A revelation about trees is messing with climate calculations | Hacker News Reader

A revelation about trees is messing with climate calculations

wired.com

311 pointsbilsbie182 comments

I find this stuff absolutely incredible. I’ve been learning recently about this phenomenon being known, but not understood.

The most obvious indication was that logging leads to less rain, so it seems as though trees actually cause rain.

One theory was that turbulence in the air above forests could trigger precipitation, and while that might still be a factor, this explanation is very clean and easy to understand.

This is awesome in any case. I’ve been wanting to use the “trees cause rain” point in discussions about forestry and hydrology, but had to be careful because we only had correlations as far as I knew. This doesn’t fully solve that, but certainly helps explain and create a causative link.

Also just incredible how evolution works. Of course trees cause rain, haha. I wonder if other plants such as grasses in vast plains have their own tricks to seed rain, or if their strategy is surviving drought extremely well. It’s all cool either way.

I’ve been reading agroforestry and permaculture books for a while — I’d love to get into farming —, and this has been known for ages.

Even if not fully understood, it’s well known in agro that trees raise the humidity level of an area and create micro-climates that increase the amount of rain (e.g. of doing nut trees in a valley).

I think… modern agriculture just forgot/ignores ancient knowledge.

Are you telling me the Rain Follows The Plow folks were actually on to something?

Solid joke :) .

Unfortunately, you typically don't plant trees with a plow.

Actually you do, at least when planting on a large scale. A planting plough is pulled behind a tractor, the device opens a furrow into which seedlings are dropped at a regular interval by someone riding the plough or mechanically. The furrow is closed with the top of the seedling sticking out.

Here's how you can convert an old plough to a tree planting plough:

https://core.ac.uk/download/pdf/228205053.pdf

I bet there's folk tales that parallel it with angry forest spirits, too. Explaining the unknown with anthropomorphization.

local humidity levels is just transpiration, which yeah in a valley trapping the humidity can create rain but that's not the same as this cloud seeding mechanism.

Without a doubt, and it’s well known in urban planning and landscaping too. But in a discussion about why industry might be harmful, not having facts to back yourself up makes your case effectively irrelevant. Even pointing to countless reforestation projects with heaps of positive precipitation and hydrological data is no help; as long as the mechanism isn’t clear, people who want to maintain business as usual will not listen.

So, information like this is a huge help and a step towards having a more crystallized picture of why forests are crucial to hydrology.

Terpenes from trees also produce OH which converts methane to CO2. No idea whether this has a big effect, but I find it fascinating.

The increase in humidity is actually a different effect - evapotranspiration from trees is included in climate models (along with their response to increasing CO2 concentrations) [0].

The effect in this article is more to do with the particulates that form from the chemical emitted from trees. The article doesn't make it clear, but an increase in tree particulates (known as aerosols) would actually cause less rain.

Almost all cloud droplets form on an aerosol particle, so the cloud droplets in a cloud with more aerosols are on average smaller (as the water is spread out over more droplets). These smaller droplets take longer to grow large enough to form rain, an effect which is thought to decrease the amount of precipitation in some regions (although by a small amount).

This effect is also included in climate models, but the sources of aerosol (such as from trees) are more uncertain [1], producing the uncertainty in future climate projections.

[0] - https://gmd.copernicus.org/articles/4/677/2011/gmd-4-677-201...

[1] - https://www.nature.com/articles/nature12674

Modern agriculture didn't forget. It chose differently because quantity is the only measure of success. Trees causing rain has to be substantially less efficient in the short term than irrigation.

The trouble is that reduced forest leads to reduced rain, and irrigation often reduces ground water which is replenished even slower than before. It accelerates water losses a lot faster than anyone expected.

Yes, but that is a different problem than immediate water availability for crop use.

I agree that irrigation needs are urgent. However, we also need incentives towards an eventual transition.

A basic example: contours to mitigate how fast water moves in elevated terrain. Cheap and effective. Then water collected at dug basins in the bottom.

If you have cheap, constant access to water, you irrigate industrially. It’s only when droughts, lack of groundwater, climate effects, etc. kick in that the alternatives become important. But by then, you didn’t put them in place early enough.

So I think farming deserves both short- and long-term thinking. Business as usual won’t work as climate conditions get worse.

> basic example: contours to mitigate how fast water moves in elevated terrain. Cheap and effective. Then water collected at dug basins in the bottom.

Before I respond, I have another question: Are you saying this is something we are not doing and should be?

It's almost as if farmers were inclined to borrow water from their descendants some centuries down the line, isn't it?

If you have a reading list to suggest, i'm all ears.

I’ve lots on my e-reader, but I keep going back to Ben Falk. “The Resilient Farm and Homestead” is super cool, you actually follow their story over multiple years, with the farm’s changes rather well documented! Of course the more scientific books on the topic are better information-wise — some used at uni —, but Falk’s is nice to read.

You should read the extended phenotype by Richard Dawkins if you haven't already

It's fun also because this relationship is explicitly & deeply embedded in some north american indigenous ecologies, maybe others. We've been confidently dismissing it for generations.

Trees are a collection of straws into the ground, sucking up water with negative pressure due to evaporation through the leaves. It's cool that there are cloud-seeding chemicals released as well.

