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.

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.

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.

They say it would take a forest the size of New Mexico "to account for one year of American emissions" - given that trees both process CO2 during respiration and act as sinks when they grow, I can't tell if they'd be able to offset those emissions the next year as well or if we'd need a new forest.

Trees produce CO2 during respiration and intake it during photosynthesis. The carbon captured during photosynthesis will be offset to some degree by the tree's own need to consume glucose.

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.

Why are they focusing on making bio-oil to throw away instead of biochar that has many known non-fuel uses? https://en.wikipedia.org/wiki/Biochar#Applications

Nice!

There's been a proposal to bury them not-so-deep, but saturated with salt to prevent decomposition. It's not necessary to sequester the carbon forever, just on a time scale for natural absorption of the CO2 into oceans and then into carbonates (which is something like 100,000 years, IIRC).

So that someone in the future can discover these reserves and use it as fuel?!?!!?!

No, by then it's at least conceivable that cold fusion will by then be a reality. If an individual cracks this problem maybe they'll offer a paper ending with a comment akin to Watson & Cricks 1953 paper on DNA. "It has not escaped our attention that ..." Or words to that effect.

https://www.youtube.com/watch?v=PGgovWTBoWY (Hossenfelder) https://lenr-canr.org/ (Library)

It's wonderful how pseudoscience is a renewable resource. Ghosts, then ESP, then pyramid power, and now cold fusion.

https://www.livingcarbon.com - they actually genetically engineered trees to grow faster.

Biochar is exactly doing that and is an active area of research in many places. There is several ongoing projects also showing that biochar can improve soil quality and crop yields.

We need to be building a mountain range out of diamonds.

Can you imagine the extraterrestrial archaeologist trying to explain that?

No - stupid slow speed of light stops so many interesting science fiction imaginations.

Reality is very much a bummer.

Some of those interesting scifi scenarios would not be so good for us.

It's true that the speed of light prevents it from actually happening, but you should still be able to imagine it.

The nice thing about making diamonds as opposed to coal or bio-oil is that it's quite hard to burn the diamond, so less chance of someone getting tempted into using these enormous reserves that are just sitting there, depreciating, to fuel the helicopter of their bitcoin-mining luxury cruise ship or create an ultra-fast pizza delivery service using rocket launchers

Depends on where the carbon goes. Into a home? Locked up for a long time. Under a cooking stove? Released.

But does it help worrying about where we're putting logs while we're burning fossil fuels? We need to plant enough trees to offset all the trees we're burning, but also all the gasoline, oil, and natural gas we're burning as well as all the concrete we're producing. The math seems like it'll never balance.

I did the back of the napkin math below: https://news.ycombinator.com/item?id=42697255

Barring mistakes, it balances if we had avoided reducing the planet's vegetation by 20% since 1900. So much for that.

That's obviously not "the" solution, but it seems like reducing fuel burn while increasing forestation would benefit us beyond what is commonly expected.

Interesting math, so it is mathematically possible. Important to note, 1 billion hectares is just over the size of all of the United States.

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.

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%...

gain yes, but not one showing the losses per country

Happy to be your personal google, gives me an excuse to look at it again.

This dashboard is good for that https://www.globalforestwatch.org/dashboards/global/?categor...

This visualization is also good: https://ourworldindata.org/deforestation

Thanks for these pointers, I really didn't mean for you to go out looking, was just complaining a bit about the presentation of that first site ;-)

Interestingly, the first forest watch loss (pink blob) I zoomed in on there turned out to be a project initiated by a local environmental organization to restore an island to its original farmland (as it had been up until a century ago and for centuries before) with wild sheep keeping the trees down, small bushes and wide range of local flowers instead of deep tree cover. And the nearest "forest gain" (blue blob) was a park tree. As Yolland the disenchanted mapmaker said, "Something is being eroded."

No worries at all :)

> 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.

What happens when the forests in those places burn down?

Depends on how they burn and what forest we are talking about. A small intensity fire will leave many of the healthy trees alive while burning dead ones, and will turn some of the carbon into charcoal which is sequestered. A larger intensity fire will also kill healthy trees, and turns the carbon into CO2.

Many of the forests in North America need to burn every year in that low intensity fire. Their seeds won't even sprout until after a fire (when all the dead undergrowth has been burned away thus leaving the new sprout with sunlight). However this doesn't apply to all forests in North America, and I know even less about other countries.

Moral of the story: consult a forester who knows the local forest before talking about anything. In many places we have been badly mismanaging forests and there is no nice way out. We probably do need to burn down and start over with large parts of North America because of all the harm decades of "Smokey the bear" have done to our forests.

