Estimates of plant CO2 uptake rise by nearly one third
141 comments
·January 14, 2025rob74
vasco
Not everywhere, between 2000 and 2020, 36 countries managed to get more tree cover than they lost, so we "just" need to expand this practice.
https://research.wri.org/gfr/forest-extent-indicators/forest...
> Even though the world gained 130.9 Mha of tree cover between 2000 and 2020, it still lost much more, with an overall net loss of 100.6 Mha. While the global numbers report a negative trajectory, there are distinct regional patterns or “hotspots” of net gain. At least 36 countries gained more tree cover than they lost over the 20-year time period. As a continent, Europe gained 6 million hectares of tree cover by 2020. Asia also had a large proportion of countries with net gain, particularly in Central and South Asia. The drivers of much of this gain (for example, what proportion is due to intentional restoration interventions versus land abandonment) are still difficult to determine using the available data, but are a key area for future research. Additionally, even though tree cover gain is occurring in many places, it doesn’t “cancel out” the impacts of loss. Primary forests in particular serve as critical carbon stores and support an intricate network of wildlife, none of which can easily be replaced once lost.
internet_points
That first map makes it seem like we had gains pretty much all over the world, but it's not showing net gain, most of the countries of the world had a net tree cover loss. I wish it had a map showing net losses per country too – and it'd be interesting to see it going back in time, many countries had periods of very extensive logging during the 1800's and 1900's.
vasco
If you scroll there is indeed a map with net gain in the page I shared. Direct link to the net gain map file here: https://research.wri.org/sites/default/files/gfr/2022-10/36%...
geodilg
Forest loss data is available for the study period (2000 - 2020). I've worked with this specific data source quite a bit. While it's known for being the gold standard in global forest loss estimation there are many countries that criticize it for over estimating loss. Going back further than 1985 is difficult/impossible as the estimate is derived from satellite data.
onlyrealcuzzo
> most of the countries of the world had a net tree cover loss.
This also doesn't really matter.
Russia, Canada, Brazil, the US, and China are about ~60% of the world's trees.
Their forest areas could grow by only 2-3% and dozens of small countries could lose substantial percentages of their forests, and we'd still end up with a ton more trees and forest area.
_joel
Be interesting to go back even further, pre agriculture. The world would be awash with trees.
SketchySeaBeast
I don't know that getting more trees than you lost is a useful or effective measure against climate change. It's a good thing, certainly, but I imagine the amount of carbon we're pumping into the atmosphere requires more than a steady state of trees. I wonder how much of the world we'd need to cover with trees in order to offset our carbon production, certainly more than we've had during modern civilization.
internet_points
https://climate.mit.edu/ask-mit/how-many-new-trees-would-we-... says a new forest the size of New Mexico might offset the US's emissions. Or not. It depends. But first thing to do would be not to cut down the existing ones.
baq
Basically we need to grow trees as fast as possible, cut them down and bury them deep, exactly the opposite of what we’re doing when mining fossil fuels. No wonder there’s exactly zero people doing that.
thfuran
We need to be building a mountain range out of diamonds.
tomrod
Depends on where the carbon goes. Into a home? Locked up for a long time. Under a cooking stove? Released.
deelowe
> Too bad that we are currently doing the exact opposite (cutting down more forest than is regrown).
This is not true. Sustainable forestry practices have been increasing forest coverage for some time now.
yobbo
> Too bad that we are currently doing the exact opposite (cutting down more forest than is regrown)...
Carbon is captured when trees grow. Lumber binds carbon into buildings and constructions.
Ma8ee
Old forests sequester more carbon than new ones. When you cut down a tree, you leave half of it under ground, and when the roots break down all that carbon is released to the atmosphere.
It is far from straightforward whether it is better to leave the forests standing or cut down and replant. The forestry industry is of course claiming that a cultivated forest is better for the climate. The environmentalists are claiming that old forests that are left alone are better for the climate and in addition better for ecological diversity.
I tend to believe the side whose income doesn’t depend on their claim.
jncfhnb
Sounds dubious. Most trees are not nearly 50% roots by biomass. The roots that remain will get broken down, but not into gases exclusively. A new tree that’s growing is actively capturing new carbon. Cutting down a tree won’t help much, but if a new tree grows where the old one was, it’s hard to find reasoning to suggest a net loss.
rwyinuse
What happens to the parts that are cut down and used is what matters. If you build long-lasting houses from them, then it's probably good for the climate, as long as new tree is planted in its place. If you use the wood to make toilet paper, then it's not so good for climate since that carbon will return to the atmosphere faster.
zahlman
>and when the roots break down all that carbon is released to the atmosphere.