Forests smell and feel much better that clear-cut spaces, I know that much. I'd rather the USDA and Forest Service adopt more-sustainable logging practices, for leased land especially (where the economics equation currently favors clear-cutting), like the Menominee in northern Wisconsin.

i've also wondered how much energy is absorbed by trees, I know on a 100 degree day the coolness of a shady grove well outcompetes the shade of a simple picnic shelter

there's a couple things going on there. Photsynthesis isn't absorbing much its ~1-2% efficiency (so mostly just waste heat) but plants are mostly water which has a high heat capacity so it warms slower than a kiln dried wood structure. Wood/bark is also way less reflective than concrete and (living) plants respond to heat by opening up pores and letting water evaporate out of them (basically sweating) which can lower the dry bulb temperature (especially if there's any breeze).

In infrared, green leaves are more reflective than bare soil or concrete.

Trees also act as thermal sinks. They transfer surface heat down into their roots, where it is cool underground.

More precisely, the temperature underground is very stable. At 8-12 feet there is little to no variation over the course of a year. So in a cold season it will be warmer underground than ambient (this is why foundations are dug “below the frost line”) while the opposite is true during a warm season.

Would evaporative cooling due to transpiration have a significant impact?

They aren't called rainforests for no reason :)

I had always assumed that causality ran the complete other direction! Rain -> happy plants -> big trees draped in ferns and vines and mosses.

trees basically perform cloud-seeding by releasing micro-droplets of oils into the air

"climate: a new story" by charles eisenstein is a great resource on an alternative understanding to climate change then simply "CO2 bad", which he presents as a red herring to ecosystem destruction

conventional wisdom is apparently "fair weather leads to more biomass" when the reality might be "more biomass leads to fair weather" as every ecosystem acts as a chemical and energetic buffer

This is really interesting to consider, and I hadn’t before. It lends a lot more potential weight and credibility to the idea that rewilding plains (for example), thus increasing the biomass there, would have significant climate benefits. This falls deep into the “We can’t know that” category, but I’m a fairly large proponent of leaving more land alone and letting nature do what it does. At the moment, economic activity like grazing cows seems like it could be a net negative since it’s clearly harming the environment while also preventing natural landscapes from establishing, which could have significant ecological benefits.

The idea that biomass can bring stability and better conditions is certainly supported by my aquarium experience, though it’s a closed system. If you limit the number of species, water parameters will swing all over the place. Add more species (particularly plants and micro flora/fauna), and the water becomes clearer and cleaner. Add some small crustaceans, snails, or other animals which love algae and it’ll get even cleaner, and their populations will self-maintain quite well. Add some tiny fish and they will live on the algae, micro fauna, offspring of the shrimp, etc. These systems work well, but they need a huge amount of plants and tiny creatures, bacteria, and small animals to groom and maintain things. Without them, it’ll crash and swing all over until just about everything is dead.

If we imagine the world as a giant aquarium where we inhibit the micro flora and micro fauna, bacteria, and other balances, it certainly seems possible that restoring this would improve all kinds of factors like water and air quality.

If you graze animals the right way you can also increase biomass/help the ecosystem.

Not really true.

https://newrepublic.com/article/163735/myth-regenerative-ran...

https://grist.org/climate-energy/cattle-grazing-is-a-climate...

https://www.nature.com/articles/nature25138

https://www.oxfordmartin.ox.ac.uk/publications/grazed-and-co...

https://plantbasednews.org/news/environment/george-monbiot-r...

“So any story that says it’s good to be farming these livestock, it’s good to be eating these livestock, is a story which justifies among the most devastating processes on Earth,” he said. “It is climate science denial.”

Monbiot linked this denial to the interests of major corporations like McDonald’s, General Mills, JBS, and the Murdoch Network, who he says have “backed and weaponized” the idea that grazing cattle is environmentally beneficial. “The story is false,” he said. “When you make a grand claim such as this one, that livestock can mitigate climate change, either you produce the evidence for that claim or if you cannot produce the evidence you withdraw the claim. The evidence has not been produced, the claim does not stand.”

For what it’s worth, there are other studies indicating this as well. There isn’t good data suggesting we can graze animals on a large scale and increase biomass in a meaningful way compared to other options. The trouble is that other options inevitably include “stop eating meat”, and people don’t like to hear this.

That’s a big if. The vast majority of animals raised in North America aren’t grazed sustainably, especially if you exclude Canada. It’s kind of like saying you can drive without emissions when 99% of the world is driving gas cars, only in this case, there’s no trend towards grazing sustainably and no reason to believe it will start happening (whereas vehicles likely will continue trending towards electric motors). I just can’t think of a better analogy at the moment, but hopefully it makes sense. Proper grazing seems unlikely to ever be adopted on a broad scale, so it’s unlikely to matter that it can be done better.

> aquarium experience

Is this the Walstad Method?

Yes! I love it. Have you given it a shot?

No, I visited a friend of a friend many years ago and learned of it from them. I hope to one day but far too many projects compete for my time.

It’s worth getting to one day! Once you get it started, it’s really not too much work or time, either. But I hear you, too many projects, not much time. It’s a real problem.

Re: grasses surviving drought, I believe they do this by having extremely deep roots (likely among many other adaptations).

Matches what Richard Dawkins calls "the extended phenotype"

From wikipedia ( https://en.wikipedia.org/wiki/The_Extended_Phenotype ):

"Dawkins develops this idea by pointing to the effect that a gene may have on an organism's environment through that organism's behaviour."

Kinda matches the destruction caused by humans beings in the countryside in northeastern Brasil as well. Most of the trees for the somewhat arid climate were felled and droughts that were every 20 years started to become more and more common until now it’s an eternal drought where very little actually grows as it barely rains.

