Forests in the Eastern United States are growing faster than they have in the past 225 years

From the Smithsonian Environmental Research Center blog:

“The chief culprit appears to be climate change, more specifically, the rising levels of atmospheric CO2, higher temperatures and longer growing seasons.”

This jibes well with what NASA has been seeing globally via satellite measurements:

Surprise: Earths’ Biosphere is Booming, Satellite Data Suggests CO2 the Cause

And what has been found by the University of Wisconsin in Madison:

Greenhouse gas carbon dioxide ramps up aspen growth

Here’s the full report from the Smithsonian:

Forests are growing faster, climate change appears to driving accelerated growth

Speed is not a word typically associated with trees; they can take centuries to grow. However, a new study to be published the week of Feb. 1 in the Proceedings of the National Academy of Sciences has found evidence that forests in the Eastern United States are growing faster than they have in the past 225 years. The study offers a rare look at how an ecosystem is responding to climate change.

SERC woods during wintertime

Liriodendron tulipifera, or tulip poplar, is a common tree in the temperate forests surrounding the Smithsonian Environmental Research Center. Other species include sweetgum, American beech, and southern red oak. Photo: Kirsten Bauer.

For more than 20 years forest ecologist Geoffrey Parker has tracked the growth of 55 stands of mixed hardwood forest plots in Maryland. The plots range in size, and some are as large as 2 acres. Parker’s research is based at the Smithsonian Environmental Research Center, 26 miles east of the nation’s capital.

Parker’s tree censuses have revealed that the forest is packing on weight at a much faster rate than expected. He and Smithsonian Tropical Research Institute postdoctoral fellow Sean McMahon discovered that, on average, the forest is growing an additional 2 tons per acre annually. That is the equivalent of a tree with a diameter of 2 feet sprouting up over a year.

Parker measuring a tree.Forest ecologist Jess Parker began his tree censuses his first day on the job: September 8, 1987. Photo: Kirsten Bauer.

Forests and their soils store the majority of the Earth’s terrestrial carbon stock. Small changes in their growth rate can have significant ramifications in weather patterns, nutrient cycles, climate change and biodiversity. Exactly how these systems will be affected remains to be studied.

Parker and McMahon’s paper focuses on the drivers of the accelerated tree growth. The chief culprit appears to be climate change, more specifically, the rising levels of atmospheric CO2, higher temperatures and longer growing seasons.

Assessing how a forest is changing is no easy task. Forest ecologists know that the trees they study will most likely outlive them. One way they compensate for this is by creating a “chronosequence”—a series of forests plots of the same type that are at different developmental stages. At SERC, Parker meticulously tracks the growth of trees in stands that range from 5 to 225 years old. This allowed Parker and McMahon to verify that there was accelerated growth in forest stands young and old. More than 90% of the stands grew two to four times faster than predicted from the baseline chronosequence.

Two trees tagged with a metal band and an orange ribbon.Parker, his colleagues and a team of citizen scientists have tagged more than 20,000 trees at the Smithsonian Environmental Research Center. Photo: Kirsten Bauer.

By grouping the forest stands by age, McMahon and Parker were also able to determine that the faster growth is a recent phenomenon. If the forest stands had been growing this quickly their entire lives, they would be much larger than they are.

Parker estimates that among himself, his colleague Dawn Miller and a cadre of citizen scientists, they have taken a quarter of a million measurements over the years. Parker began his tree census work Sept. 8, 1987—his first day on the job. He measures all trees that are 2 centimeters or more in diameter. He also identifies the species, marks the tree’s coordinates and notes if it is dead or alive.

By knowing the species and diameter, McMahon is able to calculate the biomass of a tree. He specializes in the data-analysis side of forest ecology. “Walking in the woods helps, but so does looking at the numbers,” said McMahon. He analyzed Parker’s tree censuses but was hungry for more data.

Parker holding the diameter tape he uses to measure the trees.Parker uses diameter tape or ‘d-tape’ to measure the trees. The tape is calibrated to convert the tree’s circumference, the measurement used to determine a tree’s biomass. Photo: Kirsten Bauer.

It was not enough to document the faster growth rate; Parker and McMahon wanted to know why it might be happening. “We made a list of reasons these forests could be growing faster and then ruled half of them out,” said Parker. The ones that remained included increased temperature, a longer growing season and increased levels of atmospheric CO2.

During the past 22 years CO2 levels at SERC have risen 12%, the mean temperature has increased by nearly three-tenths of a degree and the growing season has lengthened by 7.8 days. The trees now have more CO2 and an extra week to put on weight. Parker and McMahon suggest that a combination of these three factors has caused the forest’s accelerated biomass gain.

