Plants won't boost global warming as much as feared: study

March 16, 2016 by Marlowe Hood
When air temperatures climb, plants start to "exhale" extra CO2 with no change in the amount absorbed
When air temperatures climb, plants start to "exhale" extra CO2 with no change in the amount absorbed

Vegetation will release far less extra carbon dioxide in a warming world than previously assumed, giving humans a bit more room in the fight against climate change, scientists reported Wednesday in Nature.

Despite this good news, efforts to curb greenhouse-gas emissions must still be stepped up to avoid dire climate impacts, the researchers cautioned.

Earth's plants and soil microbes absorb and exude huge quantities of heat-trapping CO2, the main driver of .

Over the course of a year, land-based flora emit—in a process called respiration—117 to 118 billion tonnes of carbon into the atmosphere, six times as much as humans release by burning fossil fuels.

At the same time, through photosynthesis, they soak up about 120 billion tonnes.

This two-to-three billion tonne surplus makes the terrestrial plant kingdom a "net sink" for CO2 that removes up to 30 percent of human-generated carbon pollution from the air.

But there's a problem: when air temperatures climb, plants start to "exhale" extra CO2 with no change in the amount absorbed.

"All it would take is for global respiration to increase by three percent to shift the land surfaces from a 'sink' to a 'source'," Peter Reich, lead author of the study and a professor at the University of Minnesota, told AFP.

In a five year experiment, researchers set up heated environments for 1,200 trees of 10 North American species and were surprise
In a five year experiment, researchers set up heated environments for 1,200 trees of 10 North American species and were surprised to find that all 10 species adjusted to their new hotter conditions

Earlier experiments had shown that leafy trees exposed to a temperature increase of three-to-four degrees Celsius (5.4 to 7.2 degrees Fahrenheit) would quickly begin to pump out an additional 20 percent of or more.

Code-named 'B4Warmed'

In December, the world's nations agreed in Paris to hold the rise in to "well below 2.0C (3.6F)", but we are currently on track for an increase possibly twice that size by century's end.

Computer models used by climate scientists to project changes in greenhouse gas emissions "assume respiration"—the output of CO2—"increases over the long-term the same way it does over the course of a few hours," Reich said.

But nobody had bothered to verify if this was actually true.

To find out, Reich and colleagues set up a heated environment in the wild in 2009 for some 1,200 trees that included the 10 dominant North American temperate-zone species.

In an experiment—codenamed "B4Warmed"—lasting five years, they kept temperatures at 3.4C (6.1F) above seasonal averages.

To their surprise, the researchers discovered that—over the long haul—all 10 species acclimated, or adapted, to their new conditions.

Carbon dioxide output increased by only five percent rather than the 23 percent predicted under earlier models.

"Acclimation eliminated 80 percent of the increase," Reich said in an email exchange.

This suggests that "the associated increase in atmospheric CO2 concentrations from global warming may be much less than anticipated."

Though significant, this does not lessen the pressure to cut carbon pollution, he warned.

"The problem we created in the first place with our still exists."

Pierre Freidlingstein, a climate modelling expert at the University of Exeter in England, said the study did, indeed, show that leafy trees adjust to warming temperatures.

But he cautioned that the implications may be less important than advertised.

"This paper is not a game changer" when it comes to global warming, he said.

While Earth's living forests take up more CO2 than they give off, deforestation poses a double threat: Trees release stored-up CO2 when cut down and burned, and reducing the surface area covered by forests means fewer plants remain to absorb CO2.

An area of woodland twice the size of France has been lost to deforestation in the last 25 years, mainly to expanding agriculture and urbanisation.

Explore further: Climate 'carbon budget' soon maxed out: study

More information: Nature, nature.com/articles/doi:10.1038/nature17142

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Iochroma
1.1 / 5 (10) Mar 16, 2016
Terrestrial vegetation is really not the most significant biota compared to photosynthetic organisms in the seas; algas will likely accelerate carbon sequestration as seas warm. Even if corals die, algas will thrive.
baudrunner
1.3 / 5 (16) Mar 16, 2016
CO2 levels in the atmosphere have fluctuated since the earliest of prehistoric times. Massive wildfires, volcanic activity, and, in the present human activity, are all contributors. But, I maintain that the primary driver behind climate change is not human activity, but precession - that is, the wobble of the Earth as it turns on its axis. This wobble makes one complete rotation every 27,000 or so years, coinciding with the occurrence of the ice ages.

