# Run out of breathable oxygen? **URL:** \ **Category:** Factual Questions\ **Created:** [October 8, 2015, 9:08am UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909 "2015-10-08T09:08:43Z")\ **Posts on this page:** 18\ **Page:** 1
**Author:** ![mandala](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mandala/32/95_2.png) [@mandala](https://boards.straightdope.com/u/mandala)\ **Post date:** [October 8, 2015, 9:08am UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/1 "2015-10-08T09:08:43Z")
Given the current rate of deforestation, how long before we run out of breathable oxygen in the atmosphere? And while we are at it, which type of tree produces the maximum oxygen per day? Need answer fast. If this is going to happen within my lifetime, I gotta start stocking up on oxygen cylinders right away before the teeming millions wake up to the situation and start the mother of all riots. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [October 8, 2015, 9:40am UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/2 "2015-10-08T09:40:44Z")
Like…never. Don’t forget half of the worlds oxygen comes from the Ocean. ---
**Author:** ![DinoR](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dinor/32/2821_2.png) [@DinoR](https://boards.straightdope.com/u/DinoR)\ **Post date:** [October 8, 2015, 10:40am UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/3 "2015-10-08T10:40:19Z")
How’s never. Unless you find the fountain of youth you can stop worrying about that apocalypse. Trees are almost oxygen neutral across their life span. They release oxygen while growing but consume it when they die and decompose. Only the trees that are protected from that decomposition (say making stuff out of wood or falling in to swamps) produce a net positive across their entire life cycle. Even cutting down all the forests and burning them (which would chew up oxygen all at once and not replace it from other trees) would have a negligible affect on us having enough oxygen for life. [Cite](http://www.northcoastjournal.com/humboldt/do-forests-protect-our-oxygen/Content?oid=2126297) [Cite](http://www.columbia.edu/cu/21stC/issue-2.1/broecker.htm) ---
**Author:** ![Asimovian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asimovian/32/172_2.png) [@Asimovian](https://boards.straightdope.com/u/Asimovian)\ **Post date:** [October 8, 2015, 12:14pm UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/4 "2015-10-08T12:14:20Z")
As stated, this seems like a GQ thread. I’ll relocate it. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [October 8, 2015, 12:32pm UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/5 "2015-10-08T12:32:57Z")
It may be worth noting that vegetation takes many forms apart from trees. ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [October 8, 2015, 12:44pm UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/6 "2015-10-08T12:44:54Z")
There was a 1.3% forest loss from 2000 to 2010, down from 2% the previous decade. North America is stable. Europe and Asia are becoming more forested. FAO has more data somewhere on their website, which I can’t get to work this morning. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [October 8, 2015, 1:19pm UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/7 "2015-10-08T13:19:04Z")
> [@Ruken](#): > > There was a 1.3% forest loss from 2000 to 2010, down from 2% the previous decade. North America is stable. Europe and Asia are becoming more forested. FAO has more data somewhere on their website, which I can’t get to work this morning. I had read somewhere that the Northeast US is actually more forested now than it was back in the 1700s because back then it was all covered with farms. I don’t know if that’s true. AFAIK, the main issues around deforestation are in South America. But that has more to do that destruction of rainforest habitats than killing all the oxygen producing trees. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 8, 2015, 1:30pm UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/8 "2015-10-08T13:30:42Z")
Plants do not generate oxygen merely by existing, only by growing. A plant (or a group of plants) that’s maintaining a constant size is consuming exactly as much oxygen as it’s producing. Think of it this way: Photosynthesis turns carbon dioxide into oxygen by, in effect, removing the carbon atom from it. But all of those carbon atoms still have to go somewhere. When an acorn grows into a mighty oak tree, all of that carbon (along with hydrogen from water and some oxygen, plus traces of other elements) is getting turned into wood and other tree parts. But if the oak tree is constant in size, where would it be going? Cutting down a mature tree to turn it into houses or furniture does nothing to the carbon dioxide or oxygen balance: All that carbon was sequestered in the form of wood before, and it’s still sequestered in the form of wood afterwards. Cutting down a tree and burning it does change the balance, because you’re taking carbon that was sequestered and releasing it back into the atmosphere. But even that is only a one-time shift, and that tree being gone will not cause the oxygen level to keep on decreasing after it’s finished burning. And if you plant more trees to replace the ones you cut down, it’s neutral again. ---