Ecosystem responses are one of the major uncertainties in predicting the effects of climate change. Parker thinks there is every reason to believe his study sites are representative of the Eastern deciduous forest, the regional ecosystem that surrounds many of the population centers on the East Coast. He and McMahon hope other forest ecologists will examine data from their own tree censuses to help determine how widespread the phenomenon is.

These findings are also important for policymakers trying to address climate change. Future carbon cap-and-trade rules will need to quantify the amount of carbon forests hold. If faster growth rates prove the norm, this could affect the formulas and the dollar value assigned to forests that are cut or conserved.

Parker and McMahon don’t expect SERC’s forest to continue growing at this accelerated rate forever. Some day the growth rate will level off. When that happens, they wonder how that will affect CO2 levels. If trees are sponges that absorb CO2, what will happen to CO2 levels in the atmosphere when the trees become saturated? It’s a question for further exploration. In the meantime, Parker will continue walking through the SERC woods, tape measure in hand carefully tracking the growth of the trees.

PNAS will make the study available online sometime this week at this link:


newest oldest most voted
Notify of

“the mean temperature has increased by nearly three-tenths of a degree ”
UHI. SERC is about 10-12 miles from Baltimore and Washington DC.

Trees become saturated? Let’s see, if that happens they die, fall to the ground and new trees sprout up… Can we all sing “Circle of Life” now?


Anyone with allergies or knowledge of Claritin sales should be able to attest to this.

Van Grungy

Vegans of the world rejoice!!!
Climate Change is good for granola crunchers!!!


“The chief culprit appears to be climate change, more specifically, the rising levels of atmospheric CO2, higher temperatures and longer growing seasons.”
Since when is faster tree growth a crime or misdeed perpetrated by a “culprit”.


So, his little grove is growing faster than usual, so it has to be globable warming caused by man and soon disaster will strike when the trees become saturated with co2. It is always the same with liberals and these types-worried about something and the disasters ahead. They need what one commenter said in a previous post;”They need a wee dram of scotch and relax”.
Well, Parker will continue walking through the woods with his tape measure and his head up his….

Allen Cichanski

Could someone explain to me why more extensive and healthier forests are a bad thing? Given all the climategate stuff we now know, why is anyone with a single functioning brain cell still worrying about “climate change” or carbon dioxide as a pollutant? Its plant food guys and the plants are responding to a better diet.

Steve Goddard

In 2009, the US had the third coldest October on record after having the 36th coolest April on record.
How does that translate to a lengthening growing season?


Umm, then why is there a “divergence problem”?


. . .requiring that some people need to “hide the decline”?

OOps Global


Quick! We must act to stop the unchecked overgrowth of the Appalachians! We must have the EPA classify CO2 as a pollutant and ban it’s release into the atmosphere so that everyone on the east coast doesn’t end up paying thousands more per year in gardening costs!!

From the article: The chief culprit appears to be climate change, more specifically, the rising levels of atmospheric CO2, higher temperatures and longer growing seasons.
Rising levels of C02: check
Higher Temperatures: check
Longer Growing Season: check


The east coast has been relatively warm for the last decade because of local weather. Compare tree growth in the upper plains that have had a more typical growing season. I’ll bet they show marginal change.

Tom G(ologist)

Seems to contradict the idea that man-made CO2 lingers in the atmosphere for hundreds of years, doesn’t it?


Which leaves me wondering two things:
1. How is this bad?
2. How is this any different from what “we” have been saying: CO2 rises, biomass takes it out, thus eliminating the ridiculous concept of a “tipping point”.
CO2 is plant food. This is hardly “new science”.


“When that happens, they wonder how that will affect CO2 levels. If trees are sponges that absorb CO2, what will happen to CO2 levels in the atmosphere when the trees become saturated? It’s a question for further exploration.”
They should come and visit the West Coast… trees can grow quite big if given enough nutrients, water and CO2. Also, a great deal of that “stored” carbon falls every fall… with the leaves!!!
Of course, as they stated, they need more time and money to study this more… typical!
Tree growth is a sure good example of positive CO2 feedback.


And – what about the “hidden” decline of M. Mann’s tree rings? How was that possible? What happened there?


Why not to create special recreation camps with lots of green and put into them all these mad greenies?, of course conveniently medicated to avoid their brain temperature to increase. There we could also install a train for JH et al.. That will be cheaper than Cap&Trade, so the rest of us could return to the glorious years of development and richness, and live joyful, peaceful and productive lives.


