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Does the Amazon provide 20% of our oxygen?

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Re: Does the Amazon provide 20% of our oxygen?

#121

Post by patmcc »

DenisM wrote: post #71

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…

>>>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.

Re: Does the Amazon provide 20% of our oxygen?

#122

Post by luckylion »

zests wrote: post #43

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.

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.

Re: Does the Amazon provide 20% of our oxygen?

#123

Post by BurningFrog »

strainer wrote: post #114
wcunning wrote: post #3

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 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…

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

Re: Does the Amazon provide 20% of our oxygen?

#124

Post by james_s_tayler »

strainer wrote: post #114
wcunning wrote: post #3

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 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…

One Strange Rock documentary on Netflix makes the same claim.

Re: Does the Amazon provide 20% of our oxygen?

#125

Post by aetherson »

untog wrote: post #116
rayiner wrote: post #111

Earlier quoted context omitted.

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 busine…

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.

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

Re: Does the Amazon provide 20% of our oxygen?

#126

Post by BurningFrog »

Retric wrote: post #31
bad_user wrote: post #28

Earlier quoted context omitted.

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…

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

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.

Re: Does the Amazon provide 20% of our oxygen?

#127

Post by EB66 »

BurningFrog wrote: post #123
strainer wrote: post #114

Earlier quoted context omitted.

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…

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 prod…

> 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.

Re: Does the Amazon provide 20% of our oxygen?

#128

Post by nearbuy »

EB66 wrote: post #127
BurningFrog wrote: post #123

Earlier quoted context omitted.

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 prod…

> 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 th…

Then where is the carbon going?

Re: Does the Amazon provide 20% of our oxygen?

#129

Post by [deleted] »

EB66 wrote: post #127
BurningFrog wrote: post #123

Earlier quoted context omitted.

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 prod…

> 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 th…

[deleted]

Re: Does the Amazon provide 20% of our oxygen?

#130

Post by EB66 »

nearbuy wrote: post #128
EB66 wrote: post #127

Earlier quoted context omitted.

> 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 th…

Then where is the carbon going?

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.

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