I have a serious concern that good answers are being ruled out by moderators as theoretical even though they are based on a basic understanding of simple physical processes.
My concern is based on how some answers to this question (and some similar previous questions) have been handled. (a separate issue is that the question itself is currently marked as a duplicate despite being about a far more specific claim than the original question and despite looking for and generating answers that the answers to the previous question simply don't address).
The question asked whether this claim was remotely plausible (given a model that said that oxygen production in the ocean could be drastically reduced):
By 2100, the earth at sea level could have atmospheric oxygen levels comparable to the top of Mount Everest today. And as far as I know, people cannot normally stay on Everest without oxygen masks for more than a few minutes.
I understand this claim as having three components:
- a model says oxygen production could be drastically reduced (this is (badly) addresses in a previous question leading to the claim that the new question is a duplicate)
- assuming point 1 is true, drastic effects could be seen by 2100 on atmospheric oxygen levels
- specifically, the oxygen at sea-level could be as low as it currently is at the top of Everest
The moderator response to the question justifying marking it as a duplicate claimed this:
I don't really understand the difference between this question and the dupe: I understand the other does not ask specifically about the 70% number, but neither does this.
It is worth noting that the previous question didn't address either the timescale or the scale of the problem but the claim in this question specifically mentioned both. The 70% is a round number of the reduction required in oxygen levels to reach the levels on Everest (which I originally assumed was so obvious it didn't need a reference).
I assumed that by providing the direct quote about the specific claim it would be clear why this was different from the original question. The moderator didn't appear to grasp this. I clarified the point but the moderator has not yet reversed this judgement. Perhaps a lack of physical intuition by the moderator inhibits what I assumed would be very obvious. This is relevant for the next part.
The problem with the answers
To me, there is a simple and direct way to address the claim which uses only easily referenceable (googleable or available on Wikipedia) facts. And two answers (not by me) initially took this approach (though I did answer a related but now deleted question using a very similar approach).
Quoting from a now erased answer:
The movement of oxygen to and from the atmosphere is called the oxygen cycle. All of the numbers used below are from this Wikipedia article, and all calculations are provided in WolframAlpha.
Using Wikipedia's numbers, the atmosphere:
Stores ~1.4*1018 kg of oxygen.
Gains ~3*1014 kg of oxygen per year.
About half of which is from the ocean.
Loses ~3*1014 kg of oxygen per year.
To me the references to our knowledge about the atmosphere establish that the stock of oxygen in it is about 5,000 times larger than the annual production and consumption rates. There is nothing theoretical about this.
We could also calculate the initial rate of reduction in oxygen levels if there were no more production. At most a complete cessation of oxygen production would lead to a reduction in concentration of 83/5000ths of the current level (based on 83 years to 2100 and using 1/5000 of the stock every year). This calculation seems to me both unproblematic and based on referenceable calculations done by atmospheric scientists (residence time of gases in the atmosphere are calculated this way, see this). But this calculation has been judged to be "theoretical" when used in an answer.
But the simple fact that the oxygen stock is vastly larger than the annual production should establish the implausibility of a claim that stopping production would reduce the concentration by 70% regardless of how we model consumption unless the claim is that a vast new sink for oxygen also occurs (but this isn't the claim).
One objection to this simple approach is that the atmosphere isn't well mixed. Again, poor intuition might lead you to assume this, but a simple google search or looking at the Wikipedia source for the facts about the atmosphere would tell you this isn't the case. If this needs to be justified, then asking for a reference is a better response than damning the answer as theoretical (simple school teaching aids show that the troposphere is well mixed).
So, it seems to me, that using some basic knowledge of atmospheric science (all of it derived directly from reliable sources) we can show that a claim that the atmosphere will lose 70% of its oxygen if we stop producing more oxygen is ridiculously implausible (unless some additional claim is made that enormous new drains of oxygen also happen which is not in this claim).
This is basic physical intuition based on directly referenced facts. It isn't theoretical (and requires no complicated model to be justified). It isn't, therefore theoretical to use these facts to answer the question.
My core concern here is that there are are many questions where simple answers of this sort are a very good way of addressing implausible claims. If we rule out this sort of answer, we are preventing good answers from emerging. The literature may regard many of these as too trivial to address in published work (because of the obvious nature of the answer) thereby leaving ridiculous contentious claims unaddressed.
A counter argument might be that bad math in simple arguments has to be justified or bad answers will slip past the net on this site. But using the "theoretical" argument is a sledgehammer to crack a nut for this type of question. Bad logical steps in these arguments are very easy to spot and address with existing rules. In this case, it seems to me, that an answer where both every fact and every calculation can be justified is still ruled out as theoretical because of the rules designed to cope with something else.
So why are moderators leaping to rule out this sort of answer as "theoretical"?