**Author:** ![Ornery\_Bob](https://avatars.discourse-cdn.com/v4/letter/o/da6949/32.png) [@Ornery\_Bob](https://boards.straightdope.com/u/Ornery_Bob)\ **Post date:** [October 8, 2015, 1:58pm UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/9 "2015-10-08T13:58:53Z")
Atmospheric oxygen comes from [blue-green algae](http://www.ucmp.berkeley.edu/bacteria/cyanolh.html). ---
**Author:** ![davida03801](https://avatars.discourse-cdn.com/v4/letter/d/b5e925/32.png) [@davida03801](https://boards.straightdope.com/u/davida03801)\ **Post date:** [October 8, 2015, 2:21pm UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/10 "2015-10-08T14:21:12Z")
Simple solution. Know all of that CO2 that everyone is all up in arms about. Note the 2 part of it. Two parts O to one part C Just split all that CO2, problem solved. ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [October 8, 2015, 2:40pm UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/11 "2015-10-08T14:40:46Z")
> [@davida03801](#): > > Simple solution. Know all of that CO2 that everyone is all up in arms about. Note the 2 part of it. Two parts O to one part C > > Just split all that CO2, problem solved. For interested readers: > **[Photoelectrochemical reduction of carbon dioxide](https://en.m.wikipedia.org/wiki/Photoelectrochemical_reduction_of_CO2)** > > Photoelectrochemical reduction of carbon dioxide, also known as photoelectrolysis of carbon dioxide, is a chemical process whereby carbon dioxide is reduced to carbon monoxide or hydrocarbons by the energy of incident light. This process requires catalysts, most of which are semiconducting materials. The feasibility of this chemical reaction was first theorised by Giacomo Luigi Ciamician, an Italian photochemist. Already in 1912 he stated that "\[b\]y using suitable catalyzers, it should be possibl... > **[Electrochemical reduction of carbon dioxide](https://en.m.wikipedia.org/wiki/Electrochemical_reduction_of_carbon_dioxide)** > > The electrochemical reduction of carbon dioxide, also known as CO2RR, is the conversion of carbon dioxide (CO2) to more reduced chemical species using electrical energy. It represents one potential step in the broad scheme of carbon capture and utilization. > CO2RR can produce diverse compounds including formate (HCOO-), carbon monoxide (CO), methane (CH4), ethylene (C2H4), and ethanol (C2H5OH). The main challenges are the relatively high cost of electricity (vs petroleum) and that CO2 is often ... Note that this typically produces water. For producing oxygen: [Artificial photosynthesis - Wikipedia](https://en.m.wikipedia.org/wiki/Artificial_photosynthesis) If oxygen is all you’re after, you can just get that from water oxidation. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [October 8, 2015, 3:13pm UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/12 "2015-10-08T15:13:23Z")
> [@](#): > > Quoth **davida03801** : > > Simple solution. Know all of that CO2 that everyone is all up in arms about. Note the 2 part of it. Two parts O to one part C > > Just split all that CO2, problem solved. I don’t know if this was intended seriously or not, but in case it was: Splitting CO[sub]2[/sub] requires energy, and that energy would have to come somewhere. It’s the same energy, in fact, that you would get from burning that amount of carbon, which is why we’ve produced all that CO[sub]2[/sub] to begin with. If we someday get working fusion or magical unicorn dust or some other source of energy that’s both clean and cheap enough, then maybe we’ll start doing that as a way of repairing the damage we’ve already done, but until that happens, it’s a circular problem: If we had the non-fossil-fuel means to get the energy to split the CO[sub]2[/sub], then we wouldn’t be producing the CO[sub]2[/sub] to begin with. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [October 8, 2015, 3:14pm UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/13 "2015-10-08T15:14:48Z")
> [@msmith537](#): > > I had read somewhere that the Northeast US is actually more forested now than it was back in the 1700s because back then it was all covered with farms. I don’t know if that’s true. NH alone has shifted from a low of 45% forest in the mid-1800s to 85% forested now. Maine has more forested land now (89%) but I don’t think it ever dipped as low as NH. Both states were around 90% forest before European settlers arrived. > **[New Hampshire Forests | Wildlife Journal Junior](http://www.nhptv.org/wild/nhforests.asp)** > > By the 1850s about 70% of the land south of the White Mountains had been cleared of trees. The land in the northern part of the state had been left alone because it was too difficult to transport lumber from the mountains. The railroads changed that!... ---
