Hacker News

Does the Amazon provide 20% of our oxygen?(yadvindermalhi.org)

313 pointsmchouza posted a month ago226 Comments
226 Comments:
wcunning said a month ago:

The basic gist of the article is found about 1/2 way in:

"First, the phytoplankton in the oceans also photosynthesise [...] Therefore in terms of TOTAL global photosynthesis, photosynthesis in the Amazon contributes around 9%. [...] Second, a bigger point that is often missed is that the Amazon consumes about as much oxygen as it produces."

This reminds me, as we should all be reminded on a regular basis, the bulk of the things you read in the popular press are at best skimming the surface and at worst outright misleading due to grabbing onto one obscuring factoid instead of the most important pieces of information. Per Gell-Mann, I only see this in tech and science reporting, but that makes me really unreasonably suspicious of political reporting, too.

Merovius said 25 days ago:

> This reminds me, as we should all be reminded on a regular basis, the bulk of the things you read in the popular press are at best skimming the surface and at worst outright misleading due to grabbing onto one obscuring factoid instead of the most important pieces of information

FTR, this article is doing exactly that. Like, they a) divert your attention with the CO₂<->O₂ conversion (which doesn't change relative numbers in percentages of photosynthesis at all - you multiply both sides of the equation). And b) then proceeds to pretend that the Amazon eats up most of the Oxygen it produces, but the rest of the world apparently doesn't. Like, if a tree re-metabolizes 40% of the O₂ it produces, then that's also true for the 91% of O₂ produced outside the Amazon, so we still end up with the same 9% figure of all O₂ produced in the Amazon.

The article ends with the "CO₂ emission is more important". Which, again, fair. But Photosynthesis is presumably a pretty important mechanism by which CO₂ is removed from the air. So a reduction of O₂ production is equivalent to a reduction of CO₂ absorption (though you have to multiply with 2.67, don't forget!), which seems to… be a bad thing for CO₂ concentration in the air.

The gist of the article is pretty much "if you don't round and take into account maritime photosynthesis, the Amazon only produces 9% of all O₂". Which is fair. The rest is noise. It doesn't add to the argument and is just fueling the "MSM is bad!" cries…

jefftk said 25 days ago:

The article is making a much stronger claim:

> the net contribution of the Amazon ECOSYSTEM (not just the plants alone) to the world's oxygen is effectively zero

If this is correct, then the entire Amazon could vanish without having any effect on CO₂ levels.

chewbacha said 25 days ago:

It could be correct and still have an impact on CO2 levels as it is still a massive sequester of carbon. Burning it down removes the sequester and adds it to the atmosphere.

Also, just because it doesn’t produce the breathable O2 we need, that doesn’t mean it’s not part of a global system that produces and stabilizes our atmosphere. It actually is responsible for a massive silt run off that feeds the oceanic diatoms that in turn produce half of the worlds breathable O2 and fixes carbon right in the ocean.

This is a case where a literal point is incorrect but it does not decrease the importance of the rainforest to our globe.

dcolkitt said 25 days ago:

Some back of the envelope math... One tree in a tropical rainforest sequesters 50 pounds of carbon. The Amazon contains 390 billion trees. Since industrialization humanity has cumulative released about a trillion tons of carbon. So if the entire Amazon burned down it would increase atmospheric carbon by less than 1%.

This is just a rough estimate, and I'd encourage others to check my calculations. But intuitively this seems correct. Extracting fossil fuels releases all the carbon sequestered by organisms over 100 million+ years. Burning down a rainforest only releases the carbon sequestered by organisms currently living.

I don't see how it wouldn't be possible for fossil fuels not to contain orders of magnitude more carbon than forests. Which is of course why the switch from wood to coal precipitated the industrial revolution.

[1] https://medcraveonline.com/FREIJ/FREIJ-02-00040.pdf [2] http://mentalfloss.com/article/63519/how-many-trees-are-ther... [3] https://ourworldindata.org/co2-and-other-greenhouse-gas-emis...

chewbacha said 25 days ago:

I agree that burning fossil fuels release more CO2 into the atmosphere. I was not trying to imply that the rainforest will halt global warming, obviously it can’t because it’s been there the entire time.

However, I do believe just multiplying trees by weight does not accurately describe what carbon sequestration is. Trees are not the only place carbon is sequestered in a forest. Soil sediment, animals, and other plants also sequester. It’s also a home of biodiversity and nutrient run off that assists other parts of our global ecosystem. In turn, Carbon sequestration occurs over time; and it’s these rich, biodiverse ecosystems that produce the fossil fuels that we are burning, without them the carbon would never sink into the earth as it does.

Eliminating the rainforest halts the engine that cleans the atmosphere and removes the carbon and cools the earth. It would also dump millions of more tones into the atmosphere (even by your calculations). It would also disrupt global food chains which do produce our global breathable oxygen.

I’m not sure what your point is that you are making other than you imply that we don’t need to save the tropics because fossil fuels are worse; but I heartedly disagree with that implication.

dcolkitt said 25 days ago:

> However, I do believe just multiplying trees by weight does not accurately describe what carbon sequestration is.

That's a fair point. The IPCC gives an estimate of 109 tonnes per acre of tropical forest. Which is about an order of magnitude higher than my original estimate.

But even with those numbers, deforestation is basically a rounding error compared to fossil fuel emissions. The Bolsonaro admin has increased deforestation rates by 278%, or an annual rate increase of 4500 sq km. Using the IPCC numbers, that's 110 million tonnes of Carbon per year.

That's less than one week of America's carbon emissions. Less than one day of global carbon emissions. The point is that from a climate standpoint, current rates of deforestation are largely inconsequential compared to fossil fuel emissions. It's almost certainly more effective to spend political and economic capital on energy efficiency and renewables.

shkkmo said 25 days ago:

> Trees are not the only place carbon is sequestered in a forest

Trees are not the only part of the amazonian ecosystem, but I'm pretty sure trees outweigh other parts of the amazonian ecosystem by a significant ratio. I think the calculation probably suffices as a back of the envelope estimation.

> I’m not sure what your point is that you are making other than you imply that we don’t need to save the tropics because fossil fuels are worse; but I heartedly disagree with that implication.

Removing tropical rainforest would be disastrous, but not because of impact on global CO2 levels. (Its effects on CO2 levels would not be helpful but wouldn't be among the worst consequences). Among other reasons, it would significantly alter global weather patterns and cause massive damage to ecosystems across the globe.

I think the point is that even an ecosystem as massive and influential as the amazon can't even make a dent in the amount of CO2 that is being produced by human activity.

mirimir said 25 days ago:

That's actually pretty much true. At least, if it literally "vanished", without releasing biomass carbon back to the atmosphere.

In temperate ecosystems, there's net long-term storage of biomass and nutrients in soil. Mainly roots of dead plants. But also stuff that accumulates faster than it can decompose. Tundra and taiga are extreme examples.

But mature tropical ecosystems are pretty much in equilibrium, with ~zero net impact on the soil or atmosphere. Pretty much all mineral nutrients are locked up. And everything that dies gets recycled very quickly.

mycall said a month ago:

O2/CO2 aside, the Amazon rainforest's biodiversity is unique and has been a source for medical resource. There is more at stake than just breathing.

RcouF1uZ4gsC said a month ago:

I hear this brought up a lot. Can you name a drug that has actually passed all the safety and efficacy trials that has been developed from something in the Amazon?

ramphastidae said a month ago:

Quinine for one. There are many more if you are willing to do five minutes of research: https://www.conservation.org/blog/5-rainforest-species-that-...

darkerside said a month ago:

It's 5 minutes of research if you know what you're looking for. It can be much more if you don't, and you don't know when and where to stop.

BTW, that's kind of the entire point of a site like HN. Experts from different fields (and hobbyists and laypersons) get together and exchange knowledge. Sorry to go on about this, but I've been seeing too many responses saying to go Google things.

mehrdadn said 25 days ago:

> It's 5 minutes of research if you know what you're looking for. It can be much more if you don't, and you don't know when and where to stop.

I know nothing about the topic, but literally just Googled Drugs from the Amazon [1], and the very first example of the very first search result I came across was Quinine. [2]

[1] https://www.google.com/search?source=hp&q=drugs+from+the+ama...

[2] https://www.adventure-life.com/amazon/articles/medicinal-tre...

dredmorbius said 25 days ago:

Even an answer of the form "here's a set from a quick DDG" is more productive, and might even teach the commenter something, as it provides a fixed (even if incorrect) basis for discussion.

Given the option between not commenting at all or offering some variant of JFGI, I'll strongly prefer the former. "You don't have to attend every fight you're invited to", or comment on every post. But if you do, try to land solid punches. Even if you're not Mohammed Ali.

(I've frequently learned things, and more than once entirely changed my mind, in researching to answer comments.)

refurb said 25 days ago:

That first google link is shit.

has been isolated the alkaloid d-turbocuarine, which is used to treat such diseases as multiple sclerosis, Parkinson's disease and other muscular disorders.

It’s a muscle paralyzing agent used in surgery. It’s not use in MS or Parkinson’s.

I wonder what else is wrong in the article.

topmonk said 25 days ago:

Just type into google "drugs developed from amazon forest" and the results appear above the search results right in an answer box.

No need to wag your finger.

RcouF1uZ4gsC said 25 days ago:

My question was specifically about drugs that had passed safety and efficacy trials that were derived from the Amazon. Doing 5 minutes if searching and looking at your links it looks like quinine and curare are two of them. There was some mentions of some potential agents, but none that had made it through full clinical trials to be FDA approved. Quinine was first used for malaria treatment over 400 years ago. Two drugs over 400 years doesn’t seem like a lot.

And it doesn’t seem that it will get higher. My impression of modern pharmaceutical research is that instead of focusing on natural medicinal compounds, it is more focused on discovering the exact mechanisms behind various disease processes and synthesizing molecules that either slow down or speed up key pathways along those processes.

rolltiide said 25 days ago:

> There are many more if you are willing to do five minutes of research

but thats also how you end up on a geocities site about anti vaxxing because big pharma doesn't want you to know about the amazon and yell "exactly, I knew it all along!"

majos said a month ago:

I don't quite get the claim behind the Gell-Mann effect. It assumes that because journalism about physics is inaccurate and oversimplified, journalism about everything else is too.