Doesn’t this seem obvious on its face? Any given tree harnesses a tremendous amount of moisture. And it’s constantly “breathing.” Why _wouldn’t_ a preponderance of trees affect ambient moisture (and, by extension, clouds)?

Grasses (Poaceae) catch dew easily and move it towards its center. Most plants sometimes release water drops also (see guttation)

Without exploring the question of why, it makes sense from an evolutionary biology point of view that trees (forests, really, as trees with extensive root systems tend to be pretty drought tolerant) would attract rain. They require it to survive and thrive in the long run

>but had to be careful because we only had correlations as far as I knew

Sooner or later we need to throw caution to the wind when it comes to advocating for behaving more conservatively towards the environment and climate. If we have to wait until we have ironclad proof that we shouldn't be wrecking things, we are A. allowing our caution to be permissive of recklessness, and B. creating a situation similar to the asymmetry of spreading bullshit -- it takes far longer to prove something is harmful than it takes to switch over to some other equally (or more) destructive practice.

Sorry, I'll step off my soapbox now. Not even sure if you were discussing these things in the context of conservation.

It is indeed really cool stuff! The natural world continues to throw surprise after surprise at us, and the more we learn the more it looks like it really is Fern Gully operating in the wilds of our wonderful earth.

Anecdotally, grasses do seem to put off some smell at times, including preceding a heavy rain. To me, they don't seem as as heady and "luscious" like the rich floral terpenes from a forest (then again I'm from the PNW, so I haven't spent as much time in the grasslands). I wonder if it is more soil bacteria that the grasses are in symbiosis with that do the heavy lifting in terms of rain seeding. Neat to wonder about.

I mean is it cool, or incredibly depressing, because the world will march on with its chainsaws obliterating ancient forests in the pursuit of profits?

Wow. I consider myself pretty open minded but the idea that trees are releasing chemicals to seed clouds with is more amazing than I could've envisaged.

Same it’s absolutely beautiful.

Makes you realise how amazing the natural world (everything pre-industrial times) is.

I’d absolutely love to go back 300 years and smell the forests and dive over pristine reefs.

Anyway this has given me more motivation than ever to restart my guerrilla gardening efforts, planting trees in abandoned farmland in my locale.

Beavers building dams is the amazing natural world.

Humans building dams is a sin against the natural world.

We live in Mordor and have the ring.

Some of the most unreligious people I know are also the most bought-into the idea of a nature/humans dichotomy.

What if you told them that indigenous people pre-colonization sometimes built dams, dikes and aqueducts, and made use of irrigation?

Indigenous people pre-colonization had in many cases pretty advanced civilizations going on, with decent-sized cities etc.

A lot of those same people seem to treat indigenous people as outside of being touched by the "original sin" that the rest of us are.

The original sin of farming, or hierarchy, or city dwelling. Problem is that the dividing line between our hunter-gatherer ancestors and civilization are murky and spread out over millennia, and across the planet in varying degrees.

If beavers got as good as we did, they’d be wrong too.

If beavers did what we’ve done, we’d exterminate them because it would be an inconvenience for us heh

It's almost like scale is a quality of its own.

Dropping a snowball on you might tick you off.

Dropping an avalanche on you, and you probably won't have much to say.

Very correct.

A world with co2 emissions from fire stick farming is a whole different game to what we’ve done in the last 100 years.

Except your injecting all this into the conversation right ? I never said it’s “wrong” for anyone to build a dam. I’m saying I’d like to see a world without mega dams, is that ok ?

I blasphemed against modernity…

> I’d absolutely love to go back 300 years

It'd be fun if you could time travel and do it for a few days. I really doubt you'd want to live in that time forever.

unrelated to the broader tree discussion, but i find this comment incredibly indicative of the type of forum this is. only with engineers do you have to state your point and enumerate through all edge cases around how your idea can be interpreted even though GP PROBABLY didn't mean go back and live there until the end of his life. But even so, that's a derailment of the entire discussion anyway. You always have a person that needs to point out something inane like that which ends up causing a tangent discussion. On a forum, it's fine, you have threads, you can just ignore it and move on, but a lot of meetings & real conversations end up this way. there has to be a name for this because I want to call it something and then coach people out of it

This is so true.

+1 on coaching people out of it. Very well put

> On a forum, it's fine, you have threads, you can just ignore it and move on

Yet we're on a forum, and you're not taking your own advice?

> On a forum, it's fine, you have threads, you can just ignore it and move on,

I should note that ^ -- but it also proves my point. Digressions have gravity. And now this digression has created a complete fork of the original intended post.

Well that's how conversations go, coach. One thought leads to another, sometime tangentially.

Don't worry, I'm done here now.

HN comments are often a web or at least some thick threads of tangents. On most forums tangents are downvoted and labeled offtopic in capitals.

In HN comments on the other hand those side tracks are mostly encouraged, I think that is a good thing.

A word for this might be "pedantic".

(You were asking for a name, but I am trying to be pedantic here.)

Let’s wait 20 years and re-assess.

For context I live in US city that everyone knows, and the talk of the town is “when will our tap water will become brackish, and for how long?”

Fun times ahead. Not sure the appeal of the industrial time will stand.

Edit : the when is a matter of days / weeks. Not years. ( salt of the gulf goes up the river )

Have you ever seen The Truman show ? Your comment reminds me of that movie.

I said that I want to visit. Not stay forever.

On the other hand, I’m not sure what it is but people seem to always have to point this same thing out. Actually seems like it’s a more common thing to say nowadays. It comes across as insecurity to me.