Further proof of this can be seen in the Arctic. Inuit elders have spoken before the U.N. on the subject of climate change. They say that the sun rises and sets in different places now than before, on the days of the winter and summer solstices. The elders all agree, they believe the Earth has shifted, wobbled or tilted to the North.

That is the primary driver behind climate change. It is unalterable.

http://www.thebig...ers.html
baudrunner
1.3 / 5 (13) Mar 16, 2016
If you still insist that human activity is to blame, then stop flying, if you want to help. Do a rough calculation in your mind concerning just how many cubic meters of oxygenated air that a single jet engine converts into CO2 and waste gases in just 1 second flying at 500 knots. Multiply that by the number of engines on a plane, and that by the number of planes in the air at any given time of day. In ONE second.

Feel guilty? You are.
Shootist
1.3 / 5 (12) Mar 16, 2016
The rubbish continues to fall down like rain.
axemaster
4.6 / 5 (14) Mar 16, 2016
But, I maintain that the primary driver behind climate change is not human activity, but precession... Inuit elders have spoken before the U.N. on the subject of climate change... Feel guilty? You are.

And I have a colleague who believes that Maxwell's Equations can be broken in macroscopic phenomena. We value quantitative analysis over feelings and anecdote because guess what, almost all humans fall way below the line that any reasonable person would call "stupidity".

"I maintain" or "I believe", when flying in the face of evidence and rational argument, usually translates to "I'm too dumb to know what I don't know". But please, break out the prayer crystals and go back to worshipping Donald Trump.

Also, I've set myself up so I don't have to fly, and I don't even have a car. I've also spent a lot of my personal time helping out climate change activist groups. So you can leave that noxious "moral superiority" of yours at home.

Worst part? You were actually serious.
leetennant
4.6 / 5 (11) Mar 16, 2016
This is a welcome addition to the little known area of plant respiration. People concentrate so much on their CO2 intake, they often ignore they also produce CO2 as well.
antigoracle
1.4 / 5 (11) Mar 16, 2016
"All it would take is for global respiration to increase by three percent to shift the land surfaces from a 'sink' to a 'source'," Peter Reich

REALLY??
So, plants will start burning more sugars than they produce?
szore88
1.3 / 5 (12) Mar 16, 2016
Carbon dioxide, considered the main vector for human-caused global warming, is 0.039% of the atmosphere- a trace gas. Water vapor varies, but averages around 1%, and is about ten times more effective a greenhouse gas than carbon dioxide. So water vapor is about 25 times more prevalent and ten times more effective; that makes it 250 times more important to the greenhouse effect than carbon dioxide. The TOTAL contribution of carbon dioxide to the greenhouse effect is therefore about 0.004%. The total human contribution to carbon dioxide since the start of the industrial revolution has been estimated at about 25%. So human greenhouse effect is a quarter of 0.00%, works out to about 0.001%. Since TOTAL greenhouse effect on temperature is estimated at around 63 degrees Fahrenheit, that would come to human-caused warming of about 0.063 degrees Fahrenheit.
Captain Stumpy
4.7 / 5 (12) Mar 16, 2016
CO2 levels in the atmosphere have fluctuated since the earliest of prehistoric times
@baud
ignoring the fact that we can actually tell natural from man-made sources of CO2 - consider this

... we can also show where we've historically been pummeled by large asteroids but that doesn't mean it would not be a problem for anyone else today, now, does it?

I mean... if we get a 10-15 km circumference asteroid headed for, say... Europe or the US... are you gonna say something like this?
"hey... it's not a big deal because obviously we had ancestors who survived Chicxulub! it's just nature! live with it! don't be such an alarmist! we can just move to..."
I maintain that the primary driver behind climate change is not human activity, but precession
you do know that this is studied and ruled out for a reason, right?
https://scholar.g...as_sdtp=

evidence trumps "i maintain"
antigoracle
1 / 5 (9) Mar 17, 2016
we had ancestors who survived Chicxulub

You mean... you are astonishingly stupid.
Captain Stumpy
4.6 / 5 (10) Mar 17, 2016
You mean... you are astonishingly stupid
@anti-intelligence
are you saying that you did not have a genetic tie to any survivor of the Chicxulub strike?