**Author:** ![Alley\_Dweller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alley_dweller/32/430_2.png) [@Alley\_Dweller](https://boards.straightdope.com/u/Alley_Dweller)\ **Post date:** [October 8, 2015, 3:33pm UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/14 "2015-10-08T15:33:27Z")
> [@Chronos](#): > > I don’t know if this was intended seriously or not, but in case it was: Splitting CO[sub]2[/sub] requires energy, and that energy would have to come somewhere. It’s the same energy, in fact, that you would get from burning that amount of carbon, which is why we’ve produced all that CO[sub]2[/sub] to begin with. If we someday get working fusion or magical unicorn dust or some other source of energy that’s both clean and cheap enough, then maybe we’ll start doing that as a way of repairing the damage we’ve already done, but until that happens, it’s a circular problem: If we had the non-fossil-fuel means to get the energy to split the CO[sub]2[/sub], then we wouldn’t be producing the CO[sub]2[/sub] to begin with. Hmmm… This got me to thinking. When the weather is mild, the wholesale price of electricity on the grid often turns negative in the middle of the night. The electric generators can’t all be turned off, but nobody wants to buy the electricity they are producing. So the generation companies actually have to pay somebody to take the excess electricity off their hands. When the price of electricity is negative, could someone make a profit turning CO2 into O2? Could the generators save money by doing it themselves? ---
**Author:** ![sitchensis](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sitchensis/32/4892_2.png) [@sitchensis](https://boards.straightdope.com/u/sitchensis)\ **Post date:** [October 8, 2015, 3:46pm UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/15 "2015-10-08T15:46:11Z")
> [@Telemark](#): > > NH alone has shifted from a low of 45% forest in the mid-1800s to 85% forested now. Maine has more forested land now (89%) but I don’t think it ever dipped as low as NH. Both states were around 90% forest before European settlers arrived. > > [New Hampshire Forests | Wildlife Journal Junior](http://www.nhptv.org/wild/nhforests.asp) In many cases the ground has been converted multiple times. Forest to farm, to forest, to being logged, back to forest. Trees live a long time compared to wheat, but even our fairly young country has had ample time for multiple rotations. ---
**Author:** ![Tom\_Tildrum](https://avatars.discourse-cdn.com/v4/letter/t/e95f7d/32.png) [@Tom\_Tildrum](https://boards.straightdope.com/u/Tom_Tildrum)\ **Post date:** [October 8, 2015, 3:53pm UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/16 "2015-10-08T15:53:33Z")
> [@msmith537](#): > > Like…never. > Don’t forget half of the worlds oxygen comes from the Ocean. Not sure why that made me think of King of the Hill… > [@](#): > > Hank: So are you Chinese or Japanese? > > Kahn: Laos. We are Laotian. > > Bill: You’re from the Ocean? ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [October 8, 2015, 3:53pm UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/17 "2015-10-08T15:53:56Z")
> [@Alley\_Dweller](#): > > Hmmm… This got me to thinking. > > When the weather is mild, the wholesale price of electricity on the grid often turns negative in the middle of the night. The electric generators can’t all be turned off, but nobody wants to buy the electricity they are producing. So the generation companies actually have to pay somebody to take the excess electricity off their hands. > > When the price of electricity is negative, could someone make a profit turning CO2 into O2? Could the generators save money by doing it themselves? No. It’s cheaper to just liquefy it from the air. You can curtail by electrolyzing water and mixing hydrogen into the natural gas distribution system for later use. I forget which countries are trying this. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [October 8, 2015, 3:59pm UTC](https://boards.straightdope.com/t/run-out-of-breathable-oxygen/733909/18 "2015-10-08T15:59:13Z")
> [@msmith537](#): > > I had read somewhere that the Northeast US is actually more forested now than it was back in the 1700s because back then it was all covered with farms. [Here’s](https://en.wikipedia.org/wiki/Deforestation_in_the_United_States#/media/File:Forest_land_trends_in_the_United_States,_1850-1997.png) a chart of historical deforestation levels for different regions of the US. For the northeastern US, the area of forest bottomed out in the early 1900s or so. It’s risen since, but not nearly to the levels pre-1800. The South and West have leveled off after previous declines.