It would be interesting to see man's relative destruction of O2 by varios means. Off hand I guess most of it is burning fossil fuels, mainly at ground level. Brazil does have some sugar cane alcohol powered crop duster air planes. They benefit from slightly greater HP produced compared to gasoline, but I'm too lazy to even compare the relative weight of a full fuel tank. Certainly gasoline gives greater range /air time, but for crop duster that is not impotant as must return for more of what it is spraying on crops, and can fill fuel tank then as well. It would be interesting to know how many acres of grass lands are needed to convert the CO2 one human exhales back into O2 for one "typical" person. Also another CO2 net zero release air plane could be electric with hydrogen* fuel cell - Has any one made one? There are a few small one or two passenger battery/ electric motor planes, so I think larger capacity may be possible with H2 -fuel instead of battery. * Generated from only wind or other solar energy.
I haven't seen any such reports. Photosynthesis alone generates more than 20x the amount of oxygen used by jet engines on aircraft. Also keep in mind that they exhaust CO2 - which is used by plants to generate oxygen. When there is more CO2 more oxygen is generated. (Indeed, if we weren't going so nuts with CO2 emissions, that mechanism would allow us to keep CO2 levels under control.)
Nor have I. Very likely entirely false due to constant Hadly and other circulation loops and relatively long mean free path diffusion at higher altitudes. Please Register or Log in to view the hidden image! O2 will be an ever smaller percent of the air and N2 a greater fraction high up. That is because on average both have the same kinetic energy at any altitude (same temperature) so the typical N2 molecule can "coast" higher up against the pull of gravity between collions. Is escaping toward space more rapidly. A heavy molecule will not get as high as fast. At very high altitude there is almost no gas left, but what is there will be more of the O2 than the N2 which did get earth escape velocity more frequently (only the very tiny high energy "tail" of the distribution function. - hope I got this logic correct. - too lazy to check with the facts.
Like this: Why yes. Exactly. The question is why you find that confusing. And my guess was and is this:
An interesting, if not weird, video satellite time lapse air traffic 2010 Unverified fact: "A 747 jet engine oxygen consumption rate is about 1,600 cubic feet per second when cruising at 32,000 feet." Live flight tracker as of 1pm AEST 03/03/2015 8840 flights in progress Please Register or Log in to view the hidden image! Say rough calculation assuming all flights are 747: 8500 * 1600cfs = 13,600,000 cubic feet of oxygen per second
I fail to see how man kind can possibly expect to burn up oxygen at the rate indicated (air traffic alone) in a closed system and expect that system to maintain integrity..yet this is exactly what appears to be happening. Add to this significant deforestation etc there can only be one outcome in the medium to long term... ( sorry going for a walk now and try to ignore our racial stupidity )
Yes, you are reading my concerns incorrectly. The part about co2 causes warming (and cooling) etc was sarcasm. Well the whole post was laden with sarcasm towards the news report/press release surrounding the paywalled paper. Carry on with your other discussions Please Register or Log in to view the hidden image!
Compare the amount of oxygen generated by photosynthesis throughout the world to the amount of oxygen consumed by aircraft. That's why we can expect the system to maintain integrity.
Unfortunately I am believer in the adage "No such thing as a free ride" when talking about a balanced system. Burn up a huge chunk of oxygen from a balanced eco system in an ongoing ever increasing daily fashion without replacing it and you are asking for trouble IMO. Having a play with the figures: 8500 * 1600cfs = 13,600,000 cubic feet of oxygen per second or about 562.9 US tons per sec 592.9 *60 = 35574 tons per minute 2134440 tons per hour 51226560 tons of oxygen per day 18,697,694,400 US tons per year (365 days) or 16,962,263,200,966 kgs O2 per year (8500 747's at 32000 feet) I also tend to believe that science is chronically underestimating how important a certain level of oxygen pressure is required to maintain healthy life forms. Inexplicable mass marine animal deaths. Hypoxia serious contender. Oceanic dead spots, (Hypoxia) Increasing incidence of Cardiovascular disease lung disease etc, could all be symptomatic of subtle changes in oxygen pressure levels in the atmosphere and in our oceans. I believe we humans are a lot more sensitive to this factor than we realize. Burning billions of US tons of oxygen pressure, annually in an eco system with out consideration could be having devastating effects on humans right now. Especially for those at peak stress levels.. etc
Short post that was here has been moved to end of: http://www.sciforums.com/threads/climate-gate.97892/page-96#post-3281631 to avoid "double posting."