But why should this be? Physics, and similar hard sciences, are deep and complex fields. There's plenty of math, jargon, and a long literature. Of course inaccurate simplifications happen when writing about it for a popular audience. Add in the weird incentives of mass media and the lack of scientific expertise among most journalists, and it makes sense that popular physics news is not so accurate.

In contrast, other newspaper topics like politics, sports, business, etc. are often literal reporting of what people do. I'm not saying any of these areas is necessarily simple, but they are at the root level about human actors, not abstract quantities that most people have 0 intuition for. So I expect that it's actually easier to do good reporting on those topics.

rayiner said 25 days ago:

Politics and business are incredibly complicated as well. In many ways it’s even harder to do reporting in those areas because there is no expert consensus you can consult. Is lowering corporate taxes better for the economy? There is little consensus. Even reporting “what people did” can be fraught with peril. (E.g. reporting that a company “paid no taxes” without addressing loss carry forwards.) Political and business systems, and in particular complex regulatory regimes like tax policy, are the product of many decades of refinement. Because journalists for the most part are ignorant of that history, they present every policy issue in this sort of context free way, leaning heavily on narrative and emotion to make up for their shallow understanding of the actual mechanics of what they’re writing about.

untog said 25 days ago:

I think where the comparison breaks down is that the laws of physics are the laws of physics. Reporting on them doesn't change them. But politics lives in the same world as reporting. It is shaped by it, politicians respond to it. So the Gell-Mann effect isn't quite accurate in that situation. Journalists do know the political world deeply because for better or worse they're involved in shaping it.

aetherson said 25 days ago:

I don't think it follows that people must necessarily know a lot about things they have a relatively large influence over.

xmprt said a month ago:

Your comment illustrates the point even more in my opinion. You understand more about physics than politics, sports, and business, and so you're able to see how journalists can get it wrong. However, if you actually dived into the world of sports and similar fields about "human actors" there's a lot of interpersonal relations and complexity that can't be described in a 500 word article. If journalists were just reporting about the "what" then physics would be just like reporting sports scores if you just copy the result. When you try to explain the "how" and "why" then all the complexity that you described about physics applies to sports.

majos said 25 days ago:

Maybe my original point was vague: I'm arguing that the "what" is simpler when human actors are involved. Person x said this, did this, accomplished that. The story is for the most part straightforward and understandable. And a lot of the reporting in these areas is just "what".

But people don't even have a good handle on the "what" of a lot of science (what are these new particles? what is p vs np?) which is why we get all these analogical half understandings.

wcunning said 25 days ago:

I think the bigger question in a lot of human centric things is the "why" -- why did that head of state say that thing? Why does this company avoid that regulation? Why do people complain when this tax credit goes away? It's not reasonable to stop with the "what" in many situations. Or alternatively, the comparison to physics should be an article saying that the what is the spin of a single electron in an experiment, even though the experiment is about gravity -- missing the point entirely.

And backtracking slightly to my grandparent comment, Gell-Mann was coined by Michael Creighton who in the same quote compared Murray Gell-Mann's knowledge of physics to Creighton's knowledge of show business. The "what you know well enough to spot errors" can be anything as can the "what you blindly trust the reporter on out of your own ignorance."

Erlich_Bachman said 25 days ago:

> I'm arguing that the "what" is simpler when human actors are involved.

Where would you get that idea? It is definitely the other way around.

In hard sciences at least you can easily construct experiments and find out truths with time, which while complex, are basically predictable. In human sciences everything is much more complex and chaotic effects and problems with definitions and inherent unpredictability of humans make everything more complicated.

liability said a month ago:

> In contrast, other newspaper topics like politics, sports, business, etc. are often literal reporting of what people do.

I was once in a local paper for my participation in a sports team. Well, my picture was. The name given to me in the article and caption was fabricated. Such a name didn't even belong to anybody else in my school, let alone on the same team!

I assume the 'reporter' was too drunk to remember my name and too embarassed to ask somebody, so he just made one up.

DoreenMichele said 25 days ago:

I was interviewed via email while still homeless. They assumed I was male without asking, then just made up quotes. Because the interview was by email, I have a written record of what I actually said, so I know it was outright fabricated and not some kind of misheard/misunderstood thing.

I sort of understand the misgendering. Most visible street people are male. But the fabricated quote made me feel like "They think they can just do anything they want because I'm so poor." That felt like intentionally shitty behavior.

zaroth said 25 days ago:

Don't worry, they do the same thing to everyone, including the President. Making up quotes, that is.

DoreenMichele said 25 days ago:

It's still shitty. General lack of ethics and honesty is not some moral high ground that sits above mere classism and contempt for the poor and presumed powerless.

gamblor956 said a month ago:

That is extremely unusual since besides generally require release forms from people in the pictures they run.

Monroe13 said a month ago:

In the US at least, no release form is required of those pictured in a news article.

gamblor956 said 24 days ago:

In the US at least, a release form is required of those pictured in a news article by name for articles published by the AP or any major city newspaper like the NYT, Chicago Tribune, WaPo, or LA Times...

Monroe13 said 23 days ago:

Nope, even the big publications do not use or need release forms for photos in news reporting.

If you are in public and the photo is “newsworthy” your image can be printed in a newspaper without your consent.

“Use of someone's name or likeness for news reporting and other expressive purposes is not exploitative, so long as there is a reasonable relationship between the use of the plaintiff's identity and a matter of legitimate public interest.” - http://www.dmlp.org/legal-guide/using-name-or-likeness-anoth...

doubleunplussed said 25 days ago:

There's a saying for this. Something about a sweet summer child.

kirsebaer said 25 days ago:

When you read news from something that you personally have been involved in, you will notice journalists simplify and often get things a bit confused.

Like, when a journalist quotes you in print, it is often not a real direct quote, but rather the journalists interpretation of what you said (which can be way off). Always insist to "check quotes" or you could get a surprise when you read your interview.

icelancer said a month ago:

>> In contrast, other newspaper topics like politics, sports, business, etc. are often literal reporting of what people do

This comment should be preserved for all time and cited in the Gell-Mann Effect entry. Do you really think physics is infinitely more complicated than finance or politics?

mattkrause said a month ago:

I'm not sure about that specifically, but reporting on politics is much closer to the paper's core competency.

The paper runs articles on politics every single day. The characters and issues don't change too quickly: Quimby was the mayor last week; next week, he'll be the same mayor, dogged by the same scandals and trying to enact the same politics too. A lot of the facts are easy to check, if someone cared to do so. The reporters may have a background in political science or history, or something somewhat related.

In contrast, the science section is pretty small. Maybe it runs once a week and has one or two main reporters, who cover everything from Astronomy to Zoology. No one has a background in all of that, and many reporters don't have a technical background at all. You can try to fact check it, but the experts themselves don't always agree and it's hard to tell whether Dr. So-and-So is really an expert on the topic anyway.

And, despite all that, the science reporting I see does a pretty good job. One of my papers got a bit of media coverage, and pretty much everyone got the broad strokes right. One place made me sound a little too exuberant about the immediate ramifications; another made me sound a bit too negative, but neither was egregiously bad.

umeshunni said 25 days ago:

> reporting on politics is much closer to the paper's core competency.

And despite this, most of the media got the two of the most significant political happenings of the last 5 years (US elections and Brexit) completely wrong.

verall said 25 days ago:

Comments like this are great.

By saying "most of media gets it wrong" without any examples, everyone agrees, and noone needs to think about what the media said or what happened at all. Everyone reading can be right and everyone else can be wrong at the same time.

Less snarkily - what media narrative are you referencing specifically? What do you believe occured instead? There was much media covering many angles on both of these issues.

mattkrause said 24 days ago:

I agree that they incorrectly predicted future events, but no one should be able to that with absolute certainty. Past events are, of course, much easier to report accurately.

untog said 25 days ago:

What does "got wrong" mean in this context, though? People said the media got those things wrong because they said "90% chance Clinton wins" and Trump won. But that's why they said 90%, not 100%. It feels as though the concept of probabilities is either misunderstood or willfully ignored to score points.

jchallis said 25 days ago:

In the initial formulation of the Gell-Mann effect, Michael Crichton noted that the coverage of show business was equally simplified.

From discussions with my wife, who is board certified in infectious diseases, newspaper coverage of the following topics are simplified to the point of losing the main point: antimicrobial resistance, any tropical disease from malaria to Ebola, organ rejection.

I think the problem is universal not specific.

karmakaze said 25 days ago:

Any decent news report will of course have coverage of the literal facts, this will also be overshadowed by interpretation of the meaning of those facts. Any dry reporting which only present the facts without a hint as to how the reader should be reacting to those facts is unpopular and will be read by negligible few. It starts right from the headline that takes a view one way or the other. A number isn't presented without an adjective.

aaron695 said a month ago:

> It assumes that because journalism about physics is inaccurate and oversimplified

No, it's about entertainment and then other fields for other people since Michael Crichton named it. He specifically says minimum entertainment for himself as the creator.

He named it after Gell-Mann as a kinda in joke.

twic said a month ago:

If someone asked me what i thought the main problem with comments on Hacker News was, i would direct them to this comment.

strainer said 25 days ago:

The blogged claim that Amazon "consumes about as much oxygen as it produces" is not sourced and the piece seems to fly in the face of professional work on the subject. eg: "The global oxygen budget and its future projection" [1]

> Fig. 4 summarizes the annual averaged global O2 budget from year 1990 to 2005, with the mass of O2 in gigatonnes (Gt) listed in each sink and for each process mentioned above (see Section 2.5). The inputs of O2 to the atmosphere by land and outgassing from oceans are quantified as 16.01 and 1.74 Gt/a, respectively. ....

[1] https://www.sciencedirect.com/science/article/pii/S209592731...

BurningFrog said 25 days ago:

Let's demystify how plants "produce oxygen".

They do it by splitting CO₂ molecules. The oxygen part (O₂) goes into the air, and the carbon (C) part becomes the plant.

So for the Amazon to continually produce surplus oxygen to the atmosphere, it must also continually produce an ever expanding amount of plant material ("wood") that would form an ever growing pile there.

This is not happening. Because forests don't produce surplus oxygen. Our atmosphere doesn't work that way.

https://en.wikipedia.org/wiki/Photosynthesis

EB66 said 25 days ago:

> This is not happening. Because forests don't produce surplus oxygen. Our atmosphere doesn't work that way.

This is just plain wrong. The blogger is completely wrong on this point as well.

