[iacopo.russo (OP)]

According to estimates made by Naked Scientist Chris Smith in this article (https://www.bbc.com/news/magazine-16787636 [nofollow]), the Earth is losing mass.

Mike wrote to us to ask:

If the Earth overall is losing mass, the effect it has on gravity, however slight, may affect our atmosphere in a much different way than simply allowing hydrogen and helium to escape as a natural consequence. As we convert solid fuels (fossil and other) into heat, two factors occur at a minimum: release of hydrocarbons and infrared heat.  Add to this the loss of water stored in 3 trillion trees lost, and the amount of water vapor / heat being created by combustion is a SUBSTANTIAL NUMBER.

If the Earth is a bubble per se, inside an atmosphere containment, what is the result of increasing gaseous releases  and total heat / vapor produced by all combustion sources? What are the chances that the atmosphere is expanding relative to the stable size of the Earth itself, increasing atmospheric volume to store billions of tons of more water vapor?

What do you think?

[Zer0]

Perhaps the Atmosphere will expand & extend to engulf the Moon.

Probably a Good Thing Earth is getting Lighter.
(Drastically slow)

Ps - Let's Go Elon Musk!!!
🖖

[chiralSPO]

Perhaps the Atmosphere will expand & extend to engulf the Moon.

Not in any meaningful way, thankfully!

If the Earth overall is losing mass, the effect it has on gravity, however slight, may affect our atmosphere in a much different way than simply allowing hydrogen and helium to escape as a natural consequence.

Well, yes, you're right that decreasing the mass of the earth will naturally lead to a lower surface pressure, and allow the atmosphere to puff out a little more. I think it's important to consider the magnitudes involved though. The change in mass that we can expect the earth to have over the next several centuries is a fraction of a fraction of a fraction of a percent. This will not have a significant effect on the composition or mass of the atmosphere.

As we convert solid fuels (fossil and other) into heat, two factors occur at a minimum: release of hydrocarbons and infrared heat.  Add to this the loss of water stored in 3 trillion trees lost, and the amount of water vapor / heat being created by combustion is a SUBSTANTIAL NUMBER.

The heat being released by burning fossil fuels is surprisingly insignificant compared to the heat budget of the earth. (One full 24 hours of sunlight on the whole earth is many times greater than all of the heat produced by all of our power plants and cars and industry etc. in an entire year!)

But the generation of carbon dioxide, and to a lesser extent, water, is significant. The amount of water in the atmosphere is essentially a function of how warm it is (higher temperatures allow more water to be in the vapor form), so producing a bunch of water vapor doesn't necessarily mean that the atmosphere will get more massive (it may just lead to more precipitation).

With carbon dioxide the story is different. There is some degree of solubility in water which is temperature-dependent, but the solubility of carbon dioxide in water is not very high, so most of the carbon dioxide that is produced does go into the atmosphere.

The atmosphere used to have LOTS of carbon dioxide. Before photosynthetic organisms there was no significant concentration of molecular oxygen in the atmosphere: basically, for every molecule of oxygen in the atmosphere now, there is an atom of carbon buried in the ground in the form of fossil fuel, and it used to be a molecule of carbon dioxide in the atmosphere (and the atmosphere is currently about 20% oxygen, and 0.0004% carbon dioxide)

And before THAT, there were a bunch of microorganisms that pulled carbon dioxide out of the atmosphere to make their calcium carbonate shells. As they died, their shells piled up and eventually became the limestone deposits that cover the earth (limestone is basically just crushed ancient microbe exoskeletons). That was a LOT of carbon dioxide.

[Petrochemicals]

I believe a hotter atmosphere and increaced co2 will increace the atmosphere, also the fraction of fixated energy as mass when released will also lower the mass of earth.

The heat being released by burning fossil fuels is surprisingly insignificant compared to the heat budget of the earth. (One full 24 hours of sunlight on the whole earth is many times greater than all of the heat produced by all of our power plants and cars and industry etc.)

much of the solar radiation is returned to space, hence why all the furore over a slight increace in co2, which is a tiny proportion of the atmosphere.