“You wouldn’t want to go back to simpler times they are just awful, run along now…”

I grew up around my great grandparents and grandparents. I never heard them say anything horrible about the past. I heard a lot of beautiful things though.

> I never heard them say anything horrible about the past.

Survivorship bias.

Well I don’t think so, some people lived through terrible things. Half my family lost their entire life’s worth due to WW2 and had to leave Europe. Another relative was in one of the worst battles in known history in Asia and had life long problems from that. He would never get on a plane again and was terrified of them.

But they were happy.

So I disagree.

You think that survivors are not an indication of survivorship bias. That’s too naive for words, congrats.

If you think the only way to judge the past is by the accounts of dead people then you might need to get your head read? Have a nice life.

300?

You mean closer to 30,000 years right?

Humans have been shaping the world with fire for a long time.

No 300 would be fine. I’m ok with fire stick farming, it makes forests beautiful, visit North Western Austalia during the dry season if you want to see a truly beautiful landscape shaped by indigenous fire stick farming.

I wonder if this is industrializable as cloud seeding tech?

I mean… Why not just industrialize the planting of trees for that? The damn things are practically free…

Yeah. Thanks for sanity.

I react the same to “we should build drone to pollinate our food if bees are sick.”

Poorly re-inventing the wheels is silly.

I mean human pollinators already outperform bees so if we only care for productivity there's room to grow

we need to get better at it, a lot of reforestation projects fail to successfully establish a new population of trees

There are a lot of places that need rain that don’t have the climate to support a forest. Further, if this effect scales with quantity you can seed areas experiencing droughts.

Essentially the same reason we’ve been researching cloud seeding to date.

Are you french and is envisage an English word?

It is, in fact

Envisage is English

If you’ve ever been among dense conifers trees, you’ll have noticed a mostly blue-ish but ranging from grey to purple haze (like the smoky mountains, or Pacific Northwest).

That’s the terpenes (and other VOC, “volatile organic compounds”) that the trees emit. These react with ozone, creating compounds that scatter blue light.

I am not certain, but I believe this fog helps plays a role (in combination with specific needle microstructures and density) in the formation of water condensation on conifer needles, which they can absorb, either via drip or more directly when it collects toward the base of the needles. The exact capability will depend on the species.

This chemical fog also acts as a communal defense against many pests and pathogens, isolated conifers are more vulnerable without it.

this effect is also the source of the name for the blue ridge mountains.

As well as the Blue Mountains, in Australia.

"Volatile terpenoids emitted in large quantities by the abundant eucalyptus trees in the Blue Mountains may cause Mie scattering and thus the blue haze for which the mountains were named." Amazing!

https://en.wikipedia.org/wiki/Blue_Mountains_(New_South_Wale...

Yishan Wong's startup Terra formation(https://www.terraformation.com/) is trying to tackle climate change with this more or less as the underlying thesis.

I love forests, any sort, but reforestation the right way, as Terra seems to support, takes more time than some are saying we have. The wrong way becomes the right way when it is all you have time for. Iron fertilization of oceans is promising for albedo already, if we can efficiently synthesize these terpenes in the right ratio to seed clouds perhaps that would buy some time.

"that would buy some time."

Or mess things further up, in a way no one did foresee.

It's probably fine to have some solutions that operate on different time scales than the other proposed solutions that others are trying.

@galangalalgol can you expand on "if we can efficiently synthesize these terpenes in the right ratio to seed clouds"?

It is too early for me to grok, and coffee hasn't kicked in yet

More time than we have for what?

The effects of global warming to have disastrous effects on humans.

Fortunately humans are adaptable and in many parts of the world already living in conditions significantly hotter than predicted in the medium term (50-100 years).

I’m much more concerned about the cure being worse than the disease when it comes to novel methods of affecting climate. Plant trees, replace coal/oil with nuclear and solar, keep up on forest maintenance, etc.

I'm sure you are aware that there's way more going on than just a slight increase in average temperature (otherwise maybe ask the people on maui, greece or canada if they like their slight increase in temperate), but I agree that we should be careful with any radical cures.

I have some bad news,the US, China, and India are not going to turn on a dime like the more optimistic green energy revolution people hope. We have time to plant plenty of trees before we turn the corner. It's just the way of things.

I cannot help but wonder what would happen if we released these chemicals at the norther coast of the Sahara while also planting scrub brush, grass, and trees there.

I think financing and assisting reforestation projects is a worthwhile thing to work on, but selling carbon credits directly enables harmful behavior that more than offsets any potential benefits. I wish it were possible for this company to be funded by government grants or the UN or something like that.

Even if carbon credits do absolutely nothing else, at least they impose a cost on carbon release.

Carbon credits are so incredibly cheap, and in most cases completely voluntary, that I genuinely don't believe they have impacted anyone's behavior. Companies and individuals that buy credits either were already planning on reducing their emissions (so in the best case the credits are useless), or don't want to reduce emissions and are using the credits for PR purposes to delay any actual reduction and call themselves "net zero".

Even when they're legally mandated, most credits are completely unverifiable (what ratings agency will be able to certify that a tree you sponsored will last 100 years). It is actively harmful to allow someone to say that since they paid $10 to plant a tree that may or may not absorb a ton of carbon over the next century, that offsets the literal ton of carbon that they just emitted yesterday (and made a lot more than $10 off of). Just tax the carbon and put the proceeds towards ecological restoration, that accomplishes the same thing without letting anyone falsely claim they have offset their emissions, and allows the government to set the price to something meaningful.

