For decades, we’ve been warned that the Amazon rainforest—the so-called “lungs of the planet”—was on the verge of collapse. Headlines screamed about tipping points, mass die-offs of giant trees, and irreversible climate catastrophe. Yet, buried in the data, something rather inconvenient has been happening: the Amazon is getting bigger, fatter, and taller.
A new Nature Plants study, covering 30 years of field data from 188 permanent forest plots across Amazonia, shows that the average size of Amazon trees has increased by more than 3% per decade . In plain English: the forest isn’t shrinking in stature, it’s bulking up.
The researchers found:
- Mean tree size up 3.3% per decade
- Largest trees (>40 cm diameter) increased 6.6% per decade
- Biomass increasingly concentrated in the biggest trees
- No evidence of large-scale die-off from climate stress
In their words:
“We find that tree size has been increasing across all size classes… The observed patterns match the expectations from increased resource availability, particularly from rising atmospheric CO₂.”
So much for the “large trees are doomed” hypothesis.
This is the CO₂ fertilization effect in action. The key driver, according to the authors, is not some vague “forest resilience” or a miraculous recovery from past disturbance, but rather plain old plant biology: more carbon dioxide in the air means more raw material for photosynthesis.
CO₂ fertilization is no longer a theory tested only in labs. This study confirms it at continental scale: Amazon forests are thriving, not suffering, in a world with more CO₂ .
- Big trees: with better access to light, they are expanding even faster, locking away more carbon.
- Small trees: surprisingly, they’re also benefiting. With extra CO₂, understory trees living on the edge of survival at low light can now photosynthesize more efficiently and survive longer .
The result is a forest with both fatter giants and healthier smaller trees—something alarmist models didn’t predict.
News Coverage: A Rare Dose of Optimism; even the mainstream outlets couldn’t spin this entirely negative.
- Phys.org summarized it as a “good news story,” noting that “the trees in intact forests have grown bigger; even the largest trees have continued to thrive despite these threats”.
- NBC News ran with: “Giant trees of the Amazon get taller as forests fatten up on carbon dioxide”, pointing out that “We’re not seeing signs of them dying off… They are increasing in size and number as well”.
- LiveScience said: Trees of all sizes across the Amazon rainforest are getting fatter due to climate change, a new study shows.
Of course, both outlets quickly hedged: warnings about future drought, deforestation, lightning, and the ever-present “tipping point” were sprinkled throughout. But the underlying data tells a different story: rising CO₂ is currently a net positive for the Amazon’s forests.
We’ve been told endlessly that rising CO₂ is a global disaster, turning forests into tinderboxes and deserts. Yet the Amazon—supposedly one of the most climate-sensitive ecosystems—appears to be doing the opposite: absorbing more carbon, producing more biomass, and thriving.
This doesn’t mean the Amazon is invulnerable. Deforestation is still a real threat (chainsaws trump CO₂), but the oft-repeated claim that climate change alone is killing the forest doesn’t stand up to scrutiny.
My Final Thoughts
The real takeaway is this:
- Rising CO₂ is not just a “pollutant”—it is also a powerful plant fertilizer.
- Amazonian forests are currently benefitting, not suffering, from this change.
- Predictions of imminent collapse have once again run headlong into inconvenient data.
When climate modelers assure us that “the science is settled,” it’s worth recalling just how often field data overturns the narrative. The Amazon was supposed to be collapsing. Instead, its trees are thriving.
That doesn’t sell headlines or funding proposals, but it’s what the evidence shows.
So, next time someone calls CO₂ “pollution,” remind them: without it, plants—and by extension, we—wouldn’t exist. And with a bit more of it, the world’s largest rainforest seems to be doing just fine.
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If trees pack their trunks, then they might be leaving.
They are branching out into the world.
6th grade biology (from 45 years ago) FTW!
Well back then they taught science, not ideology.
Unless the COP meeting chops it down.