But the generation of carbon dioxide, and to a lesser extent, water, is significant. The amount of water in the atmosphere is essentially a function of how warm it is (higher temperatures allow more water to be in the vapor form), so producing a bunch of water vapor doesn't necessarily mean that the atmosphere will get more massive (it may just lead to more precipitation).

water also has "greenhouse" properties and is there in significant quantities.

[chiralSPO]

much of the solar radiation is returned to space, hence why all the furore over a slight increace in co2, which is a tiny proportion of the atmosphere.

For the Earth to remain at thermal equilibrium the amount of energy radiated to space must equal the amount of energy that comes in (mostly from the sun, but there is also some geothermal energy too). If the amount of energy that is radiating out is less than the amount coming in, the average temperature on earth will increase until the the balance is re-established (hotter objects radiate more). So any change in how effectively the atmosphere allows heat out (no matter how small) will also result in a change in the average temperature on earth. It turns out that even very small changes in average temperature have significant changes on climate. Hence the furor.

water also has "greenhouse" properties and is there in significant quantities.

Yes. But there hasn't been a major change in the amount of water available to the atmosphere recently (other than driven by climate*). We have increased the amount of available carbon dioxide by more than 35% in the last 100 years (and methane by 100%)

*As the temperatures increase, more water vapor gets into the atmosphere, increasing the greenhouse effect of the atmosphere, but there are also complications with cloud cover, snow/ice distribution, and heat distribution... so unlike co2, where it's a simple more co2 means stronger greenhouse effect and more warming, with water, there is no simple relationship.

[Petrochemicals]

much of the solar radiation is returned to space, hence why all the furore over a slight increace in co2, which is a tiny proportion of the atmosphere.

For the Earth to remain at thermal equilibrium the amount of energy radiated to space must equal the amount of energy that comes in (mostly from the sun, but there is also some geothermal energy too). If the amount of energy that is radiating out is less than the amount coming in, the average temperature on earth will increase until the the balance is re-established (hotter objects radiate more). So any change in how effectively the atmosphere allows heat out (no matter how small) will also result in a change in the average temperature on earth. It turns out that even very small changes in average temperature have significant changes on climate. Hence the furor.

obviously it has to attain equilibrium, for the temperature to remain equal, hence the meaning. Most of the solar radiation is reflected or reemmitted into space without having any effect on the temperature of the earth which means it has no effect on the atmospheric expansion

water also has "greenhouse" properties and is there in significant quantities.

Yes. But there hasn't been a major change in the amount of water available to the atmosphere recently (other than driven by climate*). We have increased the amount of available carbon dioxide by more than 35% in the last 100 years (and methane by 100%)

*As the temperatures increase, more water vapor gets into the atmosphere, increasing the greenhouse effect of the atmosphere, but there are also complications with cloud cover, snow/ice distribution, and heat distribution... so unlike co2, where it's a simple more co2 means stronger greenhouse effect and more warming, with water, there is no simple relationship.

Yeh, the first part contravenes the second part, you are not getting away with that.  I'll remind you, green house effect is to do with long wave solar radiation that is not filtered by the atmosphere, being reflected  or re-emitted from earth as short wave radiation that is filtered by the atmosphere, water and co2 primarily plus methate etc.

Higher temperature, greater water bearing capacity, more water vapour, more greenhouse effect, higher temperature.

[Bored chemist]

I'll remind you, green house effect is to do with long wave solar radiation that is not filtered by the atmosphere, being reflected  or re-emitted from earth as short wave radiation that is filtered by the atmosphere, water and co2 primarily plus methate etc.

Did you read that through before you posted it?

[Zer0]

I'll remind you, green house effect is to do with long wave solar radiation that is not filtered by the atmosphere, being reflected  or re-emitted from earth as short wave radiation that is filtered by the atmosphere, water and co2 primarily plus methate etc.

Did you read that through before you posted it?

