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Does the Amazon provide 20% of our oxygen?

yadvindermalhi.org

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

#151

Post by nearbuy »

EB66 wrote: post #142
nearbuy wrote: post #133

Earlier quoted context omitted.

> 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 phot…

> 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.

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.

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

#152

Post by strainer »

mirimir wrote: post #135
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…

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 re…

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.

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

#153

Post by dangxiaopin »

shkkmo wrote: post #138
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…

> 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…

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.

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

#154

Post by shkkmo »

antpls wrote: post #148
tcgv wrote: post #6

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...

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 provi…

> 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.

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

#155

Post by OscarCunningham »

DenisM wrote: post #100
crimsonalucard wrote: post #92

Earlier quoted context omitted.

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 timesca…

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?

Has the soil under the rainforest been slowly getting deeper?

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

#156

Post by shkkmo »

strainer wrote: post #146
shkkmo wrote: post #138

Earlier quoted context omitted.

> 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…

> 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 st…

> 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.

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

#157

Post by EB66 »

shkkmo wrote: post #138
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…

> 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…

> 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.

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

#158

Post by shkkmo »

EB66 wrote: post #157
shkkmo wrote: post #138

Earlier quoted context omitted.

> 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…

> 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 dow…

> 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.

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

#159

Post by eveningcoffee »

strainer wrote: post #152
mirimir wrote: post #135

Earlier quoted context omitted.

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 re…

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 timeframe…

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.

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

#160

Post by smadge »

luckylion wrote: post #120
smadge wrote: post #118

Earlier quoted context omitted.

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.

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.

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