That depends on how many of them burn. A few? Doesn't matter much. All? Goodbye, and thanks for all the carbon.

What percentage of burning down over what time scale?

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.

I wonder if declassified cold war spy plane photos might be usable to extend the records farther back in history? The resolution and coverage should be pretty good.

They didn’t take high resolution photos everywhere back then. In the early satellites it used physical film they recovered. And later digital storage and bandwidth was expensive and they dumped any data they didn’t need.

I'm not thinking of early satellites, but rather spy planes like the U-2 and SR-71 (and their equivalents in other countries). They would take use big long reels of physical film, covering quite broad areas on continuous capture from high altitude. It's possible that much was discarded but my guess is that most of it was archived somewhere for the intelligence community. (I'm sure that some areas of the world got more attention than others, of course).

Be interesting to go back even further, pre agriculture. The world would be awash with trees.

Not really. In some places yes, but trees need specific conditions to exist: there would be lots of grass land and deserts too.

And it’s not just trees. Ever heard of “justdiggit”?

They found that digging holes in the desert functionally accumulates enough water to promote diverse plant life. It’s apparent an ancient practice. They organize groups to do it. Ecological stewardship is, I hope, a key shift in mindset from the current totalizing view of global warming.

https://justdiggit.org/

I didn't know about this but after several documentaries on the medium to long term impact of these projects many areas being more detrimental than beneficial I tend to be a bit skeptical. I get particularly skeptical when the whole website is geared towards taking in corporate donations rather than teaching how to do it and direct action and a sort of wiki of how to do it yourself as well as evangelizing that.

I didn't spend too long on the website but this page https://justdiggit.org/dig-in/farmer/start-regreening/ seems to be the closest to that, yet it's still no instructions and just marketing. I don't want to sound too negative or make a judgment call with too little information but wanted to share my worries as it has become all too common for grifters to take advantage of the situation in a sort of partnership with huge corporation leadership teams. They get free money and the leadership team gets to greenwash whatever they do in their core business.

I never researched this specific one in detail other than a few minutes now, but the company I worked for previously used to do this style of donations and we found a lot of projects like this.

So take a minute to look at their impact reports and then we can discuss the evidence.

https://justdiggit.org/wp-content/uploads/2024/06/Justdiggit...

Sorry I shared the main link— they are an NGO that raises money, that’s how it works.

I just find it hard to understand that if you really found out digging holes has this much impact, and you truly care, that you wouldn't share schematics and detailed guides on how to do it in your own land, does that make sense? They would of course still try to do larger projects, but it just feels strange enough to cause doubt for me. Sorry if it's a misjudgement.

Water bunds, and other approaches to re-greening are part of a United Nations-funded project. You can see other examples (including instructions) at these sites:

https://www.decadeonrestoration.org/

Instructions:

https://amshaafrica.org/index.php/building-water-bunds-a-ste...

Thanks for sharing, maybe I'm demanding things they aren't set out to do and being too cynical.

Yes, that's my take of your position.

There is plenty of literature about the effectiveness of swales and bunds. Justdiggit didn't invent them. Their expertise is in mobilising communities to actually implement them, and raising funds to support them.

Agreed. It's the corporate equivalent of sinning left and right 6 days a week, then going into the confession booth on Sunday and getting asked to recite a couple of Hail Mary's.

We should get prisoners to just randomly dig holes in the sand, a shovels length in diameter

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)

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.)

Search for „rewilding“. It’s a popular approach in the UK but you’ll find projects in other countries, too.

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.

> 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.

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.

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.

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.

>and when the roots break down all that carbon is released to the atmosphere.

How do you figure, exactly?

Bacteria and other organisms “eat” the wood, and then “breath” out CO2 (and sometimes methane).

https://en.wikipedia.org/wiki/Soil_respiration?wprov=sfti1#

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.

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.

I guess a tree farm (if the trees are used for construction and not burning) would be significantly net negative for atmospheric carbon, especially if the operation was entirely powered by solar and electric?

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.

Regardless, the net carbon sink of a healthy forest is higher than the net carbon sink of a few houses that were built in its place.

Simply think of the number of tons of wood in an acre of forest, compared with the number of tons of wood in a housing development.

It doesn't matter that some trees die and release their carbon, other trees grow. Instead of thinking of individual trees, simply think of the entire biomass of the forest.

