5 ms·
An average human breathes out roughly 1kg of carbon dioxide a day
- peterldowns 1y agoA related fun fact is that you generally lose weight by exhaling, generally while you sleep. Sweating, defecating, etc. is all temporary. If you're trying to lose weight, make sure you're sleeping enough! edit: see my followup comment, didn't mean to mislead here. I'm not a scientist and sleep and food science is both pretty hard to trust.
- brookst 1y agoWhy would you lose more weight with exhalations from relatively low sleeping metabolism than being awake? Not being contrary, genuinely curious.
- deff 1y agoIf I were to guess, the metabolism generates waste during activity that gets processed and exhaled as CO2 during sleep.
- robbiep 1y agoBad guess, I am not sure what OP really intends (perhaps you don’t consume whilst you sleep?!) because as you probably are starting to remember from primary school your body maintains homeostasis by continually respiring. It doesn’t suddenly decide to take a dump. Ok, it does, but even when it does that, in order to do that it has been continually maintaining homeostasis
- NAHWheatCracker 1y agoDoesn't the CO2 get exhaled during activity rather than sleep?
- amelius 1y agoYou exhale more CO2 during activity because metabolism increases. Burning glucose and fat produces CO2.
- deleted 1y ago[deleted]
- NAHWheatCracker 1y agoIt doesn't make sense that you would lose more weight by sleeping only considering metabolism. I can see an argument around sleeping always being a net loss, since you're never consuming food while sleeping. Sleeping more thus means you may eat less.
- peterldowns 1y agoSorry, my phrasing was not clear. Your metabolic rate is generally lower during sleep than during the day; you definitely lose more weight overall during the day than while asleep. But, while you're sleeping, you don't eat anything. And quality sleep is necessary to maintain overall metabolic function. I'm not a scientist and didn't mean to make any strong claims! Two short articles I was basing this off of: - "When somebody loses weight, where does the fat go?" https://www.bmj.com/content/349/bmj.g7257 https://www.bmj.com/content/349/bmj.g7257 - "Sleep and Metabolism: An Overview" https://pmc.ncbi.nlm.nih.gov/articles/PMC2929498/ https://pmc.ncbi.nlm.nih.gov/articles/PMC2929498/
- roter 1y agoIsn't the main reason because you're not eating?
- AlphaAndOmega0 1y agoYes. Sleep by itself does nothing unique. In fact, you have a slightly lower rate of metabolism than even the "basal" metabolic rate.
- AlphaAndOmega0 1y agoEh? That isn't right. The metabolic rate while asleep is even lower than the basal average. The only reason there's a net loss after sleep is because you're not regularly consuming food or water as you would when you're awake, not anything special about sleeping by itself. You're burning fewer calories than usual at that time!
- xnx 1y agoWe breathe in about 21 lbs. of air each day. This is much more than we eat each day! Important thing to think about in terms of how clean that air is.
- paulluuk 1y ago21 lbs -> 9.5 kg For those not working for the empire ;)
- justinrubek 1y agoThanks! I live in the empire and was born here. I still need metric measurements because I need to relate the numbers to real uses.
- kattagarian 1y agowithout javascript: https://xcancel.com/ID_AA_Carmack/status/1945948569246027934 https://xcancel.com/ID_AA_Carmack/status/1945948569246027934
- rs_rs_rs_rs_rs 1y agoThat's a lie, that page uses Javascript.
- reactordev 1y agoI love how he ends it with “thinking about space habitats” as I immediately thought: “well, if you can trap it and compress it, you’ll have enough briquettes for a weekly bbq”. He obviously knows this too. Dealing with human waste/by-product is a real challenge. Far more so in space than on an ocean or in an RV. We humans need to learn to use everything and not let anything go to waste. Else we have nothing left to waste.
- Sharlin 1y agoLuckily there are these things that take in CO2 and turn it into polymer structures with many uses such as food, fuel, and construction.
- cnity 1y agoNot to mention the oxygen we breathe to stay alive.
- jvanderbot 1y agoIf only we could turn that CO2 into food (C chains) and oxygen (O2) via some self sustainable self healing reproducing system that has an extremely low starting mass. A "co2 food producing seed" or something.
- cnity 1y agoI love this idea. If in some way the system produced more of the "seeds", and each of those "seeds" resulted in slightly different carbon chains, we could increase the diversity of the food in interesting ways. And if the system is large enough, and could be made beautiful, one could take a walk through the system. Call it a "forest".
