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In a closed system like Earth, is cold air at the geographical scale a non-renewable resource? Meaning once we warm up all the air, is there a way to make more
by xwdv 3y ago
In a closed system like Earth, is cold air at the geographical scale a non-renewable resource? Meaning once we warm up all the air, is there a way to make more cold air again at significant scales?
- WillPostForFood 3y agoThe Earth isn't a closed system. Most of the heat that is getting trapped by C02 is coming from the sun, and we continually bleed atmosphere into space. The average temp of the universe is -455F, so cold is the most abundant resource.
- epolanski 3y agoTechnically speaking I don't think you can measure the "temperature of the universe". Temperature depends on the kinetic energy of a certain amount of whatever molecules, but the universe is essentially empty/void, thus there's nothing really to measure the temperature of. I know that it isn't strictly empty/void, but for a temperature related measurement it essentially is.
- roywiggins 3y agohttps://bigthink.com/starts-with-a-bang/universe-temperature/ https://bigthink.com/starts-with-a-bang/universe-temperature... > in the deepest depths of intergalactic space — an object placed there would gain or lose energy until it reached the background temperature of that light left over from the Big Bang: 2.725 K.
- mrguyorama 3y agoWhile true, it would take a very very long time. There simply are not enough molecules of anything in "space" to effectively and efficiently transport heat, and we even struggle to keep craft in space cool because the only reliable source of heat transfer is black body radiation from your craft. The heat capacity of space is nearly non-existent.
- epolanski 3y agoThere's a problem with that: there's really nothing much to transfer heat to in the universe's voidness, thus the heat dissipation would be insanely slow.
- quchen 3y agoTo add to the other comment mentioning the cosmic microwave background, consider that thermometers measure _their own_ temperature, not the one of their surroundings. This nitpick is actually important here, because it explains how temperature can be measured even in complete (massive+free particle) vacuum. Whenever there is energy transfer into the thermometer, and the CMB does just that, you measure temperature. Related fun fact: the vacuum of space is not only very very cold, but also very insulating. Space suits have to be fitted with a cooling system, otherwise the heat of the astronaut's body and suit electronics would become too warm, even though it's 2.7K all around them.
- j-bos 3y agoBy blocking heat I imagine. Wasn't this the case with the old cargo deisel standards? First link I found: https://www.carbonbrief.org/analysis-how-low-sulphur-shipping-rules-are-affecting-global-warming/ https://www.carbonbrief.org/analysis-how-low-sulphur-shippin...
- kalupa 3y agoI think an enormous amount of heat is radiated into space
- SideburnsOfDoom 3y agoAlso, an enormous amount of heat is radiated in from space during the day.
- jmoak3 3y agoWe radiate heat into space at all times
- r3trohack3r 3y agoJust taking since life developed, our planet has been being hit by sun for 4.2bn years. If Earth had no way of dissipating heat, we’d have burned to a crisp by now. No?
- Brusco_RF 3y agoEarth is a blackbody[1]. We receive heat from the sun in the form of radiation. We also radiate heat out to space. [1] https://en.wikipedia.org/wiki/Black-body_radiation https://en.wikipedia.org/wiki/Black-body_radiation
- Timon3 3y agoNo, the earth is not a black-body. As your link says: > Of particular importance, although planets and stars (including the Earth and Sun) are neither in thermal equilibrium with their surroundings nor perfect black bodies, black-body radiation is still a good first approximation for the energy they emit.
- Brusco_RF 3y agoAll models are incorrect, but some are useful. Fine, you win Timon3, earth is not a blackbody because blackbodies don't actually exist.
- Timon3 3y agoThank you! Party this evening at my place. It's fine to say "the earth behaves similarly to a black-body" or "a black-body is a good approximation for the earth". But that's different from "the earth is a black-body".
- bitcurious 3y agoThought experiment - you could look at life itself as a form of heat management. Consider oil: crudely speaking, it's energy that could have heated some bit of the ocean, but instead was captured by a cell via photosynthesis which died and got buried underground.
