it out, but will take some ingenuity to figure out a way in which more greenery with less water use is a bad thing.
According to the greens that I’m familiar with. No change is good.
Walter Sobchak July 30, 2017 at 6:33 pm
“Remember, the only bullet proof prediction is that: “We’re all gonna die!” ”
Walter, can I help?
The watermelons’ prediction is
“You’re all gonna die, painfully. Or become our slaves/concubines.
Because we are the super-elite. Obviously.”
Fixed it for you.
Auto – not misanthropic, not a watermelon. But I repeat myself. [Mark Twain?]
This is an example of negative feedback or damping which is what you would expect in response to a change to the system (here, an increase in atmospheric CO2). If these and other attenuating responses didn’t exist, we wouldn’t be here to discuss climate change. The Earth would have suffered a runaway situation long ago, and we would never have had the time or the environment necessary to evolve.
The planet is greening and more plants are growing. link I suppose it’s possible that more total water is being used.
Of course the majority of land based flora use “fresh water” where oceanic flora utilise “salt water” and get their CO2 from it too and not as much from the atmosphere unless they are surface flora like algae and some seaweed. So land flora even with increasing CO2 is going to use more water in their growth…just more efficiently.
Actually, land plants won’t necessarily use more water to make the same amount or even more glucose. With 400 ppm of CO2 in the air instead of 280, they don’t need to leave their stomata open for as long to get the same amount of CO2, hence they lose less water to the air.
Flora add mass using the water and other nutrients from the soil with the CO2 from the air as the bulk of their Carbon. Just because they are not losing water from their respiration doesn’t mean they are not using more water to create their mass. Otherwise you could grow crops without irrigation or rain by just increasing the CO2 in the atmosphere. That the flora utilise water more efficiently does not mean they use less, because to grow mass they still need more water than what is stored in them and they still lose some water as pointed out. Flora will not reproduce without enough water to create their fruits, etcetera.
Leaf response to high CO2 is to structurally decrease the density of stomata & have larger size stomata. In low CO2 the opposite occurs; namely more stomata that are small in terms of it’s depth & pore size. Diffussion of water vapor in small pores is greater since it occurs in a proportion that is the INVERSE of the distance it has to travel in order to diffuse. In other words, with shorter to go there is more stomatal conductance outward of water via the smaller stomata of lower CO2 & since more of the smaller stomata can be arrayed in the leaf this adds to total water diffussion outward.
Big Al Here. Said it’s not so.
Is this also called negative feedback?
Good post but for this… “Yet more efficient water use by the world’s plants will not solve our current or future water scarcity problems.”
While true, it does not solve ALL our water needs and shortages, especially those caused by human error or politics, it is the single best reason we are not in a global crisis now.
To illustrate, instantly change our 2017 atmosphere to 280 ppm CO2. Now we need about 17 percent more water AND land, or a very large portion of humanity dies, made larger by the inevitable global war such food shortages would cause.
Do the population bomb globalist really hate CO2 because it allows billions to live?
Regarding water use, thousands of experiments show the increased bio-mass occurs with zero increase in water.
…also it should be added that each ppm increase in CO2 causes a fairly linear increase in plant growth and water efficiency, whereas the warming affect of each ppm increase in CO2 declines exponentially.
CO2 also makes plants more mineral efficient. More nitrogen efficient.
The 17 percent increase in water use efficiency was for the period of study, beginning in 1981 I think. However, CO2 had already increased substantially prior to the period of study. Its is actually considerably better then we thought!
Greens taking over
No. That is managed, by humans. Machu Picchu, for instance, was discovered covered in green.
Can we please engage our brains here before we strip off all our clothes and leap into the hot tub in Happy Valley’s garden of earthly delights?
I would not put it past Mother Nature to have freshened up said hot tub with a bit of lye.
She really is a bitch sometimes and in this case, the lye takes form in the reflections (of themselves) that these well intentioned folks see in their computer screens.
Where is the usual (for here) chorus of Models Models Shmodels Shmodels? huh?
Firstly, by raving about how good CO2 now apparently is, be very careful that you are not indirectly saying there really is a (CO2 caused climate) problem in the first place.
Not least because some bright spark somewhere sometime is gonna ask you:
“Is this sustainable? What if we come to depend on all this extra CO2 induced plant growth and then the extra supply of CO2 dries up?