Wait a minute… (small spark in my head)… if the trees grow better and are healthier with more carbon dioxide and warmer weather, then our crops and vegetables will also grow better….. Oh crap… it also means that if we try to reduce CO2 in the atmosphere and it gets colder, then we will all starve to death.

Robert L

They are throwing him under the bus!


What bunch of crap. CO2 is the main reason why plant growth has accelerated. This article is trying to link accelerated plant growth(symptom of higher CO2) as proof of global warming.

Higher levels of CO2 in the atmosphere helps plants and trees grow faster?
Who’d a thunk it?


Stephan (13:34:28) :
can’t believe it
Monbiot’s tactic seems to be similar to fighting gangrene: to hack out obvious diseased flesh – Jones and the hapless PR suit at CRU in this instance – while insisting that the rest of the body of AGW can survive.
Looks like he’ll keep on hacking off bits and insisting that AGW is healthy as long as there is still a wriggling amoeba-sized blob of AGW left.


“Stephan (13:34:28) :
can’t believe it

Must be written by the OTHER George Monbiot. They must have two of them.

I think whoever popularized the article must’ve misunderstood what the ecologist was saying about growth topping out.
Probably the ecologist said either that “the growth of those specific stands would top out as they got older” or that “the growth _rate_ of those type of trees would top out at a stable but high level.”
I can’t imagine that increasing CO2 content and longer seasons would mysteriously stop causing accelerated growth at some point – maybe if it got so hot that they became water limited.


Good Lord, here we go again.
That little “normal” line in the middle
Things can’t change, even when it’s proven that it was bad before,
and the change was for the better.

dave ward

Just read in the local paper that there is to be a free event next week at the John Innes Centre, Norwich (just over the road from the UEA). It is to be introduced by science operations manager Steve Rawsthorne, followed by talks both by the centre’s own scientists, and those from the Sainsbury Laboratory, who are at the forefront of combating the global challenge of food security. The subject is how to increase food production to cope with the UN projected 50% rise in world population by 2050. I hope they realise that increased CO2 concentrations will help achieve that aim……..

James Sexton

So, the Amazon jungle might benefit from the increase in CO2????? NO way!! Dude, someone needs to let Pachauri know they got it backwards!!!!!

Veronica (England)

I’ve just had a great idea for a carbon sequestration method. Store it in trees!


This is in conformity with 2 earlier studies. One that showed similar growth in all biologics in the tundra. And likewise in tropics. While this was exclusively on trees, it would be interesting to see if fauna also increased as it did in the other regions.