In normal atmosphere conditions, photosynthesis does result in net oxygen gain. Plants do require oxygen for respiration, but they require far less oxygen than what they produce during photosynthesis. Furthermore, at night when there's no light, plants do absorb oxygen and give off carbon dioxide in order to continue respiration -- but the amount of oxygen given off during the day is typically ten times greater than the quantity of oxygen consumed at night.

> This reminds me, as we should all be reminded on a regular basis, the bulk of the things you read in the popular press are at best skimming the surface and at worst outright misleading due to grabbing onto one obscuring factoid instead of the most important pieces of information.

Similarly, we should all be reminded that when skimming blogs and comments you're likely to come across misleading and inaccurate content. Scientifically inaccurate content like this gets posted on HN and blindly upvoted all the time.

shkkmo said 25 days ago:

> The blogger is completely wrong on this point as well.

I think you may not have read the article closely enough:

>> Plants produce oxygen through photosynthesis (green arrow). However, the the same plants consume the equivalent of over half the oxygen they produce in their own respiration ... my own team's research suggests this is more like 60%

>> The remaining 40% of the Amazon oxygen budget is consumed mainly by microbes breaking down the dead leaves and wood of the rainforest, a natural process called heterotrophic respiration

> Similarly, we should all be reminded that when skimming blogs and comments you're likely to come across misleading and inaccurate content

The "blogger" who wrote this article is "Professor of Ecosystem Science, University of Oxford" and "Founding Director, Oxford Centre for Tropical Forests" and probably knows more about this than you or I. This is not a peer reviewed paper, but it is probably more accurate than science journalism by a non-ecologist on this topic.

strainer said 25 days ago:

> my own team's research suggests this is more like 60%

My point was he hasn't cited that research - if it is concluded ? published? reviewed?

He seems to be just having a technical rant about a contextual phrase while giving the impression that forests in general, or at least the amazon or equatorial forests do not help maintain the atmospheres oxygen content. That would certainly be a maveric proposition at this stage in Earth sciences.

shkkmo said 25 days ago:

> My point was he hasn't cited that research - if it is concluded ? published? reviewed?

I am far more willing to take the word of an established and respected expert who understand the subject mater than a random internet person with a poorly contextualized citation. You can find the author's published papers on this and related subjects quite easily at the top of the article.

> He seems to be just having a technical rant about a contextual phrase while giving the impression that forests in general, or at least the amazon or equatorial forests do not help maintain the atmospheres oxygen content. That would certainly be a maverick proposition at this stage in Earth sciences.

He is a scientist clarifying a technical subject that has been being misconstrued. There has already been plenty of damage done by people throwing around fake facts and pictures.

strainer said 25 days ago:

The problem is I feel that he has confused understanding of the subject here rather than clarifying it, which is an easy thing for anybody to do in a conversational article.

Here is a recent work[1] which substantiates matters that Amazons practical involvement in the planets atmospheric oxygen/carbon levels is really not as the professor felt like putting it as "effectively zero".

> Abstract: The response of the Earth’s land surface to increasing levels of atmospheric CO2 and a changing climate provide important feedbacks on future greenhouse warming6,7. One of the largest ecosystem carbon pools on Earth is the Amazon forest, storing around 150–200 Pg C in living biomass and soils8. Earlier studies based on forest inventories in the Amazon Basin showed the tropical forest here to be acting as a strong carbon sink with an estimated annual uptake of 0.42–0.65 Pg C yr−1 for 1990–2007, around 25% of the residual terrestrial carbon sink3,4. There is, however, substantial uncertainty as to how the Amazon forest will respond to future climatic and atmospheric composition changes. .... Here we analyse the longest and largest spatially distributed time series of forest dynamics for tropical South America. .... Our data show that mature forests continued to act as a biomass sink from 1983 to 2011.5, but also reveal a long-term decline in the net rate of biomass increase throughout the census period. The decline in net biomass change is due to a strong long-term increase in mortality rates, and occurred despite a long-term increase in productivity. While mortality increased throughout the period, productivity increases have recently stalled showing no significant trend since 2000. ....

[1]https://www.nature.com/articles/nature14283

Published in Nature: 18 March 2015 : "Long-term decline of the Amazon carbon sink"

EB66 said 25 days ago:

> The problem is I feel that he has confused understanding of the subject here rather than clarifying it, which is an easy thing for anybody to do in a conversational article.

I couldn't agree more. A bunch of people are coming away from reading that article believing that forests have no impact on global carbon sequestration and oxygen production. In attempting to make a contrarian technical point and refute mass media figures, the author has done a disservice to furthering public understanding of the issue.

Sure, a mature forest can come into equilibrium with regard to carbon/oxygen production and consumption. A forest could even be a net contributor of atmospheric carbon by means of an insect or fungus overpopulation. However:

1. Studies show that's not true for the Amazon rainforest (annually it is still a carbon sink).

2. Over the lifetime of the forest the effect is clearly a massive gain in oxygen and massive sequestration of carbon as evidenced by all the biomass (e.g., trees) and dirt you find in forests.

shkkmo said 25 days ago:

> A bunch of people are coming away from reading that article believing that forests have no impact on global carbon sequestration and oxygen production.

If you were really concerned about people misunderstanding the article, you would not make up claims and attribute them to the author. Instead you would quote the relevant parts of the article to demonstrate what is actually being said.

The author in no way claims that the Amazon is in equilibrium, (probably because as one of the foremost global experts on rainforest carbon cycles, he knows it isn't.)

Edit:

The claims are quite specific:

1) The amazon provides ~9% of the global O2 production.

2) The amazon consumes most of the O2 it produces through tree metabolism and wood decomposition.

3) There is way, way more O2 in the atmosphere than CO2 so the effects all human activity (or ecosystems) on global O2 levels are miniscule compared to their effect on global CO2 levels.

Burning down the entire amazon rainforest would be a bad for a number of reasons (release of CO2, changes in global weather patterns, loss of bio-diversity, etc), but impact on global atmospheric O2 levels is NOT one of those reasons.

Fear mongering about a non-issue with made up facts only serves to provide ammunition to anti-science skeptics.

EB66 said 24 days ago:

> If you were really concerned about people misunderstanding the article, you would not make up claims and attribute them to the author. Instead you would quote the relevant parts of the article to demonstrate what is actually being said.

What on Earth are you referring to?

> The author in no way claims that the Amazon is in equilibrium

Yes he does. As I already explained to you, the author asserts that the O2 produced by the Amazon rainforest ecosystem is equal to the amount of O2 consumed by the Amazon rainforest ecosystem -- that is a perfect example of what it means to be in equilibrium. He literally says it in big bold letters:

> the net contribution of the Amazon ECOSYSTEM (not just the plants alone) to the world's oxygen is effectively zero.

Did he use the word equilibrium? No. Did he describe an equilibrium? Yes!

I am done arguing with you on this point -- it has truly devolved into semantics and has become unnecessarily inflammatory. At this point all I can do is refer you to a dictionary.

> Fear mongering about a non-issue with made up facts only serves to provide ammunition to anti-science skeptics.

Fear mongering? Now you've truly lost me. If asserting that forests net sequester carbon and produce O2 makes me a fear monger, then I'm guilty as charged...

shkkmo said 24 days ago:

> At this point all I can do is refer you to a dictionary.

The paper you cited as "disproving" the author's argument for "prefect equilibrium" was co-authored by the author.

Indeed, in the comments on the article, the author explains further:

>> [net carbon sequestration] is not related to the total amount of photosynthesis, but to where organic matter is being buried and removed from atmosphere and biosphere. This occurs in places like swamps, peat bogs and in particular deep ocean sediments. Material from the Amazon probably plays some role in this (e.g. organic material being swept out into the ocean and being buried in deep sediment), but this process is not strongly related to the amount of photosynthesis in any given area. I suspect the burial of a tiny fraction ocean plankton in deep sediments play a dominant role here.

> Fear mongering? Now you've truly lost me. If asserting that forests net sequester carbon and produce O2 makes me a fear monger, then I'm guilty as charged...

Sorry, I am talking about making claims like "the amazon produces 20% of our oxygen." and I was doing so to justify what you called "nitpicking"

The point I was trying to make (and clearly did a poor job with) is summarized by the author in one of his responses to attacks like yours and strainers:

>> No ecosystem scientist I have spoken disagrees with the science in this post: it simply highlights a long-established scientific understanding that oxygen angle is a myth. Just like no serious climate scientist denies the seriousness and importance of human-caused made climate change. If you choose to be selective about which science to choose to hear you fall into the same trap as the climate deniers, construct your own alternative facts universe and you betray your scientific training. The also open yourself the other, more accurate arguments being discredited as a package when the scientific truth emerges

shkkmo said 25 days ago:

What does that article show? Can you explain how that has any relavance to the impact on global oxygen levels?

Why are you still conflating O2 and CO2?

Edit: You do realize that "Y. Malhi", one of that authors of that paper, is the same "YADVINDER MALHI" who wrote this blog post.

strainer said 24 days ago:

> Why are you still conflating O2 and CO2?

That should be obvious. Any evidence of amazon sequestering carbon is evidence of amazon liberating oxygen. If you cant bear that in mind you have been distracted by the artificial separation proposed here, between "a strong carbon sink" sinking carbon and the respiring of O2, they are very effectively both expressions of the same process.

> one of that authors of that paper, is the same "YADVINDER MALHI" who wrote this blog post

Correct and it puts into stark contrast the co-authors private blog advice that "the net contribution of the Amazon ECOSYSTEM (authors emphasis) to the world's oxygen is effectively zero". That misjudged statement which is even highlighted in the article now, is in plain contradiction to that paper he took part in, which is also about the Amazon ECOSYSTEM and the Amazon can not physically be "a strong carbon sink" and at the same time have zero contribution to the worlds atmospheric oxygen system.

The claim is wrong, and hangs only on the ambiguities of what "effectively zero" could be argued to mean that is in reality documented to be very far from zero indeed.

The Amazon has been known for decades as great "lung" of the planet, SINKING Carbon and RELEASING O2. Malhi has himself taken part in work which describes it "greatly" doing so. If its personal credentials you put faith in you could regard Sir David Attenboroughs describing it the same, for many years, in finished and award winning works, as opposed to a professors conversational web article.

Malhi's advisory 9% figure (that is then subsequently reduced to zero?!) is not even necessarily more final or uncontestable as the supposedly terrible global media outbreak of 20% reports. And since (even that work Mahli took part in reveals) that the amazon is recently in serious flux, such figures are technically speaking conditional.