LMFAO

i guess that would explain a lot about you...
but i doubt that it is true unless you're a bot

of course, that would also explain a lot about you, considering the overwhelming stupidity of your typical post, like when you got caught lying, promoting fraud and intentionally altering your own graph because your dates wouldn't show the data you wanted it to
http://phys.org/n...mon.html

i mean... c'mon!

LMFAO
SamB
1.4 / 5 (10) Mar 17, 2016
Maybe plants won't boost global warming as much as feared but the alarmists will!
guyjohn123
1.4 / 5 (11) Mar 17, 2016
If you want to know what controls the weather on Earth, look up in the sky, it is called the Sun.

There is no man made global warning, it is the height of human arrogance to suggest otherwise and the general lack of understanding the scale and size of the Sun. The only thing that seems to rival the size of the Sun is the global warming proponents ego, it is blinding.

If you recall there was an Ice age 12000 years age, or glacial period.
The last glaciation centered on the huge ice sheets called ,the Laurentide Ice Sheet , was a massive sheet of ice that covered millions of square miles, including most of Canada and a large portion of the northern United States. It went away without any help from man. It was the Sun that sent the ice away.

guyjohn123
1.4 / 5 (10) Mar 17, 2016
You could line up 109 Earths across the face of the sun. About 1.3 million Earths could fit inside the sun. The sun contains 99.8 percent of the mass of the entire solar system. The mass of the sun is about 333,000 times the mass of the Earth, but do not let the facts get in the way. Yet we are told the little humans can take on the sun with their barbecues grills and wood burning stoves and effect the temperature? The fact is the earth has its own self adjusting system, we call it today's weather and the oceans. Satellite data has show no change in the overall average earth temperature. The newest and best way to determine global temperature is to use satellites to measure the temperature of the lower atmosphere, giving the Earth a uniform global sweep, oceans included, with no cities to create a false warming bias.
chileastro
3.2 / 5 (9) Mar 17, 2016
axemaster5 /5 (7) 21 hours ago
But, I maintain that the primary driver behind climate change is not human activity, but precession... Inuit elders have spoken before the U.N. on the subject of climate change... Feel guilty? You are.

And I have a colleague who believes that Maxwell's Equations can be broken in macroscopic phenomena. We value quantitative analysis over feelings and anecdote because guess what, almost all humans fall way below the line that any reasonable person would call "stupidity".


Amen, but it's beyond that. These assholes are proud of their ignorance. That's why so many are Americans; it's a cultural value there. Equal contempt for the good liberals that can't do what they have to do. Cultivate the garden. These weeds need to be culled and because you won't people will die. They've made it a choice; their useless lives or your kids'. They have the stomach to kill your kids; you don't to handle them.
antigoracle
1.7 / 5 (6) Mar 17, 2016
"I maintain" or "I believe", when flying in the face of evidence and rational argument, usually translates to "I'm too dumb to know what I don't know".
................

Also, I've set myself up so I don't have to fly, and I don't even have a car. I've also spent a lot of my personal time helping out climate change activist groups.

The very definition of the idiot is that they are incapable of identifying what they are. You did not even have to read the article, but just glance at the headline to know that the doom and gloom you "believe" is not happening and yet you "maintain" your ignorance.
Let us know when you move into that cave and start living of the land. Don't forget to invite your "climate change activist groups" along, let's see how many will join you.
Captain Stumpy
4.3 / 5 (6) Mar 17, 2016
The very definition of the idiot is that they are incapable of identifying what they are

perfectly demonstrated by antig here:
http://phys.org/n...mon.html

baudrunner
1.7 / 5 (6) Mar 17, 2016
evidence trumps "i maintain"
Stumpy, you're so narrow-minded and prejudiced that you formulate your critique before you have even understood what is being said. I said, the Inuit elders report that the sun rises and sets in different places than it has historically. That this change has become noticeable to the extent that they have raised the alarm.