- sambapa 1y agoAnd it would be mad if these "forests" would grow on a planet-sized spaceship with atmosphere and plenty of water, how cool and scifi would be that!
- bilsbie 1y agoDoes anyone know how to reduce this? I’m worried about creating climate change.
- 4hg4ufxhy 1y agoEat less. But don't worry.
- carlosjobim 1y agoDon't worry, the government already has plans in store for this particular issue.
- glitchc 1y ago[flagged]
- DennisP 1y agoNo, because activists have a basic understanding of the carbon cycle. All the carbon you exhale was recently taken out of the atmosphere by plants. You're carbon-neutral. If we start synthesizing food from fossil fuels, then human exhalation will actually contribute to climate change.
- conception 1y agoI think generally activists more don’t want billions to die from hunger, war and displacement and for the beauty we find in the world not to be spoiled. ¯\_(ツ)_/¯ But maybe you hang out with different activists.
- glitchc 1y ago> I think generally activists more don’t want billions to die from hunger, war and displacement and for the beauty we find in the world not to be spoiled. If you think that, then you experience the same cognitive dissonance that they do. The best way to despoil the world is to live like cavemen, which requires experiencing the hunger, disease and displacement that they did with far lower population counts from what we currently have. Conservatism is the antithesis of science and progress. Tree-huggers are anti-science and anti-progress.
- progx 1y agoAnd plants love it!
- throwaway3b03 1y agoFor comparison, a small ICE car produces around 100g of CO2/km, so with the same carbon budget you could drive 10km.
- bloak 1y agoThat comparison makes no sense because the ICE car is releasing carbon taken (mostly) from petroleum while the human is releasing carbon taken (mostly) from the atmosphere via plants and animals.
- deleted 1y ago[deleted]
- throwaway3b03 1y agoWell, years ago, I was running my indirectly injected diesel straight off sunflower oil, so that was plant based too. But your point is valid. Comparison is still useful for getting a grasp of the quantities involved.
- Muromec 1y agoBut only after you discard your mortal flash and upload your mind to a shiny Tesla-cloud. At which point you can probably afford to not care much about all the carbon problems anyway.
- bryanlarsen 1y agoSimilarly, burning a gallon of gasoline emits about 20 pounds of CO2. (2.3 kg/l). So daily human exhalations are equivalent to driving a couple of miles or so.
- jp57 1y agoTrue, but the gasoline is carbon taken from the air millions of years ago and sequestered underground and now being returned to the air, while the carbon I breathe out was all taken from the air by plants comparatively recently.
- bryanlarsen 1y agoThere was lots of diesel burned planting, harvesting and transporting those plants. Producing fertilizer also emits a lot of CO2.
- jp57 1y agoBut none of that carbon comes out in my breath.
- ColinWright 1y agoI wrote about this some time ago ... the calculations are here: https://www.solipsys.co.uk/new/CountingCarbonCalories.html?yg18hn https://www.solipsys.co.uk/new/CountingCarbonCalories.html?y... I'll submit that as a separate item ... Here: https://news.ycombinator.com/item?id=44605555 https://news.ycombinator.com/item?id=44605555
- goda90 1y agoA couple weeks ago mosquitos were at their peak in my yard. I started thinking about adult mosquito traps, but I don't love the idea of using propane as a CO2 source like most commercial solutions do. I casually looked into solar powered direct air capture of CO2, but that would not scale down. Then I realized maybe I could just capture my own exhalations for 30 minutes a day to use in a trap. Not sure I'll ever actually implement it.
- 0x000xca0xfe 1y agoHow about a tealight?
- kazinator 1y agoAt standard temperature and pressure 1 kg of CO2 has a volume of around 500 l. Exhaled air contains about 4% CO2, so you would have to exhale 12500 l of air to put out 500 l of CO2. At 0.5 l per exhalation that's 25,000 breaths, which seems rather on the high side: 17 breaths per minute, round the clock. It seems like a bit of a high estimate; could be true for people who are very physically active during parts of every 24 h period.
- xnx 1y ago> “thinking about space habitats” I think Carmack is a genius and admire his work ethic, but I can't understand what interests smart people like him about human space travel. Might be able to get more people excited about maintaining our amazing ecosystem if we talked about "Spaceship Earth" more.