Climate change: More carbon dioxide leads to fewer clouds

Sep 04, 2012
Presumably fewer clouds will develop in the future over the grass: The increase in carbon dioxide in the atmosphere causes an evaporation decrease of plants. As a result fewer cumulus clouds form, more sunlight reaches the ground - the climate change intensifies. Credit: Bart van Stratum

(Phys.org)—The warmer the air, the more water can evaporate: a simple relationship familiar to us from everyday life. Researchers from Germany and the Netherlands have now established that this is not always the case: although an increase in the greenhouse gas CO2 makes the climate warmer, it also allows less water to evaporate. Plants, with their billions of tiny leaf pores, are the cause of this apparent contradiction. They influence the gas and moisture content of the air around them. Using new calculations of an atmospheric model, the researchers found that this sets in motion a cascade of processes, finally resulting in global warming.

"We wanted to know how the foreseeable rise in CO2 would affect cloud formation in temperate and what part the vegetation plays in this," says Jordi Vilà-Guerau de Arellano from the University of Wageningen in the Netherlands. Working with colleagues from the Max Planck Institutes for Chemistry and Meteorology, the made use of, for the first time, a computer model that takes account of the soil, water cycle, and growth processes of plants. The model results highlight how local and daily variable processes, through turbulence, can influence the atmosphere on larger scales.

The scientists simulated three scenarios for their analysis: a doubling of the CO2 in the atmosphere from the current 0.038% to 0.075%, an increase in the average by two degrees Celsius and a combination of both. The calculations represent the conditions expected for the year 2100 and compared to 2003 values based on scenarios from the (IPCC).

The researchers established that some land-vegetation-atmosphere exchange processes respond more strongly to increasing CO2 and than others. Doubling the CO2 in the atmosphere actually starts a cascade of processes beginning with the physiological response of plants to the higher CO2 concentration. The trigger of the chain of events is that plants regulate the exchange of water vapor and carbon dioxide with the atmosphere by the opening and closing of the leaf pores - the stomata.

At higher CO2 concentrations plants close their stomata

The cascade starts harmless: in the double CO2 scenario, the stomata close earlier since the plants can assimilate the necessary CO2 for photosynthesis more optimally. As a result, less moisture is evaporated by the plants and there is overall less water vapour introduced into the atmosphere.

Consequently, fewer cumulus clouds are formed, which means that the Earth's surface becomes warmer, as the sun's rays hit it directly and are not reflected by clouds. Then, warmer air creates more turbulence in the atmosphere near the surface, and in consequence there is more heat and less moisture transported. The earth and the atmosphere thus heat up through the plants' response to the higher CO2 levels.

The researchers have thus found another in the climate system, a self-reinforcing process. This feedback mechanism did not develop in the second scenario, in which the atmosphere only warms by two degrees Celsius without the effect of higher concentrations of the CO2 on plants.

Evaporation will fall by 15%

The researchers then simulated a third scenario in which they increased both the CO2 levels and the temperature. "Positive effects on cloud formation include the ability of the warmer atmosphere to hold more water or increase the growth of biomass. However, they are only partly able to compensate for the reduction in cloud formation," according to Jordi Vilà. "Evaporation will fall by 15%. The atmospheric boundary layer dries out, and fewer clouds form," adds Jos Lelieveld, Director at the Max Planck Institute for Chemistry in Mainz.

The study thus shows that diminished evaporation from has a direct impact on . Chiel van Heerwaarden from the Max Planck Institute for Meteorology emphasizes: "The calculations show an important feedback mechanism between the vegetation and physical climate processes." In future, the researchers want to extend their analysis to the Amazon to test the effects of increasing CO2 levels on tropical regions.

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More information: Jordi Vilà-Guerau de Arellano, Chiel C. van Heerwaarden and Jos Lelieveld, Modelled suppression of boundary-layer clouds by plants in a CO2-rich atmosphere, Nature Geoscience, September 2, 2012

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dogbert
1.6 / 5 (25) Sep 04, 2012
GIGO.
The key here is simulated. Computer programs produce whatever they were written to produce.

