Viewing a single comment thread. View all comments

furtherdimensions t1_j9q39yx wrote

We have slightly more atmosphere than we used to. That's really the short answer to it. We added "stuff" without taking away "stuff". So we have more "stuff". A little bit more. Not a lot.

Which doesn't sound like much but little changes can have major impact to life that's evolved to a very narrow band of conditions.

1

Way2Foxy t1_j9qevw0 wrote

well that's not how combustion works

5

furtherdimensions t1_j9qg0cv wrote

...what? were you under the impression clouds are just big fluffy white pieces of coal?

−2

Way2Foxy t1_j9qjb4g wrote

Where are you supposing we source most of that O2 in CO2?

1

furtherdimensions t1_j9qnqep wrote

....so oxygen bonds to carbon and releases energy and co2. We took oxygen, added carbon that was stored in physical matter, and released it as co2. So oxygen was removed, bonded with carbon, and released back into the atmosphere this time with added carbon.

So the net amount of oxygen atoms remains the same but we've now added carbon.

The carbon is "stuff". We've taken away no net oxygen atoms and we've added carbon.

You understand that 1-1+1+2 is the same as 1+2 right? Am I assuming correctly that this is at least something you get? Do I need to slow down?

1

konwiddak t1_j9r6hx6 wrote

The CO2 weighs more but has the same volume as the O2 it replaced. However you've missed the face we've also burned a bunch of hydrogen since almost everything we burn is a hydrocarbon. This produces water (H2O) which precipitates out of the atmosphere with a net result of depleting the amount of oxygen atoms in the air. (See my longer answer).

2

konwiddak t1_j9r455s wrote

I see your logic, and at first glance I was about to defend your statement, however it's not correct because:

  1. If you burn pure carbon, you get O2 + C = CO2. That's the same number of gas molecules after burning. 1 gas molecule in the input, 1 gas molecule on the output. A gas's volume is determined by temperature and number of molecules, not the number of atoms(technically an approximation, but a very good one). Yes there are more atoms making up the gas, but once the combustion gas has cooled to ambient, the volume of CO2 is basically the same as the volume of O2 you started with. While the CO2 is heavier, this doesn't equate to more gas, it's just heavier gas. (If I give you a litre of petrol and a litre of water, you've got the same amount, although the water weighs more.)

However this is kind of moot because:

  1. All this combustion can actually make he atmosphere weigh less and have a lower volume! Most of the stuff we burn is a hydrocarbon. Hydrocarbons burn to produce CO2 and H2O. The H2O precipitates out of the atmosphere, so there's actually fewer gas molecules in the air because we've removed oxygen and turned it in to water. In addition, the mass of the oxygen precipitated, is greater than the mass of carbon added, so the air is lighter too. Now it really depends what hydrocarbons we've burned. Natural gas (methane) produces twice as many water molecules as CO2 so would have the strongest depleting effect. Liquid fuels like petrol, diesel and oil produce about equal numbers of CO2 and water molecules so more slightly deplete the atmosphere. Coal produces fewer water molecules than CO2 I haven't done the math on whether this is a net mass increase or decrease (I expect it's pretty mass neutral) but it definitely still decreases the air's volume.
3

MagicPeacockSpider t1_j9r692z wrote

H20 joins the precipitation cycle but due to increasing temperatures there is more H2O in the atmosphere than before on average.

So yes. We do have more atmosphere than before.

Both by mass and by number of molecules.

The energy we've put into the system will eventually go back to the previous equilibrium after hundreds of years. So it's temporary on the earth's timescale at the moment.

Unless we put too much energy in then it releases more energy, methane released, ice caps melted, less heat reflected, and the change becomes more of an earth timescale one than a human timescale one.

1

lackadaisical_timmy t1_j9qia01 wrote

That is impossible lol. We didn't "add stuff without taking away stuff".

2

MagicPeacockSpider t1_j9r5xvn wrote

We turned solid stuff (Hydrocarbons) into atmosphere. CO2 and H20

The volume of both of those things in the atmosphere has increased.

There are literally tons of Carbon released into the atmosphere and while it will come down eventually we do have more atmosphere than before.

1