The point of publicity figure is to be defensible and educate the fact that the Amazon has had and can have major effects on the atmospheres important constituents. That whether it is currently in equilibrium or a great carbon sink or grave carbon emitter - is a very grave matter because by its size and history it is capable of all those things.

shkkmo said 24 days ago:

> they are very effectively both expressions of the same process.

But the effects on global atmospheric composition are not equivalent as has already been explained to you. The fact that you seem to choose to deliberately not understand this does not speak well of you.

> The claim is wrong, and hangs only on the ambiguities of what "effectively zero" could be argued to mean that is in reality documented to be very far from zero indeed.

There are no ambiguities, the caveats of that statement are quite clearly stated in the article.

> Malhi's advisory 9% figure (that is then subsequently reduced to zero?!) is not even necessarily more final or uncontestable as the supposedly terrible global media outbreak of 20% reports.

Nobody ever said it was final or uncontestable (that's not how science works). It is a fairly rough estimation, but even as such it is FAR more accurate and its precision is sufficient for popular discussion.

> The point of publicity figure is to be defensible and educate the fact that the Amazon has had and can have major effects on the atmospheres important constituents. That whether it is currently in equilibrium or a great carbon sink or grave carbon emitter - is a very grave matter because by its size and history it is capable of all those things.

Neither I nor the author dispute the importance of the amazon. What is disputed is the bad science that is being spread by the well-intentioned but misinformed.

Atmospheric O2 levels are not a problem, atmospheric CO2 levels are.

What do you think you are accomplishing by attacking environmental scientists and spreading misinformation? Are you really trying to help spread accurate knowledge about climate change? How does this help with that?

strainer said 22 days ago:

Please I have not attacked the professor at all. I have "attacked" an article which has you calling a statement which in all likelihood originates from the advice of an earth scientist > "bad science" and "mis-information" and has you defending the claim that the amazon ecosystems contribution to atmospheric oxygen "effectively zero" And that practically extends to co2 - any caveats are in fact in contradiction to the professors advice that fires and organisms use up all the produced oxygen. But we've already gone through that and are talking past each other now.

nec4b said 22 days ago:

The blogs author is a co-author of the article you linked.

EB66 said 25 days ago:

> I think you may not have read the article closely enough

I did read the article closely :)

>> Plants produce oxygen through photosynthesis (green arrow). However, the the same plants consume the equivalent of over half the oxygen they produce in their own respiration ... my own team's research suggests this is more like 60%

>> The remaining 40% of the Amazon oxygen budget is consumed mainly by microbes breaking down the dead leaves and wood of the rainforest, a natural process called heterotrophic respiration

The author is stating that the Amazon rainforest is in perfect equilibrium without citing any studies or evidence. There are plenty of studies that indicate otherwise, such as this 30 year survey involving 100 researchers: https://www.nature.com/articles/nature14283

> While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation.

But even if we accept the author's argument that today the Amazon is in perfect equilibrium -- I think it was misleading of the author not to clarify that in order for any forest to grow, it must be a net carbon sink and net oxygen producer up to that point in the forest's lifetime.

Now the comment that I originally replied to said something different. That comment argued that forests cannot be net producers of oxygen because there aren't "ever growing [piles of wood]" and then he provided the Wikipedia article for photosynthesis as evidence supporting that. That's wrong as I explained above.

You can have forests that are net carbon sinks and net producers of oxygen and you don't need "ever growing [piles of wood]" in order for that to happen.

shkkmo said 25 days ago:

> The author is arguing that the Amazon rainforest is in perfect equilibrium without citing any studies or evidence

The author argued no such thing, You are making up claims adn attributing them to the author, so perhaps an even closer reading of the blog post would be beneficial.

>> So, in all practical terms, the net contribution of the Amazon ECOSYSTEM (not just the plants alone) to the world's oxygen is effectively zero. The same is pretty much true of any ecosystem on Earth, at least on the timescales that are relevant to humans (less than millions of years).

The paper you cited is talking about carbon dioxide, not oxygen. The net effect on global O2 levels of carbon sequestration is minimal and not significant on human time scales. That same carbon sequestration has a significant impact on global CO2 because there is much less CO2 in the atmosphere.

EB66 said 25 days ago:

> The author argued no such thing, You are making up claims adn attributing them to the author, so perhaps an even closer reading of the blog post would be beneficial.

Please go read the article again. That's exactly what he's saying. He is saying that Amazon rainforest O2 production and consumption are in equilibrium.

> The paper you cited is talking about carbon dioxide, not oxygen. The net effect on global O2 levels of carbon sequestration is minimal and not significant on human time scales. That same carbon sequestration has a significant impact on global CO2 because there is much less CO2 in the atmosphere.

For heaven's sake, please read the study. If you'd rather not read the study, then just Google until you find a satisfactory source that explains that net O2 production and net CO2 sequestration strongly correlate with one another.

shkkmo said 25 days ago:

> He is saying that Amazon rainforest O2 production and consumption are in equilibrium.

where?

> net O2 production and net CO2 sequestration strongly correlate with one another.

yes, but we have ~500 times more O2 than CO2 in the atmosphere so the effects on atmospheric composition are not anywhere close to equivalent.

edit: Let me put it another way. We have so much oxygen that if we were to use any significant amount (say 1%) of that oxygen burning sequestered carbon (rainforests, oil, etc) we would have increased the carbon dioxide in the atmosphere by something like ~2000% (and would already be totally screwed in many, many ways)

said 25 days ago:
[deleted]
EB66 said 25 days ago:

I think you need to look up the definition for "equilibrium" and then re-read the article once more...

Either way I'm done with this tangent.

shkkmo said 25 days ago:

> The author is stating that the Amazon rainforest is in perfect equilibrium without citing any studies or evidence. There are plenty of studies that indicate otherwise, such as this 30 year survey involving 100 researchers: https://www.nature.com/articles/nature14283

Y. Malhi, one of the authors of that paper, is also the author of this blog post. That makes sense since he a preeminent rainforest ecologist who publishes lots of papers on the carbon cycle.

EB66 said 24 days ago:

Yes, you also pointed out this fact up above in the comment chain as well. And as @strainer pointed out, it leaves us with more questions than answers. Specifically: how could he have participated in the study but publish a blog post that contradicts the primary conclusions of the study?

shkkmo said 24 days ago:

> how could he have participated in the study but publish a blog post that contradicts the primary conclusions of the study?

Short answer: Because the article doesn't contradict the study at all.

1) The rainforest is a carbon sink: It holds carbon that would otherwise be present in the atmosphere as CO2.

2) The rainforest is currently a net carbon sink: As an ecosystem it takes in more CO2 than it releases.

3) The rainforest (like most ecosystems) operates fairly close to equilibrium: The amounts of CO2/O2 consumed and produced tend to be pretty close.

4) Major ecological net carbon sinks depend less on the amount of photosynthesis in the ecosystem than they do on the sequestration of bio-matter into the ground.

5) There is ~500x more O2 than CO2 in the atmosphere. This means that the effects of the carbon cycle on atmospheric O2 are far less pronounced than on CO2.

6) net oxygen production of the amazon is effectively 0 (millions of years before a significant impact) because of 5) and 3)

In what way do any of these points contradict eachother?

The major reason (carbon cycle related, excluding biodiversity & global weather patterns & cooling etc) to care about about the amazon is to avoid releasing the CO2 already there. Purely in terms of net carbon sinking ecosystems, we should be paying more attention to our oceans as they do a much better job of sequestering that carbon into the ground.

Oxygen in the atmosphere is simply not an issue because we have so much of it.

dangxiaopin said 25 days ago:

Why bother arguing with him. He has made an ideological statement "the blogger is wrong" at the beginning. No scientific argument starts with "the author is completely wrong". They start from constructive arguments, which may prove or refute prior arguments. You are trying to argue to an ideologue, not a scientist, which is futile.

BurningFrog said 25 days ago:

A single plant does produce oxygen while it's alive, and the carbon is bound in its growing body.

But that carbon is all released back as it decomposes after its death.

On a "whole forest/whole year" perspective, there is normally an equal mass of plants growing and being decomposed, and thus the net oxygen effect is zero.

EB66 said 25 days ago:

> But that carbon is all released back as it decomposes after its death.

> On a "whole forest/whole year" perspective, there is normally an equal mass of plants growing and being decomposed, and thus the net oxygen effect is zero.

Sure, if you're talking about a timespan of one hour, one month, one year, etc then it's definitely possible for biological processes in a forest to expel carbon in the form of CO2 in equal volumes that were sequestered by plants. You could even have an overpopulation of some kind of insect or fungus cause a forest to temporarily become a net contributor of atmospheric carbon.

But over the lifetime over the forest, the net effect is obviously massive CO2 sequestration and massive O2 production. If the net carbon impact was zero over the lifetime of a forest, then forests would have no soil. But we know that not to be the case. Forests grow, they accumulate soil, etc.

Despite constant heavy rains and erosion, soil in the Amazon rainforest is often several meters deep and spans an area of over 2 million square miles. That's a lot of carbon sequestration!

BurningFrog said 25 days ago:

I agree that for a "startup" forest, there will be an accumulation of soil.

I assume it reaches an equilibrium after some time, and that the Amazon soil has remained the same "several meters" deep for many millions years.

But I'll admit I don't know that, and you may have a valid point. If real, this effect has to be quite small though.

EB66 said 25 days ago:

> I assume it reaches an equilibrium after some time

Yep definitely and in part because CO2 only makes up ~0.04% of our atmosphere. Photosynthesis processes slow when CO2 levels fall and increase when CO2 levels rise. But as well as know atmospheric CO2 levels are rapidly on the rise and is outstripping the ability of large forests to sequester it.

said 25 days ago:
[deleted]
nearbuy said 25 days ago:

Then where is the carbon going?

EB66 said 25 days ago:

We're talking about oxygen production. Not carbon sequestration.

Regarding sequestration: the carbon goes into the trunk, branches, roots and leaves of the tree. Leaves fall off the tree, rot and become soil. The tree eventually dies, rots and becomes soil.

Some carbon will be given off by various decomposition processes, but the overall net effect is by far a carbon sink.

nearbuy said 25 days ago:

> We're talking about oxygen production. Not carbon sequestration.

BurningFrog said the carbon from CO2 goes into plants. Since plant matter isn't accumulating, carbon can't be accumulating, and therefore oxygen can't either. You replied, "This is just plain wrong".

