3 ms·

> The oxygen drop is driven by a few factors. First, the laws of physics dictate that warmer water can hold less dissolved gas than cooler water (this is why a

> The oxygen drop is driven by a few factors. First, the laws of physics dictate that warmer water can hold less dissolved gas than cooler water (this is why a warm soda is less fizzy than a cold one). > Melting ice adds fresh, less-dense water that resists downward mixing in key regions, and the high rate of atmospheric warming at the poles, as compared to the equator, also dampens winds that drive ocean currents. > Finally, bacteria living in the water, which feed off phytoplankton and other organic gunk as it falls to the seafloor, consume oxygen. This effect can be massive along coastlines, where fertilizer runoff feeds algae blooms, which in turn feed oxygen-gobbling bacteria

NovaDudely 3y ago
So there is this idea that we can reduce the CO2 in the atmosphere by using iron seeding into the ocean causing a massive amount of phytoplankton production. But would the side effect of this be a drop in ocean oxygen levels?
- myshpa 3y ago
  It's imho always better to let the nature do the job. Just stop interfering.
- rcme 3y ago
  No it would increase ocean oxygen levels. CO2 in the atmosphere would become O2 in the ocean and carbon in the phytoplankton. Until the plankton decay, of course.
DoctorOetker 3y ago
As water heats, the solubility of solids (salts, sugars, etc.) goes up. As water heats, the solubility of gases (O2, CO2, etc.) goes down. Humanity coming from initial blissful ignorance about CO2 emissions eventually became concerned about rising atmospheric CO2. Most emitted CO2 was actually being absorbed by oceans. This also makes the ocean acidic. So the oceans acted like a "landfill" buffering a large amount of CO2 emissions. Consider a duplicate earth, where Carbon is added to atmospheric O2 oxygen molecules. As long as its surface waters are not saturated with CO2, it can buffer a large fraction of the resulting CO2, with an equilibrium constant between aqueous CO2 and atmospheric CO2. At a certain point this "CO2 landfill" or rather "CO2 seafill" saturates. Assuming for simplicity a constant CO2 emission rate, thus without increasing the rate of CO2 emission, atmospheric CO2 rises at an initial rate (slower than CO2 emission rate, since a large fraction is initially absorbed by the ocean surface waters); until surface waters are (near) saturation, at which point atmospheric CO2 starts rising at a much higher rate since the surface waters no longer absorb significant amounts of CO2. If one then desparately and miraculously succeeds in somehow halting continued excess CO2 emissions, the globe will still heat due to the added atmospheric CO2, also heating these surface waters, decreasing gaseous solubilities, resulting not just in aqueous O2 depletion but also sadly in "CO2 blowback": the large fraction of CO2 historically dissolved in the surface waters turns back into the atmosphere, even though miraculously excess antropogenic CO2 emissions were halted! From a "carbon credits" perspective, where players are traditionally viewed as nations and corporations, surface waters rear their head and releases the historical CO2 debth.
- nashashmi 3y ago
  Excess CO2 in surface water causes algae and phytoplankton blooms that feeds back into sealife. The CO2 is not being released once the water warms. Rather the waters are becoming more acidic and therefore "tastier".
  - DoctorOetker 3y ago
    https://en.wikipedia.org/wiki/Carbonate#Buffer https://en.wikipedia.org/wiki/Carbonate#Buffer The first paragraph is written as if it only applies to blood, but chemical equilibria are of course more general, as acknowledged in the second paragraph starting with "Crucially, a similar buffer operates in the oceans." Observe that the arrows for 1, 2 and 3 go both ways, and so represent reversible equilibrating reactions. Perhaps you would like sweet seawater instead of salty seawater, but obviously taste can not be argued. Facts however can.

NovaDudely 3y ago

So there is this idea that we can reduce the CO2 in the atmosphere by using iron seeding into the ocean causing a massive amount of phytoplankton production. But would the side effect of this be a drop in ocean oxygen levels?

myshpa 3y ago
It's imho always better to let the nature do the job. Just stop interfering.
rcme 3y ago
No it would increase ocean oxygen levels. CO2 in the atmosphere would become O2 in the ocean and carbon in the phytoplankton. Until the plankton decay, of course.

DoctorOetker 3y ago

As water heats, the solubility of solids (salts, sugars, etc.) goes up. As water heats, the solubility of gases (O