I've been saying over and over that there is a lot of stuff that we don't understand and don't account for in climate models but it keeps getting downvoted. There are too many complex variables and interdependencies to be able to model climate accurately. Anyone who has built any simple simulation knows how incredibly fragile they are. The tiniest mistake or omission can throw everything off even when there aren't many variables. The more variables, the stronger the effect (not weaker as some people would assume, the errors are magnified by interdependencies, not diluted in the sheer number of other correct variables).

Simulations are extremely vulnerable to the butterfly effect.

I'd guess there's a thin line between

"There is a lot of stuff that we don't understand and don't account for in climate models" vs "There is a lot of stuff that we don't understand and don't account for in climate models... and so climate models should be ignored"

HN voting isn't always good at parsing nuance.

It's an interesting area I'm unfamiliar with. How are uncertainty bounds communicated in complex, compounding simulation models?

For simpler models you can do a sensitivity analysis by rerunning the model while systematically varying the uncertain parameters. Based on reading a handful of IPCC papers, a similar method is used in climate science for the most important parameters, but is severely limited by the resources needed to rerun the models and the sheer number of parameters.

Basically, any uncertainty due to complexity is mostly ignored and any skeptics who point this out are tarred as "deniers." Combine this with the fact that generally climate scientists do not produce any point predictions to verify models, and I think you can safely ignore many climate models. The papers that do produce explicit measurable predictions tend to find an interesting result by stretching the models to fit a narrative, eg: https://www.nature.com/articles/s41477-018-0263-1

How are uncertainty bounds communicated in complex, compounding simulation models?

Poorly to not at all.

Climate models have been diverging over time. As details are added (e.g. to try and handle clouds) the different teams making models get different results, and the gap between those results has been widening. We are told the science is certain but the reality is the science has got less certain. Journalists don't like to cover this because they see themselves as change agents, and discussing the actual levels of uncertainty would discourage change. This article in WIRED is an interesting exception, maybe it means something.

The gap between models is compounded by another problem. The individual models are often very buggy and suffer severe numerical instability. Even when told to assume no CO2 emissions at all, for which they are programmed to assume a steady state, they often end up predicting a massive ice age or that Earth becomes as hot as Venus. These runs are simply discarded and the issues are covered up.

Because these problems would cause ultra-wide CIs, climatologists prefer to just take an average and then present the predictions without accompanying measures of uncertainty. They also do this with the input data, for which there is also wide uncertainty.

They have little choice in the matter. Climatologists know their models aren't much good. Last year some of the most famous climatologists wrote an article in Nature warning scientists that there was a "hot model" problem, i.e. models were over-predicting actual warming, the very problem skeptics had been talking about for decades. It's paywalled but there's a copy here:

https://www.masterresource.org/uncategorized/climate-models-...

We are climate modellers and analysts who develop, distribute and use these projections. We know scientists must treat them with great care. Users beware: a subset of the newest generation of models are ‘too hot’2 and project climate warming in response to carbon dioxide emissions that might be larger than that supported by other evidence3–7. Some suggest that doubling atmospheric CO2 concentrations from pre-industrial levels will result in warming above 5 °C, for example. This was not the case in previous generations of simpler models.

Not much of this reaches the mainstream.

Canada had record wild fires in 2023 and now I’m wondering how this effect will snowball.

I am too. I think Canadians need to treasure their forests and should be seriously concerned by what’s happening. Our current reforestation efforts aren’t enough, and they’re largely driven to support future logging activity, not restore ecology.

And yet, if we look at the numbers, wildfires are actually nowhere near as bad as they were in the 90's: https://cwfis.cfs.nrcan.gc.ca/data/charts/NFDB_stats_chart.p...

I'd like a ban on people going outside and causing wild fires like we had in 2020 though. That was a good year.

Nope - your chart only shows up to 2021. Wildfires are actually much much worse than the 90s.

“This year’s fires have now burned more than double the previous record of 7.1 million hectares torched in 1995” https://www.aljazeera.com/news/2023/8/23/mapping-the-scale-o...

17.577 million hectares have burned so far this year. If 2023 were on that graph it would be a skyscraper towering over every big fire year in the 80s and 90s.

This year is unprecedented. And it isn't even over yet and the fires are still burning.

But what does that say about the long term trend? Is 2023 an anomaly skewing the data, or does the data actually show a trend of increasing wildfires?

If I'm not wrong, Canada had record wildfires in a very curious set of years.

What so you mean by curious?

https://www.bbc.com/news/uk-66612781 Need to wait and see if there's any charges brought forward for Arson

See it by yourself

https://globalnews.ca/news/8045796/canada-wildfires-yearly-t...

The interesting graphic is the area burnt by year. If we take the years with more than 3 million hectares burnt we have some "specially hot years" falling over yearly average. This set includes:

94-95 Crimean referendum to choose between Russia or Ukraine

98 Russian financial default, start of the Yeltsin demise

Ukrainian presidential elections of 1994, 2004, 2010 and 2014 (but curiously not 2019). Would be specially interesting to check if the wildfires happened after or before the elections.

2013-2014 Euromaidan. Russia anexionates Crimea. Start of the Dombas war.

2017 This is an outlier. The year of Voronenkow saying that Crimean annexation was illegal and fleeing the Duma before to be assasinated. The year of Petya also.

We could probably add 2023 to this list at the end of the year

In the country with the second largest expatriate Ukrainian population. Most probably happened by random (and I'm surely cherry-picking) but still a curious chain of events. I assume that the data shown in this graph is correct (I could be wrong about this).