I guess Not!
(Sounds like someone has rheumatoid arthritis of the brain)

[chiralSPO]

Most of the solar radiation is reflected or reemmitted into space without having any effect on the temperature of the earth

Again... ALL of it is eventually emitted to space, but between when it arrives and when it departs, it is part of earth's energy budget. Earth's albedo is somewhere around 0.3, so just under a third of the (visible) light is immediately reflected. The rest will have to take the long way out, enjoying the majority of its stay as heat. The more co2 is in the atmosphere, the longer the stay. (And it hardly reduces the amount of incoming energy, so overall it is a greenhouse gas).

[Petrochemicals]

Most of the solar radiation is reflected or reemmitted into space without having any effect on the temperature of the earth

Again... ALL of it is eventually emitted to space, but between when it arrives and when it departs, it is part of earth's energy budget. Earth's albedo is somewhere around 0.3, so just under a third of the (visible) light is immediately reflected. The rest will have to take the long way out, enjoying the majority of its stay as heat. The more co2 is in the atmosphere, the longer the stay. (And it hardly reduces the amount of incoming energy, so overall it is a greenhouse gas).

At 0.3  reflected the negligible increase in a miniscule co2 component of the atmosphere, that would mean earth absorbs the 0.7? . This is someone's recconing of Earth's energy 
fOHdxLaNSzSeaXNxR34l_Solar Energy Budget.gif (37.31 kB . 744x556 - viewed 4205 times)

[chiralSPO]

Most of the solar radiation is reflected or reemmitted into space without having any effect on the temperature of the earth

Again... ALL of it is eventually emitted to space, but between when it arrives and when it departs, it is part of earth's energy budget. Earth's albedo is somewhere around 0.3, so just under a third of the (visible) light is immediately reflected. The rest will have to take the long way out, enjoying the majority of its stay as heat. The more co2 is in the atmosphere, the longer the stay. (And it hardly reduces the amount of incoming energy, so overall it is a greenhouse gas).

At 0.3  reflected the negligible increase in a miniscule co2 component of the atmosphere, that would mean earth absorbs the 0.7? . This is someone's recconing of Earth's energy   [ Invalid Attachment ]

This image looks reasonable to me. As you can see about 30% of the light is reflected (6% atmosphere + 20% clouds + 4% ground 6+20+4 = 30). Increasing CO₂ will not significantly change the percent reflected (or the amount of time it takes the reflected light to leave), and it will not change the amount of energy that gets radiated out into space (it's still the other 70%), but it will take longer for that energy to get out because the CO₂ will absorb some of the outgoing radiation and then radiate it a random direction (probably not the same as the initial one), or it will get truned back into heat through non-radiative processes.

[chiralSPO]

Higher temperature, greater water bearing capacity, more water vapour, more greenhouse effect, higher temperature.

Yes, to some extent. But also more water vapor, more clouds, more reflection of sunlight before it gets to the ground, but also more heat retained at night. My understanding is that the overall net effect of water vapor is also going to depend on how much carbon dioxide and methane we put up there (the reflection of sunlight is much more important and retention of heat much less important if the greenhouse effect is very strong).

Water also cannot be the forcing aspect of climate change, even if it does end up having a positive feedback loop to it. It's the carbon dioxide that is pushing the loop, and if we reign that in we can limit or even (eventually) reverse the change.

[Petrochemicals]

That picture shows that only 30 percent of the sun's energy entering the earth system, 23 percent in the latent heat of water evaporation and 7 percent in convective conductance. The remaining 70 percent is either reflected (30%) or re emitted into space somehow (40%). 30 percent into the system is still very very large as it is the solar radiation.  I understand that the system reaches equilibrium by venting all the energy into space eventually.

The planet holds much energy, forgoing the small internal energy from radioactive decay, the earth is subsidised to roughly 300 kelvin throughout, the core of the earth retaining some of its primeval heat.

[Bored chemist]

Again... ALL of it is eventually emitted to space

Not quite, some goes into warming the place up.
That's the important bit.

[chiralSPO]

That picture shows that only 30 percent of the sun's energy entering the earth system, 23 percent in the latent heat of water evaporation and 7 percent in convective conductance. The remaining 70 percent is either reflected (30%) or re emitted into space somehow (40%).