How do you figure, exactly?
snowwrestler
It’s a net negative over time if the square footage that was housing a tree is replaced with grassland or a neighborhood. You trade a one-time, one-tree-sized fixing event against all fixing by all future generations of trees on that spot.
The climate math of lumber works if you’re talking about “productive forests” where trees are allowed to grow to replace trees cut down. It doesn’t work for situations when a forest is cleared and not replaced, which is mostly what is happening where rainforest is being cleared.
lotharcable2
In the USA, at least, most the lumber for home construction is farmed. We don't rely on "old growth" for much anymore.
Meaning the forests are kept forests and new trees are planted to replace the ones that are cut down. The land the trees are farmed from is kept forested because it provides a income source for the owners. Also the trees tend to grow much faster then they do in natural forests because things like spacing out trees is optimized.
This is a big complaint for wood working folks, ironically. Because natural grown trees grow slower the wood grain is much tighter and ends up being generally higher quality. Where as modern farmed wood has huge rings.
Although it isn't too bad because you don't use soft woods much for things like furniture making. Where as construction lumber is almost all soft wood.
So at least in the USA the ratio of grown-to-cut wood is about 1.92. So we plant trees nearly 2 to 1 versus what we cut down.
mech987876
Most (all?) of the carbon sequestered by a tree that dies and rots on the forest floor goes back into the atmosphere. So the "fixing by all future generations" is just the same carbon sink as the current 1 alive standing tree for that spot of real estate.
thfuran
I think the subsistence farmers cutting down the Amazon are doing more burning than construction.
internet_points
Are there any good charities that buy up green land for the sake of not doing anything to it? From what I've read of carbon capture economics, it seems a frillion times more effective to simply not chop down more forest compared to investing in carbon capture (though I'm not saying we shouldn't do both)
snowwrestler
Yes, the Nature Conservancy is a large nonprofit that buys lands to hold in its natural state, albeit not at the scale needed to offset industrial activities. They tend to focus more on qualities like undisturbed ecosystems, or biodiversity, than climate change.
And in the U.S. at least, many states have a concept of a conservation easement where you get a tax advantage by promising not to disturb or develop land you own. This is used by some wealthy individuals to lock up a bunch of land undisturbed. But again, so far it is not remotely close to offsetting the overall human behaviors that are forcing warming. (As evidenced by the directly measured rising CO2 levels and temperature anomalies.)
dpcx
Not exactly what you're asking for, but [Ecologi](https://ecologi.com/) is doing lots of work on the tree-planting front, but also doing other work that helps with climate change, like solar panel setups in Morocco, wind farms in the US, methane emissions in Brazil, and more.
tfourb
Search for „rewilding“. It’s a popular approach in the UK but you’ll find projects in other countries, too.
HPsquared
Underestimated by one quarter! A factor of 4/3 or 3/4.
dang
Ok, we've made the estimates rise in the title above. Thanks!
moralestapia
>Too bad that we are currently doing the exact opposite (cutting down more forest than is regrown)...
Hmm, anyone has data on this? I've seen many people claiming the opposite of that opposite.
rasengan
There are plants in the ocean that man will have trouble to cut down.
Earth isn’t the same kind of living organism as man, but it’s an organism just like AI isn’t the same intelligence as that of man’s, but it is intelligence.
klausa
As I understand the article; it’s not that we found out that they’ve _started_ absorbing more CO2; it’s that the previous estimations were flawed and we have new, improved ones.
coffeebeqn
Isn’t this common knowledge among plant growers anyway? Plants can easily enjoy a co2 ppm of 1000+ in a greenhouse for faster growth. Photosynthesis involves an exchange of co2 to oxygen
https://extension.okstate.edu/fact-sheets/greenhouse-carbon-....
pmayrgundter
Not clear from the linked article. Did you see something else?
NPP is probably increasing as it's been observed for years now that the earth is net greening in response to rising CO2
adamors
Interesting that a couple of months ago there was an article which stated the exact opposite:
> In 2023, the hottest year ever recorded, preliminary findings https://arxiv.org/pdf/2407.12447 by an international team of researchers show the amount of carbon absorbed by land has temporarily collapsed. The final result was that forest, plants and soil – as a net category – absorbed almost no carbon.
> “We’re seeing cracks in the resilience of the Earth’s systems. We’re seeing massive cracks on land – terrestrial ecosystems are losing their carbon store and carbon uptake capacity, but the oceans are also showing signs of instability,” Johan Rockström, director of the Potsdam Institute for Climate Impact Research, told an event at New York Climate Week in September.