So you're saying the part that is sequestered goes into the soil. That means some significant fraction of the 20 billion tonnes of carbon the Amazon photosynthesizes each year is turning in to soil. You're claiming the amount of soil increases by this amount each year, correct?

EB66 said 25 days ago:

> That means some significant fraction of the 20 billion tonnes of carbon the Amazon photosynthesizes each year is turning in to soil.

Correct. That fraction is obviously reduced when the forest is burned.

nearbuy said 25 days ago:

Then why is the soil layer in the Amazon only about a meter deep after millions of years of carbon sequestration? The rainforest photosynthesizes about 3 kg of carbon per square meter per year.

EB66 said 25 days ago:

The soil is not only a meter deep. In most places it's several meters deep and it's that deep despite constant heavy rains and erosion.

The soil does not need to be millions of meters deep in order for the forest to be both a net carbon sink and net positive oxygen producer -- it can slowly acrue over time.

And even if biological respiration processes in the forest began to equal carbon sequestration processes -- the forest would still be a massive carbon sink over its lifetime given the massive quantites of plant matter and soil present.

nearbuy said 24 days ago:

It's about a meter deep on average, but it's such a moot point to quibble over because it's too low by a factor of about 100,000. If it were 100 meters deep, we'd still have to answer the same question.

Yes, the rainforest has been a massive carbon sink over its 30+ million year lifetime - because of the carbon it sequestered while it was first growing and expanding.

Yes, it could be producing very, very tiny amounts amounts of oxygen each year so that the rise in soil level isn't noticeable. If the rainforest was still slowly sequestering carbon in soil at a rate of about 1 meter of soil depth per 30 million years, then you're talking about it sequestering about 0.00005% of the carbon it captures through photosynthesis. If you're calling the article "completely wrong" over that, I'm not sure what to say.

And it's not just the yearly rate of oxygen production that must be negligible. The total oxygen produced over the Amazon's lifetime is negligible. As the article points out, if you burned the entire Amazon rainforest, releasing all the sequestered carbon, it would only decrease atmospheric oxygen from about 20.95% to 20.93%.

baq said 25 days ago:

Bacteria and fungus eat the rest? Consider the Azolla event where dead plant material sank into very salty and oxygen poor water, which left several meters of carbon on the bottom of the polar ocean after 800k years.

nearbuy said 25 days ago:

If fungus or aerobic bacteria eat it, then the Amazon doesn't produce surplus oxygen from it. Eating involves recombining the carbon with oxygen into CO2.

The biomass of the Amazon is not, for the most part, sinking into very salty water.

Ericson2314 said 25 days ago:

I assume the Amazon and it's tributaries wash most of it away.

nearbuy said 25 days ago:

Most of the soil is kilometers away from the nearest tributary. And it wouldn't explain why it washes away everything except for the last 1 meter of soil. Or why the organic matter wouldn't re-enter the food chain once it reached the ocean, thereby recapturing the oxygen.

If 3kg of carbon sequestration per year per square meter were accumulating as soil, and the rainforest has existed at least 30 million years, the soil would be over 2,000,000 meters deep (with rich organic soil being about 9% carbon). If even 1% of the carbon captured through photosynthesis was sequestered in soil, we should still have much, much deeper soil.

atoav said 25 days ago:

Into the plant? Btw. you can easily test this yourself in a closed glas sphere.

PeterisP said 25 days ago:

Exactly, it goes into the plant, and is then released as the plant decomposes - so in a stable rainforest, where the total plant mass isn't increasing, the new plants growing (creating O2 and absorbing CO2) is fully balanced by old plants decomposing or burning (absorbing O2 and creating CO2); so there's no net creation of O2.

varjag said 25 days ago:

That would be true only if you always burn 100% of biomass, which doesn't happen. Carbon gets sequestered into soil, and partly consumed by insects and animals up the food chain.

All carbon in your body was once sequestered by plants.

PeterisP said 25 days ago:

The point is that in a stable rainforest the amount of biomass isn't growing, so you obviously do burn/decompose 100% of the newly created biomass - otherwise the amount of biomass would have grown. Carbon gets sequestered into the soil in cases where soil is being enriched and is "growing in size" (for example, when a previously barren place gets forested) but in a stable, centuries-old rainforest the soil amount really isn't increasing - so as much as gets sequestered, gets released by decomposition.

As the total biomass of insects isn't growing, the carbon they consume is balanced by the carbon released by decomposition of (otherwise) unconsumed insects; the same applies for animals up the food chain - if at the end of 2019 the total weight of insects and animals in the Amazon is not larger than at the end of 1919, then zero carbon has been sequestered in these insects and animals over a hundred years.

nearbuy said 25 days ago:

I meant overall in the long term, in response to EB66 saying BurningFrog is wrong.

The plants can't be net collecting carbon each year unless the Amazon contains more and more plant matter each year.

strainer said 25 days ago:

Into the amazon river and out to sea basically. Rain will wash a lot of matter that way.

navigatesol said 25 days ago:

>The blogger is completely wrong on this point as well.

Classic HackerNews, right here.

His CV is public...and extensive.

>Scientifically inaccurate content

I'm sure Dr. Malhi'd be more than happy to debate you on the subject. Go post your arguments on his blog.

strainer said 25 days ago:

If forests did not then some other body of plant mass would have to - erosion and weathering of rocks takes a lot of oxygen out of the atmosphere, and this needs replaced by biology by photosynthesis. In the long term this is the reason the Earth needs to "breathe", and plants are how it has done so. Plants die and are eaten by ranging animals, dispersing their material, creating soils and eventually sediments. This is a long cycle through which carbon is returned to ground, sometimes to metamorphic rock.

It takes place at a lower intensity than our burning of fossil material and forests in recent history. Regrowing forest, usefully captures carbon and releases oxygen more rapidly than mature forest, but of course not rapidly enough to make up for burning them down.

mirimir said 25 days ago:

The paper that you cite is talking about small changes.

> Under the Representative Concentration Pathways (RCPs) RCP8.5 scenario, approximately 100Gt (gigatonnes) of O2 would be removed from the atmosphere per year until 2100, and the O2 concentration will decrease from its current level of 20.946% to 20.825%.

    2018  209460 ppm
    2100  208250 ppm
That's 15 ppm per year.

From Stolper et al. (2016) A Pleistocene ice core record of atmospheric O2 concentrations:[0]

> We present a record of Po2 reconstructed using O2/N2 ratios from ancient air trapped in ice. This record indicates that Po2 declined by 7 per mil (0.7%) over the past 800,000 years, requiring that O2 sinks were ~2% larger than sources.

That's 7000 ppm decrease over 800000 years, or 0.009 ppm per year. And so yes, atmospheric oxygen concentration is dropping lots faster now. But TFA's point that it's slow, and regulated by long-term processes, is still valid.

0) https://science.sciencemag.org/content/353/6306/1427

strainer said 25 days ago:

So that's where he is getting the context for his rant >>

"So, in all practical terms, the net contribution of the Amazon ECOSYSTEM (not just the plants alone) to the world's oxygen is effectively zero."

Practically, the reason why we have oxygen in the atmosphere is plant photosynthesis over long terms. We can quibble over the net annual product of every forest and ecosystem as he has - but over geological timeframes, the plant life they contain is the reason we have any oxygen to breath. And if the amazon currently amounts to about 20% of the plant life on earth now, its not wrong to teach that it is doing 20% of the oxygen maintaining.

The fact that long term maintenance is obscured by shorter term dynamics including our modern industrial activity, does not make a lie of the understanding and respect that forests are lungs of the planet.

eveningcoffee said 25 days ago:

I am lately thinking that we are assigning too less value to this fact. We all need oxygen and we should have enough forests to produce it and this means that we should globally subsidize forest keeping. It is not a single country problem. It is a global problem.

nearbuy said 25 days ago:

1. The article explained this isn't true. Carbon dioxide is a problem. Oxygen depletion is not. Burning enough forests to decrease atmospheric oxygen by just 1% would increase CO2 by 5000%. We'd be dead long before we ran out of oxygen.

2. I'm not sure what you have in mind for "short term" vs "long term", but oxygen levels only change significantly over hundreds of millions of years.

3. Just like a stable sized forest doesn't produce any significant net oxygen, humans don't overall use up oxygen from breathing. The plants you eat (or if you're eating meat, the plants your food ate) released oxygen into the air when forming the carbohydrates and fats you eat. Your body then recombines these with an equal amount of oxygen to produce energy.

eveningcoffee said 25 days ago:

Of course excess CO2 is greater problem than lack of oxygen but these things are in 1 to 1 correlation - you need oxygen to burn carbon. The more you burn carbon the more oxygen you join from the environment. To get the same oxygen back you need to breakup all the carbon you burnt.

If you destroy the forest then you will reduce the capacity to remove the CO2 from the atmosphere and produce oxygen or do you disagree with this?

nearbuy said 24 days ago:

Then why mention oxygen? It's irrelevant. It's like advocating that people should only shoot people with non-lead bullets so the victims don't get lead poisoning.

> If you destroy the forest then you will reduce the capacity to remove the CO2 from the atmosphere and produce oxygen or do you disagree with this?

The linked article explains this isn't true. The rainforest is in equilibrium. It doesn't remove CO2 overall. It's a carbon stockpile.

If you were to burn the forest, it would release the stockpiled carbon into the atmosphere as CO2.

shkkmo said 25 days ago:

> over geological timeframes, the plant life they contain is the reason we have any oxygen to breath

About 1/2 of the oxygen produced is produced by Phytoplankton, which are not plants (though they are similar).

> And if the amazon currently amounts to about 20% of the plant life on earth now

The amazon accounts 16% of the photosynthesis on land.

> its not wrong to teach that it is doing 20% of the oxygen maintaining.

It is wrong. If you want to provide a nice round, reasonably accurate number you should use 10%.

> does not make a lie of the understanding and respect that forests are lungs of the planet.

Forests are important and and a significant part of the respiration of them planet, but they are less important than our oceans. Our oceans are the true lungs of the planet (edit: and they are not in great shape, atmospheric oxygen may not be an issue, but oxygenation of the ocean is more variable).

mirimir said 25 days ago:

Sure. But long term, the Sahara may green, and "replace" the Amazon. At this point, I'd worry more about the oceans.

strainer said 25 days ago:

Burning the amazon down is something to worry about. Not afforesting widely and extracting timber from the amazon ecologically so it sequesters carbon and supplies materials replacing demand for carbon intense alternatives - is tragedy.