NotParker
1.5 / 5 (26) Sep 04, 2012
They are trying to explain why the earth stopped warming 15 years ago, so they are attempting to claim more clouds caused less sunshine leading to no increase in temperatures.

The trouble is that global brightening is a real studied phenomena and global brightening occurred in the 80s and 90s which probably caused a small increase in temperature.

Global Brightening occurred in the 20s and 30s and 40s too.
Claudius
2 / 5 (16) Sep 04, 2012
I have not seen a reference to this recent article in Phys.Org:

"The phase relation between atmospheric carbon dioxide and global temperature"

Highlights from the article:

"-Changes in global atmospheric CO2 are lagging about 11–12 months behind changes in global sea surface temperature.
-Changes in global atmospheric CO2 are lagging 9.5-10 months behind changes in global air surface temperature.
-Changes in global atmospheric CO2 are lagging about 9 months behind changes in global lower troposphere temperature.
-Changes in ocean temperatures appear to explain a substantial part of the observed changes in atmospheric CO2 since January 1980.
-CO2 released from use of fossil fuels have little influence on the observed changes in the amount of atmospheric CO2, and changes in atmospheric CO2 are not tracking changes in human emissions."

http://www.scienc...12001658

rubberman
3.1 / 5 (17) Sep 04, 2012
They are trying to explain why the earth stopped warming 15 years ago, so they are attempting to claim more clouds caused less sunshine leading to no increase in temperatures.

The trouble is that global brightening is a real studied phenomena and global brightening occurred in the 80s and 90s which probably caused a small increase in temperature.

Global Brightening occurred in the 20s and 30s and 40s too.


You might want to look into NotParker brightening. It might help you to focus on the topic of the article.

GIGO.
The key here is simulated. Computer programs produce whatever they were written to produce.



Spoken like a person truly ignorant of modelling. THis one is easy enough to do a real world simulation for, if they want to test the models accuracy.
nappy
1.3 / 5 (21) Sep 04, 2012
This dog will not hunt. IF that were so, the atmosphere could not have changed from the heavily CO2 laden thing prior to photosynthetic plants to the oxygen laden atmosphere we now enjoy. More global warming claptrap.
rubberman
3.4 / 5 (16) Sep 04, 2012
This dog will not hunt. IF that were so, the atmosphere could not have changed from the heavily CO2 laden thing prior to photosynthetic plants to the oxygen laden atmosphere we now enjoy. More global warming claptrap.


You might want to re-read the article. This has nothing to do with carbon sequestration.
NotParker
1.5 / 5 (20) Sep 04, 2012

You might want to look into NotParker brightening.


Why so rude all the time?

"There is increasing evidence that the amount of solar radiation incident at the Earth's surface is not stable over the years but undergoes significant decadal variations. Here I review the evidence for these changes, their magnitude, their possible causes, their representation in climate models, and their potential implications for climate change. The various studies analyzing long-term records of surface radiation measurements suggest a widespread decrease in surface solar radiation between the 1950s and 1980s ("global dimming"), with a partial recovery more recently at many locations ("brightening"). There are also some indications for an "early brightening" in the first part of the 20th century."

http://www.agu.or...70.shtml

rubberman
3.2 / 5 (13) Sep 04, 2012
"Why so rude all the time?"

As usual, your initial comment is off topic from the article and is clearly intended to spark yet another circular debate about your views on climate change. Nothing in your comment relates to the article other than your rediculous perception of a hidden message intended by the author (the only reference to climate change in the whole article is when they fail to use the acronym IPCC) . I support the theory of global brightening as a result of both a decrease in atmospheric particulates and minor variances in solar output, and, if this (the article) is correct a decrease in global cloud cover. As I said in my previous post, a real world experiment can verify or discount the model results, but if verified the conclusion regarding cloud formation is valid.
NotParker
1.3 / 5 (23) Sep 04, 2012
"Why so rude all the time?"