> “Nature has so far balanced our abuse. This is coming to an end,” he said.
https://www.theguardian.com/environment/2024/oct/14/nature-c...
gvx
Not exactly. The headline is a bit misleading imho: the article doesn't say that CO2 uptake by plants is up by 31%, rather that new estimates of the CO2 uptake by plants is 31% higher than previous estimates. That doesn't preclude a temporary collapse of carbon absorption (related mostly to forest fires as far as I can tell).
carrychains
That's not the opposite. It's different context.
know-how
[dead]
null
myrmidon
This is interesting to know, but easy to overstate IMO.
Back of the envelope number is 10 kg of CO2 absorbed per maturing tree and year (for ~20 years).
This means you would need to plant almost 1000 trees for each person (assuming roughly US/EU emission level) to compensate for current emissions only, every 20 years. That just seems infeasible to me, and a factor of 30% is not gonna change this significantly.
Renewables + electrification seems much more realistic, when countries like France are already under 5 tons CO2/year/person by relying on carbon-free electricity (US is at 15!).
But it's still nice to know because at least planting/conserving trees apparently helps even more than expected...
Someone
> This means you would need to plant almost 1000 trees for each person (assuming roughly US/EU emission level) to compensate for current emissions only, every 20 years. That just seems infeasible to me
That’s 50 trees each year for each person, or, in the USA, about 17 billion trees, for a total new forest of 340 billion trees.
https://www.washingtonpost.com/news/energy-environment/wp/20... says the USA has about 280 billion trees, so we’d ‘only’ have to grow that by 120%. That would grow forest in the USA from about 33% to about 75% of land area.
Infeasible, but not completely impossible, I would think, from a ‘could we do it?’ viewpoint. ‘Is there a decent chance we’ll do that?’ probably has the answer “no”, though. For the USA, I guess cutting combining forestation with decreasing energy usage would be the easier option.
myrmidon
Thats an even bigger area than I imagined... Another big problem is that we'd have to grow those forests again after 20 years, because mature trees stop being a CO2 sink.
The numbers/ratios should be even worse for Europe where the population density is higher. But I can totally see the approach working after scaling CO2 emissions down.
I think going over single digit percentages of land area in forestation levels is already politically almost impossible-- agriculture alone is gonna meet any such attempt with ridicule at best and copious amounts of buckshot at worst...
p0w3n3d
there are also organisms in water:
> On a global scale, oceans and other water bodies absorb approximately 25-30% of the CO₂ emitted by human activities each year. This absorption occurs primarily through two mechanisms:
> - Physical Dissolution: CO₂ dissolves in water and reacts to form carbonic acid, bicarbonate, and carbonate ions.
> - Biological Processes: Aquatic organisms, especially photosynthetic ones, play a significant role in capturing and sequestering CO₂.
Earw0rm
It's a useful datapoint in understanding the Earth's carbon cycle, but that's all - and it in no way changes the fact that the sum total of current human activity is dragging that cycle out of equilibrium by about 2.5-3ppm per year, or 8-10%ish per decade.
narrator
Ok guys, this climate change stuff is temporarily off the menu until we win the great power AI war with China. Same goes for nuclear power. Send the memo out that we love nuclear power now after 40 years of hating it.[1]
[1] https://www.ft.com/content/96aa8d1a-bbf1-4b35-8680-d1fef36ef...
Prunkton
>used new models and measurements to assess GPP from the land at 157 petagrams of carbon per year, up from an estimate of 120 petagrams established 40 years ago and currently used in most estimates of Earth’s carbon cycle
>One petagram equals 1 billion metric tons, which is roughly the amount of CO2 emitted each year from 238 million gas-powered passenger vehicles.
this sounds pretty significant. Any particular reason why it hasn't been updated for the last 40y?
baq
Impressive, yes. Important? Absolutely. Significant? Not really.
Terr_
Unfortunately this doesn't mean much for the practical problem, because most of that uptake is is dumped into the atmosphere again when the plant dies and rots.
It's like we've got a bathtub where the water level is rising, because we won't turn off the tap and the drain is only so big. We can lower the apparent water-level by throwing in a bunch of plant-sponges, but we can't just keep adding more indefinitely.
eggy
If it has been underestimated then that means climate models have been using the bad, underestimated data, so they need to be updated and run to see where we are at, corrrect?
bradjohnson
No. Climate scientists did not base all of their current models on a 1980 study about how much CO2 trees can technically absorb.
jeffbee
No because we aren't reliant on a model of atmospheric CO2 concentration. We directly measure it.
wiz21c
You measure the past, but you don't measure the future, right ?
jeffbee
Right, this new estimate can be useful for decision support: if we plant X acres, how much CO2 would it absorb? It's not very important outside of that, and it cant have caused significant past errors because to date humans have not undertaken large-scale planting for CO2 absorption reasons.
OJFord
I assume they mean for things like offsetting programmes, predicting the continuing trend and effect of governments deciding to plant more/less, etc.
jiehong
We know that soils seem to absorb less carbon as plant absorb more [0].