IOW, is there a sustainable supply of CO2?
(We are talking 100′ & 1000’s of years, not just a few decades until a new oil well is sunk)
Not at all often for me, I’m gonna do an Appeal to Authority, particularly this guy: Justus von Liebig
2 considerations:
1: Are we/you/them really saying that CO2 is the limiting nutrient for plant growth on this planet?
Really.
Because if it is, why are farmers around the world spending billions of $$£££ on ‘artificial’ fertiliser, especially nitrogen.
Join some dots. How often here do we hear that ‘plants stop growing at CO2 of less than (say) 200ppm?
So even at 300ppm, there is no problem for plants with CO2 as a limiting nutrient.
2: Why are the oceans not greening also? There’s plenty plants grow in the water, and Lord only knows how many times we hear about CO2 dissolving in water so, why are not the ocean plants responding like the land based ones?
Maybe also because for plants in the ocean, CO2 is also not their limiting nutrient?
Do I hear a little voice from the back whispering ‘Ocean Iron fertilisation’…..
But on land, iron is not the limiter – just look around at all the red-coloured dirt there is.
That red colour is iron.
So, what would the limiting nutrient for land based plants?
For everywhere from relatively local Boreal forest to far-flung rain forest.
Something that obviously ‘travels’ well. (A gas would fit that criteria)
Something that might easily dissolve in water.
Something that is well proven to be a very effective fertiliser for land based plants.
Something that might have increased in parallel with the burning of fossil fuels.
Something may even be created with the fossil burning process itself?
Can’t think. sigh
I wonder if Volkswagen, the users of diesel engines or airline pilots know anything?
Very unclear post. Regarding nitrogen, well CO2 increases nitrogen efficiency as well. You appear disappointed that thousands of experiments show the benefits of CO2 increased bio growth are linear up to well over our ability to increase ppm. As to our capacity to pump CO2 into the atmosphere, I believe we are well capable of maintaining plus 550 ppm for thousands of years.
BTW Peta, they created a model based on real world observations, not contradicted by real world observations.
“We used a combination of plot-scale water flux and atmospheric measurements, and satellite observations of leaf properties, to develop and test a new water use efficiency models.”
I hope the difference is apparent.
Why do people forget that the majority of CO2 is created by Natural Sources exponentially and that Fossil Fuels are just a fraction of one ppm. Carbon Dioxide exponentially increases Bio-Mass that exponentially increases Bio-Mass by exponentially increasing Carbon Dioxide in the environment. Everything that is alive is a Carbon Sink by either first or secondary processes. Flora are the First carbon sinks that directly remove Carbon from the environment and fauna are secondary sinks that eat flora and other fauna that through respiration return more Carbon Dioxide into the atmosphere than they inhale and as byproducts. Where flora decay and return carbon into the atmosphere and environment or are burned to return carbon into the environment. Respiration of soils and volcanic activities add carbon dioxide into the environment, making what humans contribute a fraction of what the land itself creates in Carbon Dioxide.
johchi7,
The carbon cycle doesn’t create any CO2 if you look at the full cycle: Near as much CO2 is absorbed by plants and oceans in different seasons as CO2 is released in other seasons. That is a near-null operation. Humans emit about 6% of all natural CO2 influxes, but the natural outfluxes are about 3% larger than natural influxes, so about 3% of human releases (as mass, not the original molecules) remain in the atmosphere. That makes that near all recent CO2 increase in the atmosphere is human caused…
Studies done year’s ago show by volume humans exhale more CO2 than they inhale by volume…it’s how Fauna remove excess CO2 from themselves just by breathing. Humans have gone from millions at the end of the Last Ice Age to over 7.4 billion. Just as all other fauna have exponentially increased in that time frame and added exponentially to the CO2 in the environment. Combined fossil fuels, cement manufacturing and other industrial sources and human caused deforestation only amounts to 0.05% of the Carbon Dioxide by pre 2013 sources, and humans are counted in the Natural Sources. In your kindergarten models of the Carbon Cycle an animal is added to represent fauna by eating flora and adding CO2 to the environment. They don’t show that the material waste of fauna degradation or decay of flora adda to it. It also doesn’t include fires of any natural sources or others. How do you measure burning flora that has CO2 created carbon from hundreds of year’s ago to today? Or a CO2 molecule that has been in the environment for hundreds of year’s being used by a flora today?