- magospietato 3y agoHeat is constantly lost to space as infrared radiation. The greenhouse effect slows this loss, and is driven by the output of "greenhouse gases" into the atmosphere. These gasses absorb the infrared that would be lost to space, retaining them inside the "closed system". Greenhouse gasses have natural sources, but far and away the largest sources are manmade in the form of carbon dioxide as industrial byproduct, and methane as agricultural byproduct. This is why experts are so concerned: stopping production of manmade greenhouse gasses will not immediately reduce the amount of those gasses in the atmosphere, so heating will likely continue for many years after peak output.
- PartiallyTyped 3y agoEDIT: Apparently I typed the opposite thing of what I intended :upside_down:
- SonicScrub 3y agoI think you need to crack open a Thermodynamics textbook and re-lookup the definition of "open" and "closed" systems. Open systems are certainly capable of maintaining stable heat-balances, where net energy outflow equalizes to net heat inflow.
- PartiallyTyped 3y agoThe "not" was a mistype :( ... I meant that had earth been closed, then the temperature would be fixed and life [eventually] wouldn't be possible.
- davis 3y ago> stopping production of manmade greenhouse gasses will not immediately reduce the amount of those gasses in the atmosphere, so heating will likely continue for many years after peak output Regarding the stopping of manmade greenhouse gasses, the consensus has been changing over the last few years though and it's pretty wildly believed that the "heat in the pipeline" phenomenon isn't actually true. Here's the best summary on why zero emissions will mean an immediate end to global warming: https://www.carbonbrief.org/explainer-will-global-warming-stop-as-soon-as-net-zero-emissions-are-reached/ https://www.carbonbrief.org/explainer-will-global-warming-st...
- csours 3y agoIf you have an infrared thermometer (they commonly have a pistol grip and laser pointer), take it outside at night and point it up. A couple days ago in central Texas at 10 pm, the air temperature at ground level was 90 F, but the temperature above was 60 F. As a comparison, last year on the same date it was 100F at ground level and 83F in the sky. In winter, on a moderately cold day of 30 F, the sky temperature is as low as -50 F. This radiant temperature has a huge effect on the "Feels Like" temperature, especially if you're not in direct sunlight. In other words, the Earth is always radiating heat away, and at night it radiates faster than it gets heated up. I'd like to collect this data automatically to see how it changes over a season.
- dragonwriter 3y ago> In a closed system like Earth Holy bad starting premise, Batman.
- jacquesm 3y agoHehe, ok, thank you for lightening the mood a bit in this thread, I had a good chuckle at that (and now have to deal with people staring at me).
- AndrewKemendo 3y agoThe earth isn't a closed system and has a "Energy Budget": https://scied.ucar.edu/learning-zone/how-climate-works/energy-budget https://scied.ucar.edu/learning-zone/how-climate-works/energ... Humans have decreased the rate that the earth dissipates heat into space, and even small changes can cause large feedback loops that we care about because Humans can only survive within a TINY threshold of temperature variance [1]. Over the long term (~100-200k years) it will probably go back to some kind of pre-human equilibrium - with the very long term earth being mathematically uninhabitable based on the increasing amount of radiation that will bombard the earth as the Sun goes Red Giant. [1]https://twitter.com/AndrewKemendo/status/1681703538181668869 https://twitter.com/AndrewKemendo/status/1681703538181668869
- coryrc 3y ago> Humans can only survive within a TINY threshold of temperature variance Don't be obtuse.
- 4gotunameagain 3y agoWell he has a point. Humans survive from what, -40C to 40C ? Given Earth's record temperatures of -89.2C to 56.7C, sure, we can survive in a large chunk, but the mean temperature of cosmic gas is 2.2 million deg C
- coryrc 3y agoWhen talking about climate, it is not relevant that we are unable to live in the sun.
- 4gotunameagain 3y agoWhen talking about planetary temperatures, it is relevant that we cannot live in Venus, at 475C, or Mars, -60C. It is not inconceivable that we mess things up so much that peak temperatures move by double digits, in which case it will be evident if our temperature range is tiny or not
- Zigurd 3y ago"Geoengineering" is what that's called. You can put chemicals in the atmosphere to make it hold less heat, or in the water to encourage algae to use more CO2, or put a sunshade in orbit, etc. I think that is discussed less than it should be. I think people avoid the topic because it is of course hugely risky. I would bet that will change because the risk of continuing fossil fuel use is so high and so uncontrollable.