As usual, your initial comment is off topic


Nonsense. I was mocking this article for trying to claim CO2 causes more clouds.

More clouds = less warming. Less clouds = more sun = more warming.

And I was pointing out very serious scientists are investigating global brightening and dimming and it has been going on for the whole 20th century and has nothing to do with CO2.
rubberman
3.4 / 5 (18) Sep 04, 2012
"Nonsense. I was mocking this article for trying to claim CO2 causes more clouds." - NP

The title of the article: "More Carbon Dioxide leads to fewer clouds"

And you wonder why he calls you Parkertard......
Caliban
4.3 / 5 (11) Sep 04, 2012


Nonsense. I was mocking this article for trying to claim CO2 causes more clouds.

More clouds = less warming. Less clouds = more sun = more warming.

And I was pointing out very serious scientists are investigating global brightening and dimming and it has been going on for the whole 20th century and has nothing to do with CO2.


As rubberman points out, NutPecker, the article speaks of an effect that is the exact opposite of what you claim it states.
So it is apparent that you at least remembered to take your moron pill today. Probably even took two.

And your bullshit handwaving about dimming/brightening is just another attempt from you to obcsure what is already understood to be the mechanism for the observed variability this century -anthropogenic emission of aerosols.

You are indeed a tiresome little insect, much like the mighty cockroach, requiring a determined, ongoing effort to exterminate.

That crunching sound as you are trod upon is immensely gratifying.
NotParker
1.2 / 5 (22) Sep 04, 2012


Nonsense. I was mocking this article for trying to claim CO2 causes more clouds.

More clouds = less warming. Less clouds = more sun = more warming.

And I was pointing out very serious scientists are investigating global brightening and dimming and it has been going on for the whole 20th century and has nothing to do with CO2.


As rubberman points out, NutPecker, the article speaks of a ...


... computer model with predictions so far in the future they cannot be checked.

Your brain is so tiny it confuses reality with a computer program so simple it makes pong look like the most current video game.
packrat
2 / 5 (8) Sep 04, 2012
If what the article says is correct wouldn't that also mean that plants shutting down their pores would also cause them to need less watering?

So what we seem to have as an end result is possibly less clouds but at the same time less rain needed for the plants?
Sanescience
2 / 5 (4) Sep 04, 2012
While of some interest, I find considerations incomplete. The central statement is opening and closing based on CO2 of stoma controls amount of moisture released. Not mentioned was if respiration was accelerated while the stoma was open. Does moisture only exit via stoma. Does moisture wait in the ground only to be released by the plant, or does it evaporate from the soil if not by the plant. Do plants always limit their uptake of CO2 by a fixed quantity or do they grow faster and produce greater numbers of stoma via higher leaf count that collectively counter shorter stoma open times. Does extended exposure to CO2 cause plants to adopt new methods to extend duration of respiration. Is water saturation at low altitudes only achieved through plant respiration? Is water vapor at high altitudes strongly correlated with ground levels or is ocean weather a dominant source of atmosphere humidity.

Just a few related issues I can think off the top of my head.
Caliban
3.9 / 5 (7) Sep 04, 2012
Nonsense. I was mocking this article for trying to claim CO2 causes more clouds.

More clouds = less warming. Less clouds = more sun = more warming.

And I was pointing out very serious scientists are investigating global brightening and dimming and it has been going on for the whole 20th century and has nothing to do with CO2.




Who knew an insect could hop on the backcycle and pedal so furiously?

Careful, NutPecker --it may not be possible for you to avoid a self-inflicted crush wound as you step all over yourself trying to escape the asininity of your own comments.

Vendicar_Decarian
4.2 / 5 (10) Sep 04, 2012
They are of course, written to produce correct results.

"Computer programs produce whatever they were written to produce." - DogberTard

Vendicar_Decarian
4 / 5 (12) Sep 04, 2012
Oh, that is simple to explain...