The advice that amazons contribution is "zero", hedged under this safety-net word "effectively" is false to the understanding of geophysics and natural history. I hope the professor will clarify his language after consideration.

mirimir said 25 days ago:

I'm not arguing that it's not something to worry about. It certainly is something to be worrying about. But so are the tropical forests of Southeast Asia, which are arguably even more threatened.

But we should be worried about it because of the impact on global biodiversity. Not because we'll be running out of oxygen. Having ~20% oxygen in the atmosphere reflects a long-term equilibrium of biologic and non-biologic processes.

If advocates focus on the oxygen issue, adversaries can easily point to negligible changes, and argue that there's nothing to worry about.

And, as I said, to the extent that oxygen is an issue, we ought to worry even more about the oceans. They are by far the major oxygen source, and arguably more vulnerable to catastrophic collapse.

shkkmo said 25 days ago:

> the piece seems to fly in the face of professional work on the subject.

The blogger does professional work on the subject. The article makes it pretty clear that the net positive production of oxygen the the Amazon is so close to zero that it is only relevant on the time scale of millions of years.

james_s_tayler said 25 days ago:

One Strange Rock documentary on Netflix makes the same claim.

smadge said 25 days ago:

I think the charitable interpretation of the use of the “20% of the earths oxygen” statistic (as the article states this is probably more like 9% of earths photosynthesis) is not about an imagined fear of oxygen depletion, but drawing attention to how massive and important an ecosystem the Amazon is.

luckylion said 25 days ago:

That's likely, but we could pretend it's 80% with the same reasoning - and it has an even larger effect with regard to drawing attention to the importance.

smadge said 25 days ago:

I am not excusing the statistic. I think people should be accurate. To me the correct statistic is just as compellingly.

bad_user said a month ago:

Netflix has a pretty cool series called "One Strange Rock". You should watch it, they explain the Amazon's role well in one episode.

First of all oxygen is constant. Oxygen is currently not the problem. And it's a good thing that it's constant because we don't want more of it either.

The problem with Amazon is that on Earth it's all interconnected and while there's plenty of room for failure, there is a tipping point, scientists have only disagreed on where that tipping point is. Once we are there however we will no longer be able to stop the chain reaction.

Retric said a month ago:

There is no single tipping point. There are a vast number of different tipping points with different outcomes.

BurningFrog said 25 days ago:

There is this idea that the ecological balance is very fragile and easily destroyed.

This is true, in a way, but it doesn't mean nature will dies. It almost always just means that nature will find a new ecological balance.

bad_user said 25 days ago:

If nature finds a new ecological balance that's incompatible with human life, does it matter?

BurningFrog said 25 days ago:

This is more a Hollywood movie plot than something that really happens.

zaroth said 25 days ago:

Which is to say, there is no tipping point?

Retric said 25 days ago:

More that many systems are involved, and they are not all binary choices. So, local flooding for example does not operate on the same scale as ocean acidification.

dmix said a month ago:

So you see it being like the singularity that people predicted in tech/AI but for natural disasters?

amelius said a month ago:

> a bigger point that is often missed is that the Amazon consumes about as much oxygen as it produces.

Especially when on fire ...

wodenokoto said 25 days ago:

Consumes as much as it produces ... does that mean the animal life in the amazon consumes all the O2 produces by the plants, or does it mean that the life-cycle of any one tree consumes as much O2 when decomposing, as it produces during its time photosynthesizing?

If it is the latter, then we will see decreased oxygen levels as the forest decreases is size.

badrabbit said a month ago:

"...consumes about as much oxygen as it produces."

If it burns,there will be leftover life that will no longer be supported by the amazon. Causing a significant increase in net Oxygen consumption.

1% uncomoemsated consumption doesn't sound like much but it will remain that way or worse whic means total O2 will continue to deplete.

empath75 said a month ago:

Not for very long.

mrpopo said 25 days ago:

They burn the amazon to leave way for cattle. The abounding biodiversity there will be replaced by cows for mass consumption. His point holds.

MuffinFlavored said 25 days ago:

> Second, a bigger point that is often missed is that the Amazon consumes about as much oxygen as it produces."

Does this mean that if the Amazon rainforest fell off of the map tomorrow, life as we know it would pretty much stay the same/be ok?

ctrl-j said a month ago:

I mean.. I get your point.. but 9% is still a lot, and even if it's net-zero, the carbon sequestration going into that process can't be negligible.

It may be a click-bait factoid, but it's not like that factoid isn't an important one.

Misdicorl said a month ago:

As a follow up to my above, it's the weight of the forest that matters. Older forests typically fit bigger and denser and heavier trees, so the age of a forest still matters a lot. But a fairly established forest like the Amazon is not changing the amount of oxygen out carbon dioxide in the air unless it's expanding or contracting

Misdicorl said a month ago:

There is no active sequestration for a static forest. Only if the forest is expanding in size will sequestration occur. Obviously reducing the size via burning has the opposite effect

cm2187 said a month ago:

But doesn't it regrow from the hashes?

marvin said a month ago:

From the ashes? Not if it's turned into a ranch!

And I'm not qualified to answer what happens when you burn down an entire millenia-old ecosystem. Seems plausible that it might not go straight back to its old self in a human-relevant timeframe.

didbsivdf said a month ago:

“Not if it's turned into a ranch!”

That’s not obvious to me. Most plants are C2 plants, but grass is a C4 so it captures sunlight more efficiently.

Not to say burning the Amazon isn’t a terrible idea.

Armisael16 said a month ago:

Plants pretty consistently are ~40-50% carbon by mass, so the amount of biomass on the ground is a fairly solid indicator of the amount of carbon sequestered. Unless the ranchers have a truly massive amount of hay at all times I don't see how a ranch can approach a forest.

hanche said 25 days ago:

Don’t forget the soil. Old prairie has immensely thick soil, with a high carbon content. Think deep plant roots. With the right management, ranchers could mimic the prairie ecosystem, restore and build soil, and sequester carbon into the soil. It’s not easy, but the most successful farmers have been astoundingly successful.

Not that any of this is a valid excuse for burning down the Amazon.

cm2187 said a month ago:

Well my question is rather if it becomes a growing forest again, ie capturing co2.

Misdicorl said a month ago:

Eventually. See my other comment

said a month ago:
[deleted]
ngold said a month ago:

So yes or no does the amazon provide 20% or not?

shkkmo said 25 days ago:

TLDR: The amazon produces 9% and consumes 9%. We have ~500x more oxygen than CO2 so any disparities will be seen in global CO2 levels WAY before global O2 levels.

molteanu said a month ago:

This is just another political play to oust Bolsonaro, the Brazil's president, from power. There have already been EU voices pushing for sanctions against Brazil and the Amazon fires are on the G7 agenda which brings a lot of negative press against the political body in Brazil. All the while central Africa is also ravaged by fires but you don't hear that in the news.

Like most of what you hear in the big press, it comes with an agenda. It's not the case that a 'zero' was mispelled or enough info was not available, thus the erroneous reporting. You won't win the argument that way. The piece simply has another purpose from the one it is claiming to have, in this case, that future generations will say that the fires wiped out the entire human civilization in all it's glory at the hand of the Brazilian president. Ergo, he has to go until it's not too late.

said a month ago:
[deleted]
meerita said a month ago:

You're being downvoted and I also know why because it's 100% political. It's amazing that HN people downvote this and don't attach to the current evidence (the NASA report) which is 100% clear the fires aren't a new thing and there's no killing amazonia conspiracy from Bolsonaro.

dev_dull said a month ago:

You’re being downvoted, but it clearly is a political move. The fires aren’t even outside of the average and already countries are applying political pressure on the president.

When the facts are detached from the narrative, it’s usually a political story.

skosch said a month ago:

False. The 2019 fires are way outside of the average: http://www.globalfiredata.org/forecast.html

Also, what you call average is only the average over the past few years, which means: illegal loggers and ranchers burning the forest on purpose.

The true long-term average is a healthy forest with very few fires.

icebraining said a month ago:

Can you point out where that page supports that claim?

> only the average over the past few years

That only reinforces in the point; if the numbers changed from the average a few years ago, why the sudden massive response just now?

mrpopo said 25 days ago:

The fires were man-made back then too and there was uproar about it, and the situation improved a lot. But even then deforestation was still ongoing. So it's a step back, meanwhile the deforestation rate never reached 0.

Bjartr said a month ago:

I heard the fires were up by 87% from last year, no matter the base rate, nearly double seems to qualify as "outside the average"

alacombe said a month ago:
skosch said a month ago:

That article is from over a week ago, and it cites http://www.globalfiredata.org/forecast.html#amazon, which has since been updated.

Indeed, people are burning more this year than they did in the past few years – any burning at all has always been unacceptable, but if the current spike is what it takes to finally create some international outrage and put pressure on Bolsonaro, then I'll gladly take it.

gus_massa said a month ago:

> any burning at all has always been unacceptable

It's a traditional farming practice that has been used all over the word https://en.wikipedia.org/wiki/Slash-and-burn

The idea is that you can burn a small place, cultivate it for a few years and then abandon it so the natural grow of the forest regenerate it. And some years later repeat the cicle.

When the population is small it's fine because the time between burn and burn was enough for the soil and forest to recover. When the population increase the time gets too small and the forest has not enough tome to recover, and after a few cicles you have problems like reduction of fertility, erosion and desertification.

tcgv said a month ago:

This subject has been treated so irresponsibly these past few days that not only people are making inaccurate statements such as "the Amazon provides 20% of our oxygen", but also high profile people such as Emmanuel Macron (France's President) and Cristiano Ronaldo (World famous soccer player) are sharing false information and photos[1]

[1] http://translate.google.com/translate?hl=&sl=pt&tl=en&u=http...

m0zg said a month ago:

All of US presidential candidates, democratic and republican alike, routinely and knowingly push blatant lies as a part of their platform and nobody blinks an eye. If you went through what they say with a fine toothed comb and removed all the lies, there'd be hardly anything left. People don't care about facts. They care about how a narrative makes them feel. Sad but true.

ignoramous said a month ago:

Agree. There's purposefully lying to achieve targets, and ignorantly spreading lies that help someone in addition to lending them credibility and exposure. The latter hurts more than the former: For instance, Cristiano Ronaldo is a much bigger influencer than most Senators or even Hollywood personalities can ever hope to be. I think, people like them need to exercise great caution, if they intend to mean well and not cause harm.