“So even at 300ppm, there is no problem for plants with CO2 as a limiting nutrient.”
YES, it most certainly is.
Optimum level is 1000 ppm plus.
300ppm is very limiting of growth.
” Why are the oceans not greening also?”
They are.
Actually, the greening of the oceans is limited by iron. Atmospheric CO2 is a resource, not a problem. We can feed hundreds of millions of people and revive our ocean pastures by adding a small amount of iron to the world’s fisheries. See Russ George’s experiment off the west coast of Canada.
[Make sure your email address is correct to avoid ending up in moderation. -mod]
“How often here do we hear that ‘plants stop growing at CO2 of less than (say) 200ppm?
So even at 300ppm, there is no problem for plants with CO2 as a limiting nutrient.”
Humans can live on a slice of stale bread and a glass of water a day.
But is that what you would wish on plant life.?
You seem to have missed the fact that they said they tested their model. That’s why there’s no outcry of “Models Shmodels.” That means the model was validated against real-world data.
“What if we come to depend on all this extra CO2 induced plant growth and then the extra supply of CO2 dries up?”
Nuclear energy of some sort to release CO2 from limestone. Once people get over this superstitious CO2-HATRED, they will start to realise that MORE CO2 is needed, NOT LESS.
The imperative to increase CO2, once realised, is not an issue.
If push comes to shove, and levels of CO2 must be raised after the exhaustion of all of the coal, oil, and natural gas, there is still the energy intensive operation of liberating CO2 from calcium carbonate (probably using electricity from nuclear fission/fusion power to supply the process heat). Forcing the early extinction of all calcium carbonate creating life forms to keep everything else from dying with them is not an option. Hopefully, the required volume of limestone, shale, and other calcium carbonate rock will not be too large, as all of that lime will start pulling in CO2 if it gets wet, so it must be sequestered. With all of the doubt that mining Helium3 on the Moon will ever be cheaper than making Tritium on earth and waiting for it to decay into Helium3, harvesting CO2 from Venus to ship back to Earth is probably far beyond cost effective.
The fact that green plants nearly extinguished all life by evolving a new protein, lignin, that required several millions of years to encourage the evolution of something that could eat it sheds a new light on the search for extraterrestrial intelligence, as examination of the one example of a life bearing planet that we know of proves that Biospheres are transitory things and lifeless planets are the norm.
The ocean plants are not limited by the evaporation of water through their stomata, as they are immersed in liquid water.
Peta from Cumbria:
Why are the oceans not greening also?
Because CO2 – and its derivatives, mainly bicarbonates and carbonates, are not the limiting factor for plant growth in the oceans. Iron, phosphates, nitrogen,… are the limiting factors. Although there are some more algal blooms with more CO2…
Moreover, the ~35% CO2 change in the atmosphere only resulted in a ~3.5% change in CO2 + derivatives in the ocean surface waters, due to the Revelle/buffer factor.
That is the result of the buffer chemistry of the ocean waters, which allows a 100% change for free, gaseous CO2 in solution – per Henry’s law – for a 100% change of CO2 in the atmosphere, but as free CO2 is only 1% in seawater, that only means a doubling of total inorganic carbon species from 1% to 2%. The rest is from the increases of bicarbonates and carbonates, which in total is about 10%, not 100%.
As far as I remember, iron fertilizing of the ocean surface had initially some success, but at the end all what happened was a faster total carbon cycle from plankton via fish back to CO2 and the total yield (as CO2 uptake) was rather meager…
I saw a programme on television last night that said 25% of the plant biomass was created on our foreshores.
Please Vuckcevic where are those marvelous greenhouses situated?!
not vuckcevic but;-)
i also saw those pics
its in Japan i gather some island towns that have depopulated as the young left for work and the oldies moved out
stunning arent they?
id move there WITH the greenery left in place outside at least 😉
theyd be very well built places
search deserted japanese homes/islands and i reckon youll find it
Someone will win the Nobel Prize by discovering the photosynthesis….
Only if they have the track record of favored bias creds
Uiih…..
“Our confirmation of a global trend of increasing water use efficiency is a rare piece of good news when it comes to the consequences of global environmental change. It will strengthen plants’ vital role as global carbon sinks, improve food production, and might boost water availability for the well-being of society and the natural world.”