It didn't.

http://www.woodfo...11/trend

http://www.woodfo...98/trend

"They are trying to explain why the earth stopped warming 15 years ago" - ParkerTard

You are lying.
Vendicar_Decarian
4.1 / 5 (13) Sep 04, 2012
Today a new minimum Arctic ice area was reached.

The current value is 2.37 million square kilometers.

This is the lowest Arctic ice area ever recorded in human history.

Several days in the traditional ice melt season remain.

http://arctic.atm...ive.html

ParkerTard has been posting links to charts showing ice levels increasing.

However the charts ParkerTard have been posting are not for the entire arctic, but for a small region just outside the arctic ocean.

"Your brain is so tiny it confuses reality with a computer program" - ParkerTard

ParkerTard is a congenital and perpetual liar.
Vendicar_Decarian
3.9 / 5 (11) Sep 04, 2012
Poor ParkerTard. He can't being himself to realize that the article is saying the exact opposite.

Perhaps the title confuses him...

'More carbon dioxide leads to fewer clouds'

"Nonsense. I was mocking this article for trying to claim CO2 causes more clouds." - ParkerTard

Poor mentally diseased ParkerTard.
Vendicar_Decarian
3.9 / 5 (11) Sep 04, 2012
Not doubt your psychiatrist is concerned with your dimming over the last few decades.

"And I was pointing out very serious scientists are investigating global brightening and dimming" - ParkerTard

ParkerTard's mental disease is in the terminal phase.
runrig
4 / 5 (8) Sep 05, 2012
Nonsense. I was mocking this article for trying to claim CO2 causes more clouds.

Careful, NutPecker --it may not be possible for you to avoid a self-inflicted crush wound as you step all over yourself trying to escape the asininity of your own comments.

You are indeed a tiresome little insect, much like the mighty cockroach, requiring a determined, ongoing effort to exterminate. That crunching sound as you are trod upon is immensely gratifying.


LOL Caliban. It's an interesting avenue of psychology isn't it? That things can be turned around 180 degs to fit into their ( there is more than one on here - although he may have understood that plural possessive pronoun ) world view. Distortion so extreme it can indeed be seen as a mental disease.

It is a battle unable to be won given such unfathomable mental function but it is a battle that has to be fought. We must always deny ignorance
Eikka
2.8 / 5 (9) Sep 05, 2012
Wouldn't the lack of daytime evaporation also reduce the number of nighttime clouds, leading to a higher heat loss during the night?
PStrand
2 / 5 (9) Sep 05, 2012
Of course, higher concentrations of CO2 cause less water vapor to be released from the leaves through photosynthesis. But, there is a flip side in the equation. More CO2 enhances plant growth and leads to better drought resistance. The result is that the biomass increases. More biomass results in an increase of photosynthesis leading to increase in the release of water vapor. Higher plant growth also creates more shadows which results in more moisture on the ground which can stay on the ground hidden from sunlight for longer. The end result is that there probably is no or little change. Of course if they say that they may lose their funding which is counter to the AGW meme.
rubberman
1.7 / 5 (6) Sep 05, 2012
PStrand has chosen to point out a flip side in the plant growth equation by assuming that only one variable (CO2 concentration) changes. What he fails to comprehend is that by changing CO2, in most cases (not every single location on earth will see climatic changes) that changes the rest of the variables in the equation. The droughts in the US/Spain for example...having an abundance of CO2 is useless if it stops raining. Plants grow where they do because the local climate supports it, changing climate = changing biomass that a region supports. Crops have a high end tolerance for temperature, too many days on the high side of what they are accustomed to result in lower yields, again, regardless of atmospheric CO2 content.