It's fascinating to see all those studies improving our limited understanding of the biosphere.
gitaarik
> Plants the world over are absorbing about 31% more carbon dioxide than previously thought, according to a new assessment developed by scientists.
So that means our supposed CO2 problem is 31% smaller than we previously thought?
teamonkey
No, the atmospheric CO2 measurements are unaffected by this. We definitely have a CO2 problem despite plants being more effective at extracting it than previously thought.
Another way of looking at it is that planting trees may be more effective at removing CO2 than previously thought, and deforestation somewhat more harmful.
gitaarik
Well, wouldn't it be correct to say that now, with the new numbers, CO2 uptake of plants will be 31% more than previously thought? So every coming year, there will be 31% more CO2 converted into oxygen than previously thought?
mzhaase
That just means that CO2 emissions are actually higher than previously thought. We directly measure atmospheric CO2.
thehappypm
Sadly not, because most carbon is absorbed by the ocean, not plants. And second because all of the nasty warming trends are still out there
gitaarik
Or this statistic means that actually much more oxygen is converted by plants compared to being processed by the ocean?
So it means planting extra plants to fight CO2 is much more effective than previously thought?
OtherShrezzing
Previously we believed that ocean, wetlands, soil, and geological activity absorb about 75% of the CO2. Plants account for around 25% of the carbon absorption.
The research doesn't indicate that more carbon in total is absorbed than we thought - we've got a pretty solid understanding of the total carbon absorption capacity, because we measure it directly, rather than model it. It indicates that a larger proportion of the carbon absorption comes from plants than we thought (around 33%, instead of 25%), with the other sources taking on proportionally less of the absorption.
This research will allow us to more accurately model how land use impacts CO2 though, and will likely put a higher premium on protecting plant life in any carbon assessments.
gitaarik
Aha, yeah that makes sense. But I can't really see that in the article.
Flozzin
I would say no. We still have data on our year to year/decade to decade C02 in the atmosphere. So we can track how quickly it's rising. Those data points would already include any error we have in how much C02 is absorbed or created.
bradjohnson
> supposed CO2 problem
No. This study has changed precisely nothing about how we measure CO2 in the atmosphere. Or climate change in general.
null
IvanK_net
We could plant, cut down and burn trees for the energy, in a circle, and keep carbon levels in our atmosphere the same, instead of digging up new carbon from the ground and burning it. We will have to bury carbon back under the ground at some point.
pjc50
This consumes far more land area than we have available.
The first blast furnaces were indeed fuelled this way, from locally sourced charcoal, but coal/coke took over due to requiring far less effort (energy!) to extract.
Going by https://www.drax.com/uk/sustainability/sustainable-bioenergy... , the UK's single large scale biomass power plant is fuelled by over sixteen million hectares (160,000km^2) or approximately one Wisconsin. If we wanted to power the whole UK electricity from biomass, we'd need ten Wisconsins. (Wisconsin, presumably, would have to find some other source of power in this scenario)
(of course, Drax wasn't built to burn imported biomass, it was built to burn locally extracted coal ...)
OtherShrezzing
Drax uses about 12,000km^2, not 160,000km^2.
A slightly more useful land area is the United Kingdom itself, which is 243,000km^2. With this technique, it takes an area 1/19th the size of the UK to produce 4% of its energy.
This isn't a feasible approach to energy production, but it's an order of magnitude less bad than your figures have put forward.
voisin
> We will have to bury carbon back under the ground at some point.
Location doesn’t matter. Duration of storage matters. If we could find a way to lock it up in a building material that would be effective and useful.
gs17
It's not exactly turning CO2 into bricks, but there's a few applications of biochar as an additive to improve concrete, asphalt, particleboard, etc.
bmacho
Yes. That's what my view is. If we cut down the trees, and burn them, we'll have the same level of C atoms in the atmosphere. If we keep using gas and oil coming under the ground, the number of C atoms will keep increasing.
Although I am not exactly sure about the ratio of the C atoms stored in the atmosphere, and C stored in trees, houses, but it seems to me the Logical move that we should stop getting gas and petrol from under the ground and start using trees and other plants instead.
nubinetwork
Trees take too long to grow relative to how much is used in construction, let alone if it were used as a fuel vs coal.
"rises by nearly one third" sounds a bit strange to me, more correct would be "Plant CO2 uptake is currently underestimated by one third according to new research"?
> The research, detailed in the journal Nature, is expected to improve Earth system simulations that scientists use to predict the future climate, and spotlights the importance of natural carbon sequestration for greenhouse gas mitigation.
Too bad that we are currently doing the exact opposite (cutting down more forest than is regrown)...