But a basic premise of The Green Blob is that any change, especially human caused, is a Bad Thing. They will find some rationale why more biomass in the Amazon is actually bad, and we really need to flog ourselves, or try for Net Zero, whichever hurts more.
Yeah they tried that with cereal grains. Production is up but nutrition per pound is down. But we still wind up with waaay more nutrition right? No answer.
The argument doesn’t xfer well to trees. Yes there’s more wood, thicker wood, taller wood, but its not good wood. Well if the wood is no good, how does it grow thicker and taller? Viagra?
Enhanced atmospheric CO2 has never been a “problem” of any sort.
It is TOTALLY BENEFICIAL to the whole planet.
Climate Emergency !!!! Amazon trees are becoming OBESE !! 😉
Too funny. 😉
While the Amazon may produce 75% of the O2 produced by terrestrial plants.
However the ocean produce about 75% of all the O2 produced by green plants.
The reality is that the Amazon produces 75% of 25% or less than 19% of all O2 generated.
Beyond that, if the Amazon forest does die away, it will be replaced by grasses, bushes and smaller trees. While the total amount of O2 generated will probably not be as great as what the Amazon generated, but it won’t go to zero either.
Sahara used to be the rain forest and Amazon the desert. People forget.
The Amazon rainforest has been around for the past 50,000,000 years. At the time of its origin, CO2 levels were about 2,000 ppm.
Hold on. What about all the Lidar evidence of dense cultivation in Amazonia?
https://en.wikipedia.org/wiki/Pre-Columbian_agriculture_in_the_Amazon_Basin
Very nice. If CO2 were the dangerous gas we are told it is it would be easy to show it using proper science. All of these contradictions and contrary results would have been dealt with decades ago. CO2 can’t cause catastrophic global warming, stop saying that it can. One more thing CO2 is the only thing we should be talking about all this nonsense about climate change and net zero is a bunch of hogwash.
We need to put those fat trees on a diet. They are taking nutrients from the Third World. /S if needed
The issue in Amazonia is widespread clearance, not how the trees which remain are doing. There’s no trees at all where the ranchers felled them all, then moved the cattle in.
Actually the issue has been clearing trees for farms. However once the farmers moved out, the trees came back.
Have to take umbrage with your wording where you say.. “Rising CO₂ is not just a “pollutant””
Should be… “Rising CO₂ is not even a “pollutant”
Trouble is that a thriving Amazon ups the atmospheric water vapour (which is is probably the driver of adverse statistics).
Every silver lining has a cloud!
By definition is usually added to that. 🙂
The notion that CO2 is a ‘pollutant’ is bordering on blasphemous. Without CO2 no life. What it therefore basically says is that life itself is a ‘pollutant’. The originators of that nonsense ought to be put to the stake?
The Population Bomb.
And Amazon Rainforest is based too on winds from the east with desert particulates from Africa fertilizing the region.
“Rising CO₂ is not just a “pollutant”—it is also a powerful plant fertilizer.”
Anthony: I know you didn’t mean it but this sentence states that CO2 is a pollutant. I suggest removing the words “just” and “also”.
Many thanks for all the great work you do.
Chris Wright (not the famous one!)
Same applies to every leaf and blade of grass on the planet.
our emissions get absorbed locally very quickly.
Long term trends are ocean driven.
I’m concerned about the cardiovascular disease that could cause these fatter trees to suffer more heart attacks, strokes, and other serious health issues related to increased girth.
No worries, we’ll just carpet bomb the Amazon with statins. 🤣
😎
On the other hand, CO2 seems to be the cure for “The Earth’s Lungs” COPD.
Let’s ditch the misinformation:
“the trees in intact forests have grown bigger; even the largest trees are thriving with higher CO2 levels”.
THERE ARE NO “threats.”
Please stop repeating their misinformation.
FIFY
So another growing sink for atmospheric CO2 not fully accounted for in the models, I presume.
Lots of things even AIs don’t and can’t know.
This is old. The context was weather forecast models and climate forecast models.