Dumblydorr said 25 days ago:

While it's true most politicians lie or bend facts or report them wrongly, you can not create a false equivalence between them all. Trump lies egregiously and far more than basically any non dictatorial politician. Your stance reminds me of those who said both 2016 candidates were bad, so they didn't vote or voted for the two clown third party candidates.

m0zg said 25 days ago:

The entirety of Hillary Clinton's campaign could be summarized as "it's my turn, orange man bad". I can't vote for that. In 2019 I likewise can't vote for open borders, "free money" for everyone, multi-trillion dollar ill-conceived "green deals", or "reparations", because I'd be the one paying for all this shit. Plus, _all_ democratic presidential candidates made the Charlottesville hoax the centerpiece of their campaign, so they too lie 100% knowingly about it.

antpls said 25 days ago:

Regarding the pictures, many pictures of burning forests were shared on social networks those past few days (eg. Instagram stories).

Those are images of fires to illustrate people's message, they convey the greater concept that we should be aware of the Earth as a global shared system. No one is saying 'look at this picture of the Amazon burning right now' (not even in the Macron's tweet).

Regarding "the Amazon provides 20% of our oxygen", I guess it could be debated, and the biodiversity would probably have been a better argument.

shkkmo said 25 days ago:

> Regarding "the Amazon provides 20% of our oxygen", I guess it could be debated,

I think it is flat out wrong and not really debatable. Also, focusing on oxygen is not the right thing to talk about because we have so much more oxygen than carbon dioxide.

Before we manage to consume significant amounts of our oxygen, we will have released so much carbon dioxide that a slight dip in O2 will not be a concern.

dev_dull said a month ago:

It’s almost like these people are more interested in pushing a narrative and not the facts?

jgeerts said 25 days ago:

In present days it's really hard to get factual, correct, unbiased news.

seppin said a month ago:

It's almost as if these specific details are wrong but the greater trend is happening, so why fixate on it?

dredmorbius said 25 days ago:

What impressed me most from this article was the gross primary productivity map (http://www.yadvindermalhi.org/uploads/1/8/7/6/18767612/scree...), showing plant activity by region.

The red regions are largely tropical rainforest. Exceedingly highly productive, but not particularly viable for human agricultural activity.

What stands out are the regions which I'm aware are highly agriculturally productive, indicated in green and cyan: the eastern half of the US, generally, the Argentine and Brazillian Pampas regions, the Sahel, Europe (particularly western Europe -- England, France, and Germany), and south and East Asia. A small patch of Central America.

Notably contrasting: the western US, other than a thin strip (the central valleys of California and Oregon), the Australia, other than the extreme south-eastern band, the Sahara, virtually all of Russia, western South America, and most of Canada. And of course, the Sahara and Antarctica.

We're feeding 7.7 billions of souls on those regions of green and light blue. Those are also the regions in which the great civilisations of the past have developed -- compare with a time-lapse of human population such as:

https://invidio.us/watch?v=PUwmA3Q0_OE

zests said a month ago:

What do you do when people quote statistics like this in real life? I usually just sit there like an insincere fool and remain quiet or offer lukewarm agreement. I can't bring myself to tell them that I disagree because I don't want to be rude but at the same time my current system is not working.

luckylion said 25 days ago:

I found that, for me at least, it kinda works to not outright disagree, but to say that you 'read an article' that disputed said fact and now you're confused about whether it's actually true. I usually see one of three things happening: they say something along the lines of "oh, I don't know a lot about that, so I can't tell you" and the conversation moves on, they tell you "it's obviously bullshit, because I read it in $magazine", or they'll engage with it to try and lift your confusion. In the latter case, you can feed them arguments and facts, but since it's not a debate ("you're wrong" - "no, YOU are wrong"), it's easier for them to see when/where their beliefs fall short.

pas said 25 days ago:

Simply share the fact you know, be prepared to explain how you know that it's reliable, what are the implications of the difference.

In my experience people listen to people who can explain things, not just claim that something is wrong/false.

BurningFrog said a month ago:

What you need to know: This has zero impact on oxygen levels. It might be a real problem for CO₂.

Anyway, the geological history of oxygen is pretty wild:

https://en.wikipedia.org/wiki/Geological_history_of_oxygen

bendbro said a month ago:

This whole "RAINFOREST IS ON FIRE" meme reminds me a lot of Kony 2012.

thepangolino said a month ago:

Exactly. It’s highlights a real issue but completely misplaces mobilisation.

RandomBacon said a month ago:

But then you get the people that say, "At least they're doing something."

jdnenej said a month ago:

Well wtf can anyone really do about a disaster on the other side of the world.

pas said 25 days ago:

Probably incorporate their concerns when they vote. Choose representatives, leaders, groups you support (parties), that share your concern, that try to have an efficient foreign policy that cares about these things.

Naturally, this includes some marketing to support the message and to try to persuade as many people as you can.

DenisM said a month ago:

A few comments are saying that forests capture a lot of CO2.

But how could that be? If a forest doesn't change over thousands of years it cannot be accumulating carbon in any significant quantity. Or else where would that material go?

The Amazon trees are about as tall and wide today as they were 10,000 years ago, and only so many of them fit on a given area. If the amount of vegetation remains the same the only way for a forest to capture carbon would be to accumulate an ever-increasing layer of it under the forest floor. That would be a lot of combustible material accumulated over millions of years that Amazon was around, and I'm pretty sure it isn't there (otherwise certain people would be mining it already).

Amazon is not scrubbing carbon out of the air, and neither does any other forest of static size. The carbon has to go into the ground to remain sequestered.

patmcc said 25 days ago:

>>>A few comments are saying that forests capture a lot of CO2.

As you indicate, those people are incorrect. But a forest may contain a lot of C02, such that burning it all at once increases the amount in the atmosphere noticeably.

cmrdporcupine said 25 days ago:

Temperate forests sequester carbon over millions of years by leaving a layer of carbon rich top soil beneath them through leaf and other litter fall.

Soil can hold a _lot_ of carbon per square foot. Carbon that is partially lost to the atmosphere when it is plowed.

But my understanding is that tropical forests tend to have fairly carbon poor soils on the forest floor.

DenisM said 25 days ago:

The only way it could work is for the top soil to grow thicker by the year, reaching huge depths over tens of millions of years. As I recall my temperate forests, the topsoil is skin-deep, relatively speaking.

cmrdporcupine said 25 days ago:

If you take a core sample from an established forest it's often got at least 5-6 feet of heavy dark carbon rich soil beneath. That's the case on my property anyways. I had some trees moved with a giant tree spade some years back. Sandy soil, but the top 5 feet was nice and dark. The area would have been forest and marsh only about 50-100 years ago.

DenisM said 24 days ago:

Amazon has been around for 55 million years. Do you think we will find the topsoil to be 55,000,000 / 100 * 5 feet thick? I wager it went up to like 20 feet max in the first million years and hasn’t changed since then.

Rebelgecko said 25 days ago:

Doesn't burning the forest down release a good portion of that CO2?

DenisM said 25 days ago:

My point is that a standing forest doesn’t affect carbon levels. A growing forest or a burning forest does.

So a statement like “forests are scrubbing CO2 and help us against climate change” are false - a stationary size forest has no effect whatsoever.

For carbon to be sequestered it has to go into the ground and stay there.

crimsonalucard said 25 days ago:

https://wwf.panda.org/knowledge_hub/where_we_work/amazon/ama...

it's just less accessible but I'm pretty sure like any forest on the face of the earth, portions of dead animal and plant matter is getting sequestered into the ground while another portion is getting exhaled by animals eating the leaves or other animals eating the animals.

The stuff that's getting sequestered though is probably miniscule. At the timescale of our lifetime it may be negligible but I wouldn't know as I'm not an expert. Perhaps someone with the actual data can fill us in?

shkkmo said 25 days ago:

Well, just based on the linked article:

> A final point to make is that the atmosphere is awash with oxygen, at 20.95% or 209,500 ppm (parts per million). Carbon dioxide, by comparison, is around 405 ppm and rising by around 2-3 ppm per year, over 500 times less. Human activity (around 90% of which being fossil fuel combustion) has caused this concentration to drop by around 0.005% since 1990, a trivial amount. In parallel, the same activities have caused carbon dioxide concentrations to rise by by 37 ppm since 1990, or 10%. This is a much more substantial percentage because there is so little carbon dioxide in the atmosphere to begin with, so human activities can make a major difference. This is why we need to worry about the increase of carbon dioxide in the atmosphere (and its resulting impact on climate), and why we don't need to worry about running out of oxygen.

The 3 order of magnitude difference is the relevant bit of info.

So while it takes millions of years for the amazon to have an impact on )2 levels, impacts on CO2 levels happen on the time scale of thousands of years.

This is also why it makes more sense to be concerned about the CO2 being released by burning the Amazon than the oxygen consumed by the fire.

DenisM said 25 days ago:

Even if a tiny amount was sequestered each year over the course of 55 million years there would be a huge pile of carbon there. But it isn’t there, is it?

OscarCunningham said 25 days ago:

Has the soil under the rainforest been slowly getting deeper?

abdullahkhalids said 25 days ago:

There is. That's all the coal, oil and gas we burn.

crimsonalucard said 25 days ago:

my initial reply was a post about oil mining in the amazon...

Additionally tectonic plates move, 55 million years ago the amazon probably wasn't even there. Additionally oil found on land could've been produced by biomass under the ocean and vice versa it's all moving around all the time. Likely the oil found underneath the amazon could have been produced at a time where that tectonic plate was under water.

justanothernoob said a month ago:

You aren't accounting for the trees being living, growing beings. Asking how they capture CO2 is kind of like asking how we grab oxygen- it's in the air, we use it to fuel our growth and stay alive, and then it's CO2 when it leaves our bodies. It's the reverse for trees, I don't know if any significant amount of solid carbon would need to accumulate, as it forms the wood and the varies trees that grow and die.

crimsonalucard said 25 days ago:

A forest of constant size is not growing and therefore not removing any carbon from the air is this persons argument.

povertyworld said a month ago:

I haven't been following this specific news story, but I remember from my environmental sociology class that fire prevention in forests eventually leads to unnatural states that are then prone to massive uncontainable fires. Have they been suppressing natural fire in this region for too long? If this fire is naturally burning, then isn't the best response to let it run its course unless human lives are threatened?

pvaldes said a month ago:

> Have they been suppressing natural fire in this region for too long?