2020 is also interesting. People at home = no wildfires

Geopolitical events related to Ukraine cause wildfires is what you’re getting at??

91 94 98 03 06 10 12 15 18

3 4 5 3 4 2 3 3

Help me out, what am I missing.

https://arstechnica.com/science/2023/05/wildfire-smoke-from-...

This article about Austailian fires making the recent years' la nina stronger was interesting.

it is amazing how people think we understand climate, when it's the most complex phenomenon on Earth. We do not comprehend half of it, but pretend to know, and even predict climate. A 5 day weather prediction is a total different beast than climate prediction, and even that is proven wrong sometimes.

I mean the planet is as warm as it was predicted to be 50 years ago based on the emissions scenario that played out. Considering the earth is hotter than it's been in 100,000 years I would say that's one of the greatest predictions in the history of earth sciences.

you have a link to that prediction ?

https://eos.org/features/a-50-year-old-global-warming-foreca...

given the rate of publishing climate models, each predicting a certain temperature, one will eventually hit the right point. it's as inevitable as carpet bombing, and it doesn't prove anything.

Nailing the correct amount of warming is the norm for climate scientists not the exception. It's the contrarians who continually make bad predictions.

https://youtu.be/tPSIvu0gQ90

This sort of thing gets claimed a lot (by climatologists) but isn't true. 50 years ago is in the 1970s and there were plenty of climatologists predicting a new ice age back then. Here's an example:

https://www.nytimes.com/1976/07/18/archives/the-genesis-stra...

There's plenty of evidence from other fields that says the Earth isn't hotter now than in the past either. Archaeological evidence, even evidence from written histories, points towards it having been warmer in the past than today. Climatologists don't have answers for that, they just ignore all that evidence. And paleoclimatology is very corrupt. One of them even stated at one point in response to allegations she was cherry-picking data, that "if you want to make a cherry pie you have to pick some cherries"! Not even a denial.

You really cannot take anything paleoclimatologists say at face value unfortunately. They are constantly faced with self-contradictory data and just toss anything that doesn't match what they want.

From 1965 - 1979 there were only 7 scientific papers predicting a cooling climate. Compared to 42 predicting human caused global warming (Peterson 2008). Since then the global average temperature has climbed to 1.8F above preindustrial levels. It's warmer now than it has been in over 100,000 years and those scientists who predicted warming 50 years ago accurately forecasted Earth would be this warm by now with the co2 levels we have.

The hypocrisy to claim Paleo-climate reconstruction is cherry picked, but to also claim there's evidence that it was warmer in the past. Which seems to always rely on cherry picked local data which isn't indicative of global average temperatures. I'm sorry, but I'll continue to rely on the peer reviewed climate reconstructions over the blog posts of climate deniers. Multiple different teams of scientists have come to the same conclusion independently that current temps are above anything seen in the holocene and rates of warming are unprecedented.

If you want to gamble the future of humanity on the longshot bet that an entire field of science is wrong, but that the fossil fuel industry funded bloggers who oppose them are right then you're bad at risk analysis.

Does the term "seeding" have two meanings? I understood it to mean dropping particles into clouds to trigger rain. The article uses it to mean using particles to induce cloud formation.

Good question! The term is more generic, introducing something to an existing system to begin a chain reaction.

Here in N. California I've seen it: the coastal forests breath out cloudstuff. When the conditions are right they breath out something that immediately condenses a mist which rises and becomes clouds that drift inland. The trees on each ridge are synchronized so the initial mists are ridge-sized but they grow as they rise.

It's cool that this is getting scientific attention, but really weird to me that this was some kind of revelation. It's plain as day if you just watch the forest.

I believe it was this phenomenon and more discussed in the CBCs The Nature of Things “What Trees Talk About”.[0] Well worth the time to watch.

[0] https://www.cbc.ca/natureofthings/episodes/what-trees-talk-a...

Ironic that you can synthesize these hydrocarbons from petroleum. Burn 10,000acres of forest, replace it with chemicals made from a barrel of oil sprayed into the atmosphere.

> so we can fix our climate models.

Is there any indication if this discovery will improve or worsen the current outlook? It doesn't seem like the article points in either direction.

While I believe the link between human activities and global warming have been well-established, I still find the certainty of imminent runaway climate that'll turn the Earth into Venus to be counterproductive. Even if it's true, this message just numbs people.

The fact is that to a certain point the Earth has climate balancing mechanisms that we have little to no understanding about. Why do I say this? Because if it didn't, we would already be Venus. The climate on Earth has ranged from ice to the equator to being much warmer than it is even now. So why hasn't this runaway climate change happened in the last 4 billion years?

Now for a long time the standard retort has been the pace of climate change is different now. Not so. Look at Dansgaard-Oeschger ("D-O") cycles [1]:

> One of the most surprising findings was that the shifts from cold stadials to the warm interstadial intervals occurred in a matter of decades, with air temperatures over Greenland rapidly warming 8 to 15°C

This occurred multiple times over the last 100,000 years.

So rather than focus on this doom and gloom scenario, consider that climate change isgoing to kill a lot of people (through famine, flooding, areas becoming uninhabitable and the upheaval from all the resulting migration). Even then, we as a society constantly make tradeoffs of personal convenience where the cost is people dying. Sometimes a lot of people. Even apart from dying, our society cannot exist as it is without the exploitation of the Global South. We as a society have decided we're fine with people people being paid pennies to work themselves to death in death trap factories to make our lives possible.