“http://wattsupwiththat.com/2012/05/12/tisdale-an-unsent-memo-to-james-hansen/#comment-985181
Gunga Din says:
May 14, 2012 at 1:21 pm
joeldshore says:
May 13, 2012 at 6:10 pm
Gunga Din: The point is that there is a very specific reason involving the type of mathematical problem it is as to why weather forecasts diverge from reality. And, the same does not apply to predicting the future climate in response to changes in forcings. It does not mean such predictions are easy or not without significant uncertainties, but the uncertainties are of a different and less severe type than you face in the weather case.
As for me, I would rather hedge my bets on the idea that most of the scientists are right than make a bet that most of the scientists are wrong and a very few scientists plus lots of the ideologues at Heartland and other think-tanks are right…But, then, that is because I trust the scientific process more than I trust right-wing ideological extremism to provide the best scientific information.
=========================================================
What will the price of tea in China be each year for the next 100 years? If Chinese farmers plant less tea, will the replacement crop use more or less CO2? What values would represent those variables? Does salt water sequester or release more or less CO2 than freshwater? If the icecaps melt and increase the volume of saltwater, what effect will that have year by year on CO2? If nations build more dams for drinking water and hydropower, how will that impact CO2? What about the loss of dry land? What values do you give to those variables? If a tree falls in the woods allowing more growth on the forest floor, do the ground plants have a greater or lesser impact on CO2? How many trees will fall in the next 100 years? Values, please. Will the UK continue to pour milk down the drain? How much milk do other countries pour down the drain? What if they pour it on the ground instead? Does it make a difference if we’re talking cow milk or goat milk? Does putting scraps of cheese down the garbage disposal have a greater or lesser impact than putting in the trash or composting it? Will Iran try to nuke Israel? Pakistan India? India Pakistan? North Korea South Korea? In the next 100 years what other nations might obtain nukes and launch? Your formula will need values. How many volcanoes will erupt? How large will those eruptions be? How many new ones will develop and erupt? Undersea vents? What effect will they all have year by year? We need numbers for all these things. Will the predicted “extreme weather” events kill many people? What impact will the erasure of those carbon footprints have year by year? Of course there’s this little thing called the Sun and its variability. Year by year numbers, please. If a butterfly flaps its wings in China, will forcings cause a tornado in Kansas? Of course, the formula all these numbers are plugged into will have to accurately reflect each ones impact on all of the other values and numbers mentioned so far plus lots, lots more. That amounts to lots and lots and lots of circular references. (And of course the single most important question, will Gilligan get off the island before the next Super Moon? Sorry. 😎
There have been many short range and long range climate predictions made over the years. Some of them are 10, 20 and 30 years down range now from when the trigger was pulled. How many have been on target? How many are way off target?
Bet your own money on them if want, not mine or my kids or their kids or their kids etc.”
Some atmospheric nitrogen molecules play into this.
We don’t have to go to the Amazon to see the huge benefit higher levels of CO2 is having on green growth.
Fortunately those of us responsible for cutting hedges and grass have has a slightly less busy summer thanks to some great weather and sunshine here in the UK .Normally I am busy mowing and cutting stuff back, but this year it has been drinks on the terrace thanks to lovely sunny weather that has reduced the summer growth we normally see.
It has been a year of fantastic apple production and plums. Long may this trend continue.
More CO2 please.
NB I know the British farmers have had it tough with hopeless grain harvests and grass shortage due to lack of rainfall.
There is no real evidence that CO2 has any effect on our global climate system. There is plenty of scientific rationale to conclude that the climate sensivity of CO2 is effectively zerol The AGW hypothesis has been falsified by science. M Mankind does not even know what the optimum global climate actually is let alone how to achieve it. Spending mowny trying to fight climate change is a big waste of funds.
Carbon dioxide is way more than mere fertilizer. CO2 + H20 and sunlight yields the basic building block for life on Earth. CO2 is just as important as H20.
Astonishing….who would have ever thought that trees GROW ?
Did someone pay these “researchers”? Did they need some fluff for their CV’s?
/s