For goodness` sake, the fundamental stock on which all life on Earth including man itself depends on, the plants, are in the eyes of this “researchers” a “rare piece”. This is not a rare piece, rather the very best message since the modern man set his foot out of africa. Whether in dry habitats or in humid habitats, more CO2 makes plants very good and this is very good for man..
The next thing they will be telling us is the warming in the last 150 years has caused by solar cycle changes rather than AGW.
C3 plants (trees, cereal crops, and shrubs) lose roughly 50% of the water they absorb due to transrespiration (loss of water from the plant’s stomata.) When CO2 rises C3 plants produce less stomata which reduces water loss in the plant.. This results in more water at the root of the plant which enables synergistic bacteria on the roots to produce more nitrogen byproducts which increases plant growth.
A higher level of atmospheric CO2 enables plants to make more effective use of water and enables the plant to survive in regions of low water such as deserts. Higher levels of atmospheric CO2 are beneficial to biosphere.
http://www.sciencedaily.com/releases/2003/05/030509084556.htm
http://news.nationalgeographic.com/news/2009/07/090731-green-sahara.html
In very simple words: the plants can finally throw away their oxygen bottles and finally breathe freely. This shows us, however, that plants grew throughout the Holocene under bad, not optimal, conditions.
CO2, its what plants need! And humans need plants. Win/win.
the gum trees here in Aus have been growing so fast theyre splitting their cambium vertically!
and have been for 5+ yrs
and i am talking HUGE redgums like in my yard with bases 2people can stand outstretched arms around diameter 6ft or more
Completely anecdotal observation – We have had a very dry summer here in eastern Colorado & I have heard multiple people comment on how they are surprised how green everything has stayed, which I have noticed as well. Perhaps same phenomena as this paper proposes?
I noticed a similar thing here in New Hampshire last summer. We were in drought conditions but everything stayed green while we expected them to turn brown. This was particularly true of a lot of the lawns and shrubbery. The farms, on the other hand, did have some issues because their irrigation ponds dried up.
Here in Arizona I’ve seen the Mesquite and Palo Verde tree’s go from 2 – 3 bean crops per year to 5 last year along with plant’s staying green longer and throughout the winters. Farm crops have increased their yields over the year’s too with longer a growing season too. I haven’t farmed in over 2 decades, but I wonder if farmers are seeing a reduced water need?
Check with county ag offices and you can probably get some water use stats. Just pretend to be an ecowarrior fighting the jihad to save Gaia and you should get plenty of cooperation.
I’ll not stoop that low to rub a snakes belly. Thanks for the lol though. First off when it comes to ordering water from SRP to irrigate a field you order enough to cover the acreage and not what the expected use of the crop is going to use. Second you order the water during the time it’s needed between cuttings for crops like alfalfa and when the CO2 is higher the alfalfa grows faster and requires harvesting more often before it blooms. Crops like alfalfa used to be cut closer to once every 28 to 30 days and now every 26 to 28 days with larger yield and therefore more harvest in the same time frame and by fall they are getting a greater yield on the last harvest than over 20 years ago. When the water is available the plants will use as much as they can get. So just because they don’t need as much water with higher CO2 doesn’t mean they will not use it in creating mass when it’s there at their roots. That they are not giving as much water out from their leaves to get the CO2 is more efficient and cannot be denied. But until the plant reaches it’s maximum growth it will use the water as fast as it can get it to build its mass because the water it circulates in it is all part of the photosynthesis with the CO2.
“but I wonder if farmers are seeing a reduced water need?” Asking county ag offices would be a good start to answering this question, all I am saying.
As to cutting alfalfa and hay, I can say that here in western PA it has been cut in a shorter cycle in the last few years. Corn has run about the same, this wet spring meant a lot of corn was planted a bit late but appears to be hitting picking about the normal time of summer. Plants can be a bit unpredictable.
In response to alfalfa growth (& being now different than corn): legumes, like alfalfa, are the C3 plants with an average 56% greater biomass production capability under enriched CO2 experiments. In comparison the C4 plants, like maizen under same entichment average 8% more biomass. To broaden the comparison the C3 plants that are not legumes average 26% grester biomass production under enriched CO2 research.