Keep believing your "scientist" friends. They are more plentiful than fresh water in America. Schools churn them out like hamburger. The subject of truth had no place in their curriculum.
greenonions
4.4 / 5 (7) Mar 18, 2016
baudrunner
The subject of truth had no place in their curriculum.
Actually - it was kind of central to their curriculum.
Captain Stumpy
4.4 / 5 (7) Mar 18, 2016
Keep believing your "scientist" friends
@baud
yeah... i will, because evidence
Schools churn them out like hamburger.
and yet we still have a shortage
The subject of truth had no place in their curriculum.
as Green notes, it is central to the curriculum

it's too bad that you missed getting an education... you might have been able to learn something
Eddy Courant
1.7 / 5 (6) Mar 18, 2016
I'm so scared of CO2 now that I can't sleep at night. When will this horror end? ;-)
Phys1
4.4 / 5 (7) Mar 18, 2016
I'm so scared of CO2 now that I can't sleep at night. When will this horror end? ;-)

When you take your medication.
Da Schneib
5 / 5 (4) Mar 20, 2016
Terrestrial vegetation is really not the most significant biota compared to photosynthetic organisms in the seas; algas will likely accelerate carbon sequestration as seas warm. Even if corals die, algas will thrive.
Yeah, more red tides. Neato.

NOT.
Da Schneib
5 / 5 (5) Mar 20, 2016
There is no man made global warning, it is the height of human arrogance to suggest otherwise and the general lack of understanding the scale and size of the Sun.
Suggesting that the composition of the atmosphere doesn't affect the temperature of Earth's surface is unutterably stupid. It's like suggesting that you won't be warmer if you cover yourself with a tent.

Duh.
Da Schneib
5 / 5 (3) Mar 20, 2016
Amen, but it's beyond that. These assholes are proud of their ignorance. That's why so many are Americans; it's a cultural value there. Equal contempt for the good liberals that can't do what they have to do. Cultivate the garden. These weeds need to be culled and because you won't people will die. They've made it a choice; their useless lives or your kids'. They have the stomach to kill your kids; you don't to handle them.
What you're suggesting is despicable.

Your "culling" is killing people. I hate them, but sorry I'm not down with killing them. I'm going with making them look so stupid they have no choice but to admit they screwed up. It's the slower but surer course. The ones who will never admit it will eventually all die off and good riddance; meanwhile most of us are buying hybrid cars and solar energy.

Get over it.
Da Schneib
5 / 5 (3) Mar 20, 2016
The subject of truth had no place in their curriculum.
Truth is refrigerators and transistors and jet aircraft. Science *works*. Denying science isn't "truth." It's denial of truth.

Get over it.
BackBurner
2 / 5 (4) Mar 21, 2016
Earth's plants and soil microbes absorb and exude huge quantities of heat-trapping CO2, the main driver of global warming.


Less than ten sentences into the article, the above appeared. I undermines the author's credibility almost completely. Why does this happen?

Carbon Dioxide isn't the "main driver" of Global Warming. That's very well understood. This site purports to be a source of information on physics and the advancement of physics, but publishes an article with this sentence? How could this happen?
greenonions
5 / 5 (3) Mar 21, 2016
Well Backburner - I guess you could parse out the word driver - and make an argument that the Sun is the "driver' of global warming. The sentence you highlight - seems to me pretty compatible with this kind of statement - from the science community -
The Intergovernmental Panel on Climate Change (IPCC) reported in 2014 that scientists were more than 95% certain that global warming is mostly being caused by increasing concentrations of greenhouse gases (GHG) and other human (anthropogenic) activities
From - https://en.wikipe..._warming It certainly does not seem to me that your outrage over the printing of this sentence is too proportionate.
leetennant
5 / 5 (3) Mar 22, 2016
Carbon dioxide may not be the 'main driver' of climatic changes generally but it is definitely the main driver of the current climatic changes we're seeing. Otherwise known as "the entire damn point".
barakn
3 / 5 (2) Apr 04, 2016
Carbon dioxide, considered the main vector for human-caused global warming, is 0.039% of the atmosphere- a trace gas. Water vapor varies, but averages around 1%, and is about ten times more effective a greenhouse gas than carbon dioxide. So water vapor is about 25 times more prevalent and ten times more effective; that makes it 250 times more important to the greenhouse effect than carbon dioxide. - szore88.
I suppose, as long as you are going to ignore the fact that by a simple phase change, water vapor turns into clouds, which reflect sunlight away from the planet. Is there some specific reason you are ignoring clouds, like maybe they don't fit into your preconceived notions?
baudrunner
1 / 5 (1) Apr 08, 2016
and yet we still have a shortage
Yes!! a shortage of qualified and intelligent scientists, in spite of the fact that the schools are "churning them out like hamburger". You've just vindicated my point, Stumpy.

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