This is confusing for many people, I know.

Ecosystems tend to increase its complexity with time. From lava field to savanna to forests. This is how it works. Life fills the gaps.

If untouched, forests aim for the higher state of organisation possible, the so called "climax": A big forest, with huge old trees. Plants accumulate water, big plants accumulate big water, plants make water also (Is a by-product of this respiration)...

...therefore the climax is a humid forest of some kind (a rainforest, a bamboo cloudforest, a laurisilva, a scottish caledonian rainforest, a sequoia forest)

A place full of spongy fungus and plants accumulating water, a place that creates its own climate and make rains that collect in streams and then in rivers for the people benefit. They do not need fire to work at all. Wildfires are scarce and self-contained events. Such places would need a lot of energy to start burning.

The young forest is vulnerable to fire. For decades the fire risk increases. This is that people remember, but sadly they do not see the second part. After a thousand years, the risk start decreasing and then the entire area is fire-proof. Wildfires stop often when reaching an old forest.

The tragedy is that before to reach this state of full healing, the forest is burned again BY MAN (>90% of wildfires are caused by man). Is called "necessary management" or "reducing the risk", but life does not need human management. Has evolved to sustain maximum amount of life possible. We need "Management" is another way to say we want "nature explotation". Is the "groundhog day" film with trees.

Nobody is trying to restore it and return the water to Mediterranean or to California because... it would need two or three human generations to show results and it would need much smarter humans.

sambal said 25 days ago:

I’d love to read more on this humid forest climax narrative from any credible sources, it sounds interesting and I don’t know anything about this sort of thing really, but at the same time it’s tripping my “just-so” sensors something heavy!

pvaldes said 25 days ago:

I bet that you will find plenty of credible sources if you study biology and learn some basic ecology (ecology as science, not as ideology). None of what I'm saying is a secret and is also easily verifiable empirically.

There are also parts of this science that deal with the study of stress in ecosystems. A low or medium source of stress can increase the biodiversity. A mix of healed and degraded ecosystems can provide habitats for different types of life beings. A big source of stress otherwise will distroy all the job done by time and simplify the ecosystem. Moreover, the damage can be so deep that the new state of organisation enters in a loop. The remain is just too flammable to advance and the only species surviving benefit from fire so they need fire to keep competitors at bay, germinate and survive. And they make fire creating flammable structures. Fire triggers water quiting the area and will distroy soil organic structure. Without water the future of the area enters in a reverse path, to savanna, then arid, finally desert. Is happening in California for example.

For climate change figthing purposes, the closer to the ecological climax, the better chance for long-term human survivorship.

Climate change will actively distroy climactic ecosystems also (more hurricans, etc), so the problem is more complicated that "just stop chopping trees and damaging coral reefs with tourist cruises". We can expect a lot of problems and extinction cascades in the future.

FiatLuxDave said 24 days ago:

A good book that talks about this effect, along with lots of interesting connections between thermodynamics and ecology, is "Into the cool" by Sagan and Schneider

gleglegle said 25 days ago:

The Amazon does not burn naturally. Fires there are man made to clear land for agriculture.

dna_polymerase said 25 days ago:

Yes it does. Especially in the dry season, although those fires usually are less severe than those caused by humans.

Misdicorl said a month ago:

This is not true for rainforests afaik. There is no fire cycle like for the mountain forests of the US West

chrisco255 said a month ago:

This is not true of the rainforests themselves, but the Amazon region is not 100% rainforest. It also has savannas and drier forests in parts of it (it's a massive region).

sp332 said a month ago:

These are fires for agricultural land. They're much smaller than natural forest fires but many of them are set at once at the beginning of the season, so it's still a lot of forest on fire.

diedyesterday said 24 days ago:

A subtle point that is often missed is that only a growing plant population and ecosystem will have a positive oxygen balance and negative CO2 balance (trapping CO2 as tree biomass at ever increasing volume). Stable ecosystems reach an equilibrium and the carbon cycle stabilizes and net oxygen/CO2 production consumption becomes zero.

To increase net oxygen levels in the atmosphere and reduce CO2 levels we would also have to eliminate a lot of the microorganisms that help recycle dead trees and go back to the Paleozoic era and before when these organisms didn't exist and the Earth witnessed several glaciation events.

Adding more stable forests to the world does not reduce CO2 levels or increase oxygen levels (relative to after it becomes a stable forest). It just speeds up the carbon cycle.

EGreg said 25 days ago:

I have a question about trees:

If trees sequester carbon in their trunks and release oxygen, what do they use the oxygen for at night, and how come they are oxygen-neutral, do they store it somehow?

Also, if the Amazon is a carbon sink today, what about if there was dieback? It would turn into a carbon source, but how? Don’t the “unit economics” of trees remain the same?

gus_massa said 25 days ago:

Oversimplifiying: Some of the carbon goes to the wood and some goes to sugar. During the night the plant "burns" the sugar with oxygen produce energy. (If you keep a plant in hermetic place without oxygen and without light, it would die, exactly like an animal.)

(Notes about the oversimpliplification: Wood is made of cellulose that is a carbohydrate and sugar is algo a carbohydrate, they are quite similar chemically. Also, plants produce and "burn" other compounds.)

amriksohata said 25 days ago:

What this article doesn't go into is if the forest is destroyed, what the net effect is, it consumes as much oxygen as it produces, but once those animals have no oxygen they will put a strain on the surronding ecosystem. Not to mention the flash floods that will result from the lack of vegetation

said a month ago:
[deleted]
gdubs said 25 days ago:

This thread feels politically toxic. The discussions seems to be heavily focused on a “gotcha”, exploiting a kind of Guilt By Association fallacy to minimize the disturbing event unfolding in the Amazon.

“The lungs of the world” is a poetic phrase. Trying to make it literal diminishes it, by giving cynics a small thread to pull on until it unravels — while in the process ignoring all the other ways in which the Amazon is important.

A vibrant discussion of the original post would be relevant — using the misaccounting as a cudgel against environmentalists and journalism as a whole is explicitly not the spirit of HN.

said a month ago:
[deleted]
palisade said a month ago:

More importantly as the planet's "lungs" the Amazon filters a great quantity of carbon dioxide from the air.

gus_massa said a month ago:

No, with some minor simplifications, the plants amount of CO2 that the pants absorb is proportional to the amount of O2 they produce. So

Does the Amazon provide 20% of our oxygen?

is equivalent to

Does the Amazon remove 20% of our waste carbon dioxide?

The main part of the "lungs" of the planet is the phytoplankton in the sea.

m0zg said a month ago:

I googled some and it looks like Amazon rainforest alone removes about a quarter of fossil fuel CO2 from the atmosphere. That's more than I thought it'd be. And it looks like it could sequester much more if there was more phosphorus in the soil.

jamesdmiller said a month ago:

Where do they put it? Wouldn't this require the total biomass of the rainforest to be continually increasing?

sp332 said a month ago:

Old growth forests are not carbon-neutral. Models had to be adjusted after this study in 2008: https://www.csmonitor.com/Environment/Global-Warming/2008/09...

sp332 said a month ago:

Where did you see that figure?

m0zg said a month ago:

https://newscenter.lbl.gov/2019/08/20/amazon-rainforest-abso...

Quote: "The Amazon Basin is critical to help mitigate climate change due to its trees absorbing around a quarter of the CO2 released each year from the burning of fossil fuels."

shkkmo said 25 days ago:

This is why you need to be careful about understanding and quoting scientific facts.

The specific quote is talking about trees in the rainforest, not the rainforest itself. The rainforest is an ecological system that also produces CO2 (mainly through microbes breaking down wood) and you can't ignore the rest of the system.

Which is not to say that the Amazon doesn't play a significant in the global environment and weather systems.

crb002 said a month ago:

Guessing a lot is ocean based, and plants are more efficient at getting it with higher concentrations.

squirrelicus said 25 days ago:

tl;dr the rule holds, the answer is no. :]

Though i have to admit to bring skeptical of his analysis that suggests the rainforest is a net zero on oxygen production.

d0100 said 25 days ago:

Even if it did, all these EU colonialists using the Amazon as a red herring because things aren't going well back home should first stop destroying the other 80% with their industrialization and irresponsible consumerism.

Macron: "We the G7, the most industrialized and polluting nations, should gang up on this up and coming 3rd world country. Look at my might!!"

Go wave a white flag Macron

m3kw9 said 25 days ago:

Amazon sells oxygen canisters?

diego_moita said a month ago:

No, it doesn't provide.

But the article totally misses the issue of carbon capture.

higherkinded said a month ago:

Wrong Amazon, you again!

_emacsomancer_ said 25 days ago:

Eventually Amazon may provide 20% of our oxygen....

said 25 days ago:
[deleted]
dvduval said 25 days ago:

So far there have not been too many third-party merchants who have profited on selling oxygen, but once they do, Amazon will definitely move in and take on this part of the market as well.

paggle said a month ago:

20% of sequestered carbon dioxide is in the Amazon. If it burns to the ground then that CO2 will be released. It doesn’t affect oxygen levels.

ridgeguy said 25 days ago:

Isn't it 20% of sequestered carbon, not CO2?

Burning that carbon to CO2 requires oxygen, which will deplete the atmospheric reservoir to some degree.

paggle said 25 days ago:

But isn’t there oxygen in the organic materials of the tree?

ridgeguy said 25 days ago:

I think the oxygen in the tree materials is already combined with carbon in the form of CxHyOz hydrocarbons, where x,y,z = atoms of the respective atomic species.

Burning cellulose (poly-C6 H10 O5) to CO2 and H2O would require (for each molecule): 12O (for 6CO2) and 5O (for 5H2O). This is a total of 17O.

Cellulose contains only 5O, so 12O (or 6O2) would be required for a full stoichiometric burn of cellulose.

sabujp said a month ago:

You know what, it really doesn't matter because the majority of people don't really care about and understand all of the other effects. People don't even understand global warming or care enough to do anything about it. Talking heads, pundits, and politicians should just inflate the numbers and say that it provides 50% of oxygen and that we'll all asphyxiate without it because the truth is that people won't care unless you make them scared enough to care. If the end goal is to save as much of the forest as possible then stretching the truth doesn't matter. How many lies have been told from the other side for decades to reduce environmental regulations?