Still neglecting the vertical circulation I illustrated with Hadley cell drawing I see. Perhaps text is more persuasive with you: I.e. airplnes are not big users of oxygen compared to other uses of fossil fuel that oxidize them. Sorry if you find the facts disturbing to your unfounded and false theories. You can just keep ignoring facts as you usually do. Isn't if about time to "re-cycle" your theory that global warming is caused by gravitational instability in the distant great attractor?
Agreed. Fortunately we are not burning up a huge chunk of oxygen from a balanced system. We are converting a SMALL part of the oxygen in the atmosphere into CO2. Since CO2 is toxic in even small percentages (over a few percent) we will hit that limit long, long before we start "running out" of oxygen. A few problems there. First off, that 1,600 cubic feet per second number is air, not oxygen, and it is at takeoff thrust. Air is only 20% oxygen, not 100%. At 30,000 feet, 13m cu ft of air is not 562 tons. A 747 at cruise altitude is not at takeoff power. A 747 uses JT9D's which are high bypass engines. For every five pounds of air it takes in, four pounds goes through the fan and straight out the back. The remaining pound is not completely burned, so only a small fraction of the oxygen is converted to CO2. This is one of the most heavily studied aspects of physiology, since it affects everything from air travel to mountain climbers to people living in Denver. It is quite well understood. Yes, due to algae blooms. There we are talking oxygen percentages of under 5%. Bubbling air through the water solves the problem, indicating it is not an atmospheric problem. The difference between living in LA and living in Denver is many orders of magnitude greater than any changes we've made to the atmosphere. Again, do the math.
No, it wasn't. Sarcasm was attempted, but to accomplish it one needs initial comprehension. For example, one could attempt sarcasm about media reports concerning elephants as follows: Elephants are male (and female) Elephants are dangerous (and useful) Elephants live in Africa (and Thailand) etc but this is not actual sarcasm. That's why there are no political satirists in the US right now who are both funny and "conservative". There are very funny "conservative" humorists - but not political ones. It's because you have to tell the, or a, truth, to be funny.
No, I think once is enough... and besides, if you can't grasp the universal nature of gravity then I see no point...
so this unverified fact is totally wrong? btw how many jet engines does a single 747 have? oh.. you have made my day... thanks.. phew! I can relax now... thanks. So we can be pretty certain, do you think , that we wont be having this discussion again in a few years?
Pretty sure. To be clear, I have no illusions that people are smart enough to not use too much oxygen. However, if we attempt to burn off all our fossil fuels as fast as we can, there are other things that will get astronomically worse (and indeed kill us off) before oxygen depletion becomes an issue.
yes true. I believe people in the air transport industry are very smart indeed when it comes to minimizing their impact on the atmosphere, and maximizing their profit margins. After all Oxygen is a renewable resource isn't it? (sarcasm Please Register or Log in to view the hidden image!) Oceanic dead zones clearly demonstrate recovery for hypoxia (more sarcasm Please Register or Log in to view the hidden image!) 2004 = 146 dead zones 2008 = 405 dead zones *Notes the absence of current data... last found report 2008 (according to wiki the pop encyclopedia )
well it stands to reason when you consider that the air is thinning as we go higher in altitude.. after all 23 % of air is 23% of air is it not?
Disagree! To burn fossil fuels one must also burn oxygen. Are you forgetting the typical air/fuel ratios needed for an typical automobile. If oxygen is 23 % of air, our fossil fuel burning in automotive use, alone, is also burning significant amounts of oxygen.