It's not surprising that trees seed clouds. You can kind of see this in photos of a jungle canopy (eg [2]). The new part is learning how sophisticated this mechanism is. But I guess it makes sense: clouds reflect light and so it becomes a defense mechanism for trees drying out.

[1]: https://www.nature.com/scitable/knowledge/library/abrupt-cli...

[2]: https://www.canopyintheclouds.com/

I don't think there's any climate model that turns Earth into Venus. That's just doomer rhetoric that you see online without any citation.

It’s easier to “raise awareness” than pick up litter or dig holes and plant trees.

This 2004 paper "A new feedback mechanism linking forests, aerosols, and climate" in Atmospheric Chemistry and Physics was the first time I read about this.

https://acp.copernicus.org/articles/4/557/2004/acp-4-557-200...

About 10 years ago I went to the Amazon rainforest to a place where you could climb trees. The host there explained to us that trees made it rain by “sending fairies” up into the clouds - then when he saw our faces he said the fairies were, of course, just chemicals released by the trees

Really fascinating to see a recent article about the scientific research of this phenomenon

Messing with very complex systems and expecting that random odds benefit instead of doom you and all mankind is a bad bet.

And this kind of things gives another hint on how complex the system is, how many players influence and are influenced by it, including not even suspected ones.

We should take into account things that we don’t know that we don’t know when betting big.

Not a revelation at all. If you read the work of Francis Hallé, it is very well explained. Also the communication between trees through released chemicals during fires.

https://en.m.wikipedia.org/wiki/Francis_Hall%C3%A9

Reminds me of this Scandinavian project:

https://innovationorigins.com/en/selected/using-wind-turbine...

So aside from how this affects cloud formation models, could it be used directly to seed clouds if it could be made in large quantities artificially? Probably a dumb question, but I'm not really a meteorologist or atmospheric physicist...

https://archive.ph/1Qnjp

I read an account a few years ago where an orange juice factory in S. America couldn't figure out what to do with the orange peels. Being filthy capitalist swine, they trucked it out to an arid area that was nothing but scrub, and dumped it.

Fast forward 20 years. It turned into a garden that created its own micro-climate. All sorts of vegetation, including trees, was thriving in it, and the area it occupied was slowly expanding.

It boggles the mind what can be done with the incredible amount of food waste humans generate.

Since then, when I eat an orange, I just throw the peels out into the yard.

My city collects food and yard waste. Then sends it to be composted on industrial scale that can handle food scraps. The result is compost that can buy in stores.

I think waste composting should be the standard everywhere. It separates organic waste from landfills where it would turn into methane. Composting produces CO2 but most of the carbon gets sequestered in the soil. I do wonder what should do with the compost when there is a huge supply. Mixing it into farmland to improve the soil might be good idea.

I've looked at clouds from both sides now

From up and down, and still somehow

It's cloud illusions I recall

I really don't know clouds at all

and humans mostly do the opposite, air pollution is preventing rain, sometimes it can fall the week-end when pollution is lower

For me the "value" of a tree is extremely high, as well as plants, insects, worms.., humans values are the bottom of this scale, just after mosquitoes

Are there correlation studies on this? I’m genuinely interested in reading about this.

Tangent - Earthworms are an invasive species in North America[1]

[1] https://en.wikipedia.org/wiki/Invasive_earthworms_of_North_A...

Sort of. Earthworms are a natural species in North America, but in the northern parts of the continent they were wiped out by glaciers ten to twenty thousand years ago.

https://www.smithsonianmag.com/smithsonian-institution/earth...

The entire idea of invasive species is kind of fraught, because organisms migrate over time. Barren volcanic islands will become seeded with life. Past extinction events change the ecological dynamic. Technically, ocean life invaded the land hundreds of millions of years ago. Land bridges open up, continents collide or separate, etc. Humans weren't the only organism to migrate out of one continent onto others.

And the entire idea of species is kind of fraught because once we were all microorganisms?

No. Invasive species are relatively new to the land, they disturbe the existing equilibrium often without any natural predators to hunt them and they wreak havoc.

Like wild boars in USA. Like rabbits in Australia. Like humans on earth.

Barren islands evolved for tens of millions of years in isolation were all over the world until humans built ships.

Earthworms is an entire subclass of animals. There are earthworms native of USA. Other aren't.

Are you sure it's not the other way around? I remember reading Mondays have the sunniest weather because there's less pollution over the weekend.

And also from the article:

>In the sky, aerosol particles attract water vapor or ice. When the tiny wet globs get large enough, they become seeds for clouds. Half of Earth’s cloud cover forms around stuff like sand, salt, soot, smoke, and dust. The other half nucleates around vapors released by living things or machines, like the sulfur dioxide that arises from burning fossil fuels.

> air pollution is preventing rain

Air pollution also causes more rain, changes rain from shallow to severe, and a large host of other effects. It's not simply "air pollution is preventing rain".

A simple example - for ~100 years mankind has used silver iodide to seed clouds to cause rain. Silver iodide would easily be called air pollution. [1]

Here's google scholar - note the large variety of rain and pollution interaction - and most certainly not as simple or negative as you post [2]

[1] https://en.wikipedia.org/wiki/Cloud_seeding

[2] https://scholar.google.com/scholar?hl=en&as_sdt=0,15&q=preci...

obviously talking of the common car traffic and related air pollution

And wrong. Read the research.

all studies agree on "urban areas receive significantly more precipitation at weekends than on weekdays" which was my initial point

the "Inverse relations between amounts of air pollution and orographic precipitation" article seems like an outlier and buzzy paper nothing much more

All studies, huh?