@sane - Good questions, I googled answers to them...you can too!
RealityCheck
2.2 / 5 (13) Sep 05, 2012
Hi NotParker. No comment on your latest faux pas, for it's self evident, and says volumes about your approach to issues which you seem to have 'immutable' preconclusions about irrespective of the facts you come across which don't support your preconclusions. I will admit to being fascinated by your posts as examples of 'free will' choice to 'bias/denial' and its abstract/real motivations. Are you a lobby group 'hired gun'? A religious anti-science type who will wilfully contradict any scientific analysis for personal/religious stance because evolution theory/fact is also science which makes certain religious beliefs come across as fantasy? Or is it a political thing with you and your widespread denial stances? In any case, you seem a perfect study of contrariness as free-will choice. I will have to point Sasuga (in a 'free will' article discussion) at your posts as support for my observation that free will exists (behind your faux pas/argument motivations) irrespective of 'inputs'.

RC
RealityCheck
2 / 5 (12) Sep 05, 2012
Hi Eikka:
Wouldn't the lack of daytime evaporation also reduce the number of nighttime clouds, leading to a higher heat loss during the night?

You put your finger on the button, mate! That is why increased/widespread 'blanket' of atmospheric CO2 is so dangerous. Unlike water/vapour which cycles in a 'patchy' distribution/events, increased CO2 now extends above-cloud altitudes and distributed ubiquitously. It acts continuously day and night, catching/reflecting back down much heat radiation from clouds and land/ocean everywhere. Under previous CO2 levels, water 'local/incidental' cloud/vapour cycle/reflection 'coverage' played a role (less versus more, day versus night) as you point out, this is now overshadowed (from above and below) by CO2 absorption/re-radiation downwards all the time, day AND night even where cloud is absent to intercept ground radiation. The ubiquity and 'always on' activity of greater CO2 triggers 'tipping point' warming/release of methane. Not good!

RC.
NotParker
1.6 / 5 (14) Sep 05, 2012
Less air pollutions leads to fewer clouds.

http://sunshineho...erlands/

I suspect the researchers did not control for that.
PinkElephant
5 / 5 (6) Sep 05, 2012

Less air pollutions leads to fewer clouds. I suspect the researchers did not control for that.
The effect is additive, and not mutually exclusive with the one under discussion.

@Eikka, PStrand,

Why do so many here keep on assuming that professional researchers and subject matter experts are somehow stupid and/or ignorant enough not to think of obvious issues that are glaring even to laymen like yourselves?

Here's a link to the actual paper (where you can see the paper's abstract and links to figures):

http://www.nature...554.html

Just looking at the abstract and the figures, it's very obvious already that the simulation was complete enough to address the factors that concern you, and I'd have to imagine it addressed an entire host of other factors that you won't even be knowledgeable enough to anticipate in the first place.

*Sigh*....
Caliban
3.8 / 5 (4) Sep 07, 2012
Nonsense. I was mocking this article for trying to claim CO2 causes more clouds.

Careful, NutPecker --it may not be possible for you to avoid a self-inflicted crush wound as you step all over yourself trying to escape the asininity of your own comments.

You are indeed a tiresome little insect, much like the mighty cockroach, requiring a determined, ongoing effort to exterminate. That crunching sound as you are trod upon is immensely gratifying.


LOL Caliban. It's an interesting avenue of psychology isn't it? That things can be turned around 180 degs to fit into their ( there is more than one on here - although he may have understood that plural possessive pronoun ) world view. Distortion so extreme it can indeed be seen as a mental disease.

It is a battle unable to be won given such unfathomable mental function but it is a battle that has to be fought. We must always deny ignorance



That dovetails very nicely with my way of thinking.

Soldier on, runriq.
VendicarD
2.3 / 5 (7) Sep 08, 2012
Wrong again Tard Boy.

"More clouds = less warming." - ParkerTard

The warming/cooling effects of cloud formation is dependent upon where and at what altitude they form.

Clouds forming over the arctic ice cap in winter increase warming for example, as do high altitude clouds. Low altitude clouds tend to induce cooling.

Really ParkerTard. You have been yammering nonsense about the ongoing warming globe for years.

And you still can't get even the basics right.
VendicarD
2.1 / 5 (7) Sep 08, 2012
"Less air pollutions leads to fewer clouds." - ParkerTard

This has been known for over 100 years, and of course is one of the reasons why the higher pollution levels of the 40's and 50's produced reflective smogs and clouds that reduced global temperatures, until the 70's when U.S. smokestacks were forced to clean up their act by the EPA.