While discussing maize, the following may intrrest some still following this thread. Enriched CO2 studies show the number of seeds (kernels) for maize averages 5% greater. Contrast this with wheat, which can produce an average of 15% more seeds.
The mass of individual seeds in legumes (C3 plant) under enriched CO2 increases by an average of 8%; while in C3 plants that are not legumes this feature goes up on average 3%.
However, in C4 plants seed mass does not seem to increase (some report small decrease).
As per my cited free full text html cited below: “Plant reproduction …meta-analysis …79 crop ….”
Adaptations — so they are saying the plants have evolved in 50 years? Genius!
No, nothing new, plants evolved in much higher CONditions then 400 ppm. Just plants operating as nature made them eons ago.
Excerpted from above commentary:
So, the claim is that the INCREASE in summertime “growing-greening” of the terrestrial biosphere during the past 30 years (1987-2017) has been “sucking” 17% more CO2 out of the atmosphere.
The first question is, …… is that 17% the yearly average “suck-down” for each one of said 30 years, or is that 17% “suck-down” only applicable to year 2017?
And then they claim that the “17% increase in carbon sink” …… has actually resulted in removing one-third (33%) of all anthropogenic emitted CO2 from the atmosphere. Again, was that on a yearly basis or just for year 2017?
And the big question is, …….. what is the name of that Magic Calculator they used for determining that the “17% ‘suck-down’ increase in biomass carbon sink” …… is equal to “33% of all anthropogenic emitted CO2”?
“Rare good news”?
So in the view of the climate catastrophists a fundamental huge benefit is “rare good news”.
What utter wankers the climate kooks are.
Massive objectively measurable greening in the double digits is marginal, while contrived non-data driven claims are major signs of doom.
Climate doom obsession has degraded every area that it infects.
The observation that more efficiency in plant growth leads to more plants seems to be the biological version of Jevon’s Paradox. In the 1850s as steam engines proliferated, the greens of the day proposed that the way to curtail the growth of coal demand was to make the engines more efficient. The effect was to make them proliferate even faster as they fit into increasingly marginal and cost sensitive, but much more numerous, applications. Demand for coal grew even faster as a result. The plants seem to be following the same non-linear path. As they proliferate in ever more marginal environments, they will suck up ever more CO2, until they reach some physical limit. I would say the earth is doing quite nicely, thanks.
I wrote about Jevon and the wealth inequality impact of artificially limiting energy availability here:
http://constructalinfonomics.org/the-wealth-imperative/
Thanks Mark, an economic reality, and the reason green statists want to make the cost of electricity soar.
A little off topic but the mention of water shortages always makes me wonder whether population growth affects availability of water in as much as how much water is in each person’s body.
If on average a persons weight is 57% water multiplied by 7.5 billion people or thereabouts, thats a lot of water. You can tell I’m not a scientist!! Something that’s puzzled me for a long time.
Juliet, we live on a water planet. Virtually all water shortages are due to political reasons relating to purposefully expensive energy, poor planning, and conflicts at every government level. ( see California as a classic example of all of the above)
There are real issues of water depletion in some water tables, all solvable by today’s technology.
However I can give you this estimate…
“Anyway, what we really want to know is how big a piece of land we’d need to hold everyone—all 7.3 billion of us. And the answer is, a 27km x 27km (16.8mi x 16.8mi) square.”
Note. This is 9 adults per sq meter. Not their water content. Which would maybe be a lake this size yet very shallow. Maybe two feet deep for a wag.
Thank you for your very kind replies – the loud thud you may have heard was a very big penny dropping… I will puzzle no more.
It sounds like our atmosphere is getting back into the balance that maintained through so much of the staggering growth of the ecosphere over the last few billion years. The CO2 anemia ia going away. I can think of worse situations. Let’s see if we can keep it.
I have always found it amusing to think of this in the opposite manner. Lets just say that environmentalists were interested in increasing biodiversity and making the planet more healthy. What would people recommend?
Warm regions carry more biodiversity.
Plant life underpins an ecosystem, so increasing plant growth would be good for biodiversity.
So what do environmentalists want? They want to make the planet colder and reduce plant food.
“They want to make the planet colder and reduce plant food.” Which will force down the number of humans, their oft repeated primary goal. And yet they refuse to eliminate themselves and their progeny in order to achieve it. Funny how that works, they always want to get rid of other people and their children.