[1] "Daily precipitation records for 219 surface observing stations in the United States for the 42-year period 1951–1992 are investigated for weekly cycles in precipitation. Results indicate that neither the occurrence nor amount of precipitation significantly depends upon the day of the week"

[2] is a highly cited paper, has a good overview of the field, lots of papers, and certainly points out that the claims you're making are not considered statistically valid. They present ~2 dozen papers, show that some claim effect, some do not, rank them by statistical quality, and most interestingly, have a good summary table (Table 2). Use Sci Hub to read the paper. Table 2 makes it completely clear your claims are simply not warranted by the science. The rest of the paper reaches the same conclusion....

"The idea that it rains more on weekends because of weekday pollution is a myth." [3]

If you care to read the literature, you'd find these are not outlier papers. The effects are far more subtle, and much weaker statistically and evidentially, than you are claiming.

[1] https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/200...

[2] "Assessing large-scale weekly cycles in meteorological variables: a review"

[3] https://www.businessinsider.com/does-it-rain-more-on-the-wee...

https://www.google.com/search?q=urban+areas+precipitation+at...

there are maybe some exceptions, but just look at this link and studies are showing the weekend effect is real in urban heat/pollution islands

The top sentence on that search reads "There is no scientific evidence that it rains more often on weekends than on weekdays like Mondays. Weather is determined by a variety of complex atmospheric conditions that have nothing to do with the day of the week. However, the perception that it rains more often on weekends can be attributed to human bias"

I also just listed several decent studies meta studies summarizing a lot of the academic literature, and they seem quite in agreement that the situation is not as simple as you claim. In fact, the top several hits from your search are the studies I posted above.

It's possible that in terms of volume of precipitation, urban areas get as much or more (https://www.udel.edu/udaily/2020/december/mather-lecture-mar....) but the point is the negative impact of human, preventing "good" soft rain, because those precipitation are more intense and rare, so it's causing erosion and the result is just like less precipitation for plants/trees

> humans values are the bottom of this scale, just after mosquitoes

Aren't us humans almost exclusively a net negative, except for a small few? Meaning in most cases to Earth, it's best we didn't exist? We create pollution, waste, consume large amounts of resources that are only a net benefit in some cases to humans.

Now in a cosmic sense, maybe the Universe gains by having life - but who knows

Totally, the other animals that also have negative footprint are pets, farming animals due to their food and care

All other animals are autonomous and participating in the ecosystem

Has any other life form on Earth protected another life form on Earth from extinction? It seems like other life is spending 0 effort maintaining the environment, preventing the extinction of other species that are considered competitors for limited food and limited space.

While I don't disagree with these points, wouldn't this mean some small number like 0.0000001% of all of us humans over humanities entire existence are not a net negative?

The species that evolved in conjunction with those ecosystems don't have to put effort into maintaining those ecosystems. They do it automatically.

In a ruthless way. Cuckoo birds have a mating strategy that would be immoral by human standards. As would that of the praying Mantis

All this is to say humans treat animals better than animals treat one another. We condemn cannibalism, rape and Necrophilia as natural species engage in it. If we observe that behavior in a zoo we actively prevent it. We impose that mortality upon them

humans is not even comparable, responsible of mass-extinction, biomass huge decrease, farm animals conditions are very enviable, captive animals (zoo, pets) neither

they're murdering insects everytime they take a 1.5 tonne vehicle for doing a few kilometers flat, and murdering many others indirectly through pollution, consumption, etc

65 million years ago an asteroid hit the earth, making untold species extinct and causing unimaginable climate change in the span of a few hours. Now, with humans on earth with telescopes and rockets and space-facing radar, we might stand a chance if it happens again. I’d say that counts for _something_.

I don't have the source, it was a few years ago, but there is a positive correlation between particulates and precipitation; however it can take several days for the effect to reach maximum "signal" and due to the movement of air masses the actual precipitation can happen some distance (possibly thousands of miles) from the source of particulates: if it rains (or doesn't rain) on the weekend for you, that might have some correlation to location of the source of particulates in your area.

A related effect would seem to be low sulfur fuel reducing ocean cloud cover (compared to previous fuel). I just saw an interactive map of a study using aircraft cruising altitude to impact cloud formation a few days ago.

Why is this an archive link? The original article is still up; indeed, it's from yesterday: https://www.wired.com/story/a-revelation-about-trees-is-mess...

To get around the Wired.com paywall. They only let you read a limited number of articles for free.

Archive links stand a better chance of continuing to work over time.

We've changed the URL now from https://web.archive.org/web/20230930090902/https://www.wired....

Submitters: "Please submit the original source. If a post reports on something found on another site, submit the latter." - https://news.ycombinator.com/newsguidelines.html

It's fine to post archive links in comments but in general not as top-level submissions. If you've googled around for a current rendition of the article and have satisfied yourself that there really isn't one out there, then it's ok - but otherwise please post the original URL and include an archive link in the thread if you want to.

Why is this not linking directly to the wired article? https://www.wired.com/story/a-revelation-about-trees-is-mess...

We've changed it now.

A great HN feature would be a link to a chatgpt chat, with the contents of the article loaded into the context, summary already generated. Some of these articles are five sentences of interesting information, hidden among five paragraphs of forced human interest.

Reply on news.ycombinator.com