It looks to me like we have a similar situation in China, and that their sulfate emissions - along with other particulates, including the emissions from other pacific rim nations are creating similar negative effects on global temperature.
NotParker
1.6 / 5 (14) Sep 08, 2012

Why do so many here keep on assuming that professional researchers and subject matter experts are somehow stupid and/or ignorant enough not to think of obvious issues that are glaring even to laymen like yourselves?


Eric Steig is a great example of why "climate scientists" should never, ever be trusted. Every word and graph and bit of data should be double and triple checked.

They lie.

http://noconsensu...-genius/

mosahlah
1.5 / 5 (11) Sep 09, 2012
What I take first from this,.. computer models of the effects of carbon dioxide on global warming were inaccurate before this revelation, but now they think they have it right. Very reassuring.
mosahlah
1.5 / 5 (11) Sep 09, 2012
This has been known for over 100 years, and of course is one of the reasons why the higher pollution levels of the 40's and 50's produced reflective smogs and clouds that reduced global temperatures, until the 70's when U.S. smokestacks were forced to clean up their act by the EPA.

It looks to me like we have a similar situation in China, and that their sulfate emissions - along with other particulates, including the emissions from other pacific rim nations are creating similar negative effects on global temperature.

- venereal dude.

What happen to the hockey stick? I never hear the admission from the passionate that something went wrong with the prediction. I expect we will be spending the next fifty years listening to one explanation after another for the delay of the impending global warming apocalypse. Just maybe predicting and mitigating global climate change (I love the new term) wasn't so simple after all?
runrig
4.5 / 5 (8) Sep 09, 2012

What happen to the hockey stick? I never hear the admission from the passionate that something went wrong with the prediction..... Just maybe predicting and mitigating global climate change (I love the new term) wasn't so simple after all?


That's because nothing went wrong - the basic fact of warming temperatures is correct see ...http://en.wikiped...troversy
"Further support for the "hockey stick" graph came from a new method of analysis using Bayesian statistics developed by Martin Tingley and Peter Huybers of Harvard University, which produced the same basic shape, albeit with more variability in the past, and found the 1990s to have been the warmest decade in the 600 year period the study covered......."

Also the term "climate change" best fits what is happening, ie there is much more variability in climate and some places can be cooler for a time. Yes it is complex and I am not aware of any scientist claiming it wasn't.
runrig
5 / 5 (6) Sep 09, 2012
What I take first from this,.. computer models of the effects of carbon dioxide on global warming were inaccurate before this revelation, but now they think they have it right. Very reassuring.


A little bit maybe but the effect would be a warming one give the missing cloud would have been low based and over land.

That's science. A prediction is made ( these days a complex computer code ) and is tested. If in error it's then modified to take account of new evidence.

I hope you are reassured.
VendicarD
2.7 / 5 (7) Sep 10, 2012
Which one? There are at least a dozen in the Peer Reviewed Climate Science literature?

"What happen to the hockey stick?" - MosahaTard

What prediction? All of the Hockey Sticks are based on paleo-climatology, and as such are the results of the analysis of recebt historical global temperaturs.

"I never hear the admission from the passionate that something went wrong with the prediction." - MosahaTard

You seem to be quite confused.

Lack of oxygen?
VendicarD
3 / 5 (6) Sep 10, 2012
It is best if those who don't know the fundamentals of climate science, avoid making foolish predictions about the future of climate science.

"I expect we will be spending the next fifty years listening to one explanation after another for the delay of the impending global warming apocalypse." - MosahaTard

Don't you agree?
VendicarD
3 / 5 (6) Sep 10, 2012
ParkerTard's link deserves a second look.

http://vimeo.com/33235545

Good lecture by Dr. Steig.

"Eric Steig is a great example of why "climate scientists" should never, ever be trusted." - ParkerTard

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