two of the following pieces appear in a group on google news, but don’t appear once u expand the group:
Press Trust of India: Pachauri rejects findings on peaks based on essay
“The allegations (that the finding was based on an essay by a student and an article in a magazine) are totally unfounded and baseless. I maintain that the IPCC monitoring systems are still robust and solid,” Pachauri told PTI.
The IPCC credibility has come under attack in the past few days for picking a report that Himalayan glaciers will melt by 2035 from a science magazine without peer-reviewing it, a fault later admitted and regretted by the climate body.
“Yes, there was only this error which we accepted and corrected as well when it was brought to our notice.
India Times: TERI: Allegations against Pachauri not fair
After repeated attacks on the ‘faults’ in the Intergovernmental Panel on Climate Change (IPCC) report, the latest being observed reductions in mountain ice in the Andes, Alps and Africa due to global warming, the Tata Energy Research Institute, headed by IPCC panel chairman Dr R K Pachauri, has reacted to the ongoing flurry of scandals that have enveloped the beleagured scientist.
Dr. Arabinda Mishra, Director-Climate Change at Centre for Global Environment Research,TERI said that while he would not like to comment on the IPCC issue, the IPCC itself was an organisation of “robust scientific inquiry” and that there was consensus about climate change being a legitimate problem. He added that the allegations against Pachauri were unfair.
“I would not like to comment on that. Because that is about IPCC and we known that IPCC is a body with robust processes of scientific enquiry and we also know that IPCC has come out with a retraction, so we know that the larger picture still holds valid, the greater scientific consensus is still there that you have a problem in the form of climate change,” said Mishra on Tuesday (February 2) to TIMES NOW.
India Times: ‘IPCC used my thesis for glacier report’
A day after bringing you a story on the Intergovernmental Panel on Climate Change (IPCC) report on the meltdown of glaciers being based on a university thesis, TIMES NOW has tracked the student of the infamous essay that leaves the UN climate change panel chairman Rajendra Pachauri cornered.
NOTE below: not a mention about Dario being funded by UNEP.
India Times: Dario-Andri Schworer whose thesis at the University of Berne has been been quoted as a source of the recent IPCC report on melting mountain ice in various regions of the world, said the IPCC had used some parts of his thesis in formulating their report and also said that his report had in fact nothing to do with the Himalayan glaciers. ..
Schoworer’s dissertation was titled ‘An Inquiry into Possible Effects of Climatic Change on the Mountain Guide Trade in the Bernina Region’.
The dissertation quotes observations from interviews with around 80 mountain guides in the Bernina region of the Swiss Alps. The problem with using the data in his thesis to predict glacier meltdown is that it is unscientific. Loss of ice cited by climbers are a poor indicator of a reduction in mountain ice. TIMES NOW also wonders, whether Pachauri aware of the panel lifting information from student’s thesis, and why Dari took so many years to speak out? Could someone in the IPCC have prevailed upon him to keep quiet?
Dari admitted in his interview to TIMES NOW that it was possible that the IPCC report had errors but added that the issue was “a mess in the media”.
‘My thesis was about glaciers and mountains in the Swiss Alps,” said Dari. “The IPCC has very strong standards in controlling the report, and the Swiss university where I have done the thesis also has very strong rules and standards. The problem is people at the The Telegraph have not done enough research before they issued the article. Because I have had a phone call (from the paper) only recently, and sure enough he did not call me back to see all the data of this thesis. So in fact the data from this thesis is of a high standard and has nothing to do with the Himalayan glaciers, it’s about the Swiss Alps and the interaction of climate change on mountain-guiding,” explained Dari.
What is notable is that the researcher’s dissertation itself is not entirely about climate change. In fact, he mentions the number one reason that mountain guides give for decreased climbs is not climate change, but “…the recession and the high exchange rate of the Swiss franc in relation to the German mark. In the second place they mention changes of the natural environment.”
The thesis states that about half of the guides interviewed were not even sure that the weather had gotten worse: “For about half of the mountain guides it was not clear, whether extreme wheather conditions which affect the demand for mountain guides negatively, have been occuring more often in the last few years.”
Ironically the work references the IPCC twice, mainly on predictions of future climate scenarios: “Based on the climate scenarios of the IPCC, permafrost and glacier shrinkage scenarios suggest that these changes will continue and probably even accelerate in the future.”
However the thesis concludes ambiguously, saying among other things: “In how far the changes observed indicate a global change of climate can only be guessed and will show in the future.”
Schworer says this doesn’t mean the IPCC report which quotes from his work, is totally flawed.
“First of all you have to know that this report is huge and there are so many researchers and scientists from all over the world participating in this report. And all these researchers and scientists are highly accredited, working hard to come to their conclusions and are of high standards. When you’re working on a new job sometimes you may make a mistake. I don’t know enough about the context of the mistake you are talking about at the moment, but I think it is a little bit cheap or sad, when you find from there a paragrpah that may be not very well researched, and then you say the whole report is not good enough… I hardly can believe that the mistake in the IPCC report is a big issue because when you see the standards the IPCC has I think it is not very relevant,” said Schworer.
He said, “You have to understand that a lot of my effort and energy has gone into this expedition where we tried to inspire young children to do someting for our climate. I am actually not very familiar with the IPCC report. The only thing is I was asked if they can use some data from my thesis to complete their report, that was in 2006 – and I was happy to contribute this data because it took a lot of work for me to generate my conclusions and thesis. The political questions I am really not the right person to give an answer to . I am a just researcher,” he concluded.
Dari is not alone in his defence of climate change theorists and the IPCC’s conclusions; last week, scientists from around the world voiced their solidarity with IPCC, insisting that despite the errors – which they said were minor – the science in the IPCC report was sound and the conclusion of the report unchallenged.
Meanwhile, after repeatedly being dragged in the eye of the storm for the ‘faults’ in the Intergovernmental Panel on Climate Change (IPCC) report, the veteran scientist Pachauri on Monday (February 1)dismissed fresh attacks as ‘totally unfounded and baseless’ and maintained that the IPCC monitoring systems are still robust and solid.
“While the media has been quick to castigate the IPCC report, most of the scientist fraternity from across the world has spoken in support of Dr Pachauri. That’s a clear indication that his work is still highly regarded,” said a source working closely with Pachauri. ..

Harold Blue Tooth

Steve Goddard (13:35:57) :
How does that translate to a lengthening growing season?
I was going to make a similar point. You beat me to it.