That's not how I interpret the diagram. 100% comes in from the sun. Of that, 30% is reflected immediately, without contributing to the energy budget on Earth. The remaining 70% does all manner of things; and it really doesn't matter what happens to it, due to conservation of energy, it will just convert from one form to another until it is eventually radiated out to space.

Not quite, some goes into warming the place up.
That's the important bit.

The important bit is that the amount of energy at any given time is increasing. The flux of energy coming in is currently ever-so-slightly greater than the flux going out, but every bit in eventually gets out.

We could model it in such a way that there is some fraction that gets permanently stuck, and that's nice and easy for accounting, but it doesn't aline nicely with the actual physical processes responsible for the greenhouse effect, and that then leaves the argument open to pedantic (and often bad-faith) arguments.

[Petrochemicals]

That picture shows that only 30 percent of the sun's energy entering the earth system, 23 percent in the latent heat of water evaporation and 7 percent in convective conductance. The remaining 70 percent is either reflected (30%) or re emitted into space somehow (40%).

That's not how I interpret the diagram. 100% comes in from the sun. Of that, 30% is reflected immediately, without contributing to the energy budget on Earth. The remaining 70% does all manner of things; and it really doesn't matter what happens to it, due to conservation of energy, it will just convert from one form to another until it is eventually radiated out to space.

I read it as 30 percent reflected radiation, 40 percent reemmitted radiation, 7 percent convection and conduction, 23 percent latent heat of evaporation of water.

[Bored chemist]

The flux of energy coming in is currently ever-so-slightly greater than the flux going out, but every bit in eventually gets out.

OK. Where is the energy coming from that heats the Earth?
Because it really is warming up.
https://climate.nasa.gov/news/2241/why-so-many-global-temperature-records/

The heat from radioactive decay is (very slowly) falling, and the primordial heat is (very slowly) dissipating.
The Sun doesn't seem to have got brighter.
But the temperature has gone up, and that's because we have trapped more of the heat.

Over some timescale, it will cool again but the heat death of the universe isn't what people are talking about in this context.

[Bored chemist]

23 percent latent heat of evaporation of water.

What do you think happens to this heat?

[chiralSPO]

The flux of energy coming in is currently ever-so-slightly greater than the flux going out, but every bit in eventually gets out.

OK. Where is the energy coming from that heats the Earth?
Because it really is warming up.
https://climate.nasa.gov/news/2241/why-so-many-global-temperature-records/

The heat from radioactive decay is (very slowly) falling, and the primordial heat is (very slowly) dissipating.
The Sun doesn't seem to have got brighter.
But the temperature has gone up, and that's because we have trapped more of the heat.

Over some timescale, it will cool again but the heat death of the universe isn't what people are talking about in this context.

Obviously, the energy is primarily coming from the sun, and the increasing temperature has to do with the fact that the changing composition of the atmosphere is decreasing the rate at which energy can leave. I am fairly confident you know what a steady state is... if it were trackable, what do you think the average dwell time is of the energy in the earth system?

The energy flowing in and out of the earth system is analogous to the water flowing through a length of river, given a very constant source of water. When at steady state equilibrium, flux of water in = flux of water out, and the level of the river remains constant. If the downstream end of the length of interest is narrowed, then to maintain a steady state the water must either flow more quickly or become deeper (maintaining the cross sectional area). In our analogy there is no meaning to the former, so I will focus on the latter: by adding greenhouse gasses to the atmosphere, we are essentially pinching off the flow of energy out, narrowing that river at point of efflux. Since energy (water) is pouring in at the same rate, the depth in the length of interest will increase until the steady state is re-established.

Note that I don't have to talk about water getting trapped in the river. It's not trapped, it still flows freely. But clearly the increase in depth of the river is a direct result of the change in how wide the exit is. This increased depth (if it wasn't clear already) represents the increased thermal energy in the earth system.

Isn't this easier to understand and defend than invoking some sort of abstract "trap" holding on to the excess heat?

[Bored chemist]

It will reach a steady state where the average power in is the same as the average power out, but there will have been a net increase in the Earth's energy to make it hotter. And there's only one place that energy came from.