A tiny amount is turned to coal (often via forest fires) which then isn't returned to the cycle. We are talking about -0.1C over thousands of years though, if we otherwise went carbon neutral - which seems unlikely for the long tail of small users but if we get the major uses of fossil fuels to something carbon neutral that would get us very close to stopping global warming at least.

I’m talking specifically about when trees are used for lumber.

I think the subsistence farmers cutting down the Amazon are doing more burning than construction.

Much less than half of the tree mass is used that way. (But of course also the part in buildings is there only temporarily, for the lifespan of the building)

Underestimated by one quarter! A factor of 4/3 or 3/4.

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.

>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.

Ok, we've made the estimates rise in the title above. Thanks!

> 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.

At least in the UK woodland cover is increasing. It was 3% back in 1900~ and today it stands at about [13%][0]. The aim in the UK is to be at 15% woodland and tree coverage by 2050 – quite achievable.

I currently teach woodland management and arboriculture (I also run a weird hybrid business doing software and arboriculture) in the UK and the idea that we cut down more than we plant is a common misconception that I spend a lot of time (and I mean a lot of time) correcting with the public and general layperson. Felling trees for forestry purposes requires a felling license[1], which always comes with a re-stocking clause.

As for urban green infrastructure (basically private and municipal trees and hedges), that comes with it's own issues, and there's a lot of wins to be had there but there are also lots of challenges. I know the Arboricultural Association in the UK are doing some great work here to advocate for finding ways to retain private and municipal trees whilst managing risk to the public (the main reason trees are normally removed second only to "aesthetic").

Biodiversity Net Gain (BNG) is also a thing in the UK which broadly translates to ensuring that any private building works or developments must now have a demonstrable positive effect on local biodiversity and where that's not possible, then developers can "offset" by commissioning biodiversity projects elsewhere. For example, I've just taken delivery of 1200 trees (oak, hazel) today, which will be planted into semi-ancient woodland that I manage.

So basically the idea that we're cutting down forest ahead of what can restock isn't accurate, in fact in the UK at least, it is quite the opposite.

A good news story for you.

[0]: https://www.forestresearch.gov.uk/tools-and-resources/statis....

[1]: unless it is a) less than five cubic metres in a twelve week period (basically "thinning" woodland so that other trees have room to grow / habitat improvement for priority habitats). b) a private tree without a preservation order/ fruit tree, c) diseased or dying or d) a suitably high risk to public safety.

I heard that the major problem with replanting efforts is monoculture. What are your thoughts on that?

It depends. For forestry stock there's no real way to avoid monoculture if you need a lot and you need it soon (40-60 years). There's much more to this answer though because Phytopthora is hammering larch, Ips is hammering spruce and red band needle blight is hammering pines. That's another topic on itself. Broadly though, there's nothing wrong with a monoculture per-se ([Pando][1], Boreal woodland) it just depends on how it is managed and how well the ecology does in response to it.

That being said, personally, I favour the continuous cover approach of mixing up natives broadleaves with non-native conifers as long as the site isn't ancient or semi-ancient natural woodland (ASNW) or plantation on ancient woodland site (PAWS). For those sites, they're too important for use as a commercial forestry site and arguably the ecology needs to be restored, maintained and managed. Those sites are precious and should be managed properly in-line with their identified [NVC identifier][2]. The one exception to this is coppicing. Having a coppice on ancient sites where coppicing was practised is one of the few woodland management techniques that adds to ecology over all four woodland layers over all time frames.

I never thought I'd answer that question on HN. I appreciate you asking. What's your take on forestry monocultures?

[1]: https://en.wikipedia.org/wiki/Pando_(tree) [2]: https://jncc.gov.uk/our-work/nvc/

Super interesting!

My preconception (not a botanist) was that monocultures were automatically worse for local ecologies. I wonder if lumbering practices in America are similar. Obviously, it's a mix of good and bad, but it would be cool to find some research that suggests how we're doing.

I also just like an eclectic, vibrant forest, and personally, monocultures ruin that vibe for me. I'm pretty spoiled though, having lived much of my life in heavily-wooded areas.

I think they mean the global CO2 uptake from plants is 30% higher overall not that a single plant is able to uptake 30% more than the estimated before.

Even though more CO2 pressure in the atmosphere increases also the potential uptake in a plant.

> Too bad that we are currently doing the exact opposite (cutting down more forest than is regrown)...

"Plants" is not a synonym for "trees". There are grasslands that are significant carbon sinks - even farmland managed in the right way can be a carbon sink . The oceans (which have a notable lack of trees) are a major carbon sink (although this paper is not talking about this, if I understand the abstract correctly).