D. King

Hey Hey, Ho Ho, free the carbon and trees will grow.
Hey Hey, Ho Ho…

George E. Smith

Well it’s the new free clean green renewable fossil free energy program being promoted by the Obama Administration.
We grow the trees faster, then cut them down and burn them in our fireplaces for warmth and for making stew.
Then we replant them, and the soot from our chimneys makes aerosols that makes it rain to lubricate the next generation of fast growing trees.


Did we mean, “jibes”?
Although “jives” is more entertaining…

Harold Blue Tooth

rbroberg (13:38:05) :
Rising levels of C02: check
Higher Temperatures: check
Longer Growing Season: check

You need a reality ‘check’.
In the real world growing seasons are shorter. Have a talk with a farmer.
And there has been no warming for 15 years. There has been clear cooling for 5 years. You need to ‘check’ the data.
But I think you may come back with James Hansen’s data set of warming. Are you going to cherry pick like that? Are you going to cherry pick what was extensively cherry picked?

PaulH from Scotland

More UK Carbon Taxation.
From Richard North at EUReferendum…
“Amid the torrent of “climate change” news, we missed this one, the government’s very own “cap and trade” scam, disarmingly labelled the CRC Energy Efficiency Scheme – formerly the Carbon Reduction Commitment.”
Sneaky buggers.


The rate of sequestration varies over the life of the species of tree. Larger trees tend to make more wood per year than smaller trees. The rate of growth starts low, peaks at 10 to 70 years and then slowly declines (depending on the species).
The trees in the pictures look young. Liriodendron tulipifera can grow to over 160 feet and are a fast growing species.
Was this study done based solely on Parker’s data and is it based on the species in relation to normal growth? Looks like another study that was done over a short a period of time without peer review?

David Alan Evans

jack morrow (13:36:50) :

OOps Global

Nope, you just misspelt globabble! 😉
What I can’t figure is, this guys forest is thriving…
& That’s a disaster?
Someone remind me why all this climate change is bad please.

Harold Blue Tooth

Veronica (England) (13:56:22) :
I’ve just had a great idea for a carbon sequestration method. Store it in trees!
Very good idea Veronica. But I think God had that idea first. 🙂

R. Craigen

The last paragraph contains stupidity on the verge of insight: What to do, indeed, when the absorption of carbon levels off?
Well … if the ultimate goal is to absorb carbon, the answer is pretty obvious, except apparently to the Smithsonians: Cut down the damn trees!
And plant new ones, that is.
Mature (at the “old-growth” end of the scale) forests, as they observe, are close to carbon-neutral. Young forests are effective carbon sinks. If you want to moderate CO2 increase, then cut the mature stands and replace them with new forests.
In other words, silviculture, as it has been practiced in North America now for decades, is the optimal strategy for carbon sequestration using forests. You needn’t feel guilt cutting down all those old trees. If CO2 is “bad” (something I reject, but, let’s just say perhaps there’s something such as too much of a good thing here) then cut down the damn trees and get new ones growing in their place. Process that wood into lumber and paper (just burning it returns the CO2 to the atmosphere, so I suppose we want to avoid that).
Obviously you don’t want to cut them all down at once. Start with the old growth, with selective clear-cuts, and manage the introduction of new forests to optimize growth at a constant rate. Just like our lumber management experts have known for ages.
If you REALLY love the earth and REALLY believe that this needs we must maximize sequestration, then open up logging for the protected old-growth forests that are no longer absorbing carbon. Lets see Greenpeace and WWF field that one! It’s a no-brainer that this would be a boon to the health of the biosphere. But I really doubt some of those guys have any love for mother earth, only for a romantic notion of some pristine childhood fantasy of a pristine, mystical eden where nature is God and stepping on a blade of grass is an unspeakable crime.

Harold Blue Tooth

D. King (14:08:25) :
Hey Hey, Ho Ho, free the carbon and trees will grow.
Hey Hey, Ho Ho…

LOL! Are you from Berkeley?

Lee Klinger

“Ecosystem responses are one of the major uncertainties in predicting the effects of climate change.”
I couldn’t agree more. Last evening I gave a seminar at the University of California at Santa Barbara on Gaia theory and climate change. Thanks, Anthony, for giving me plenty of fodder for a critical examination of global warming issues. Details of the talk can be found here:

It’s worse than we thought

Harold Blue Tooth

David Alan Evans (14:14:49) :
Someone remind me why all this climate change is bad please
When you want to use it as a means to getting grant money. 😉


This just in: The pope’s Catholic.

The death of global warming: click

Harold Blue Tooth

When I see these kind of stories it always reminds of Michael Crichton’s lecture on how man screws up nature when he does something he thinks will improve upon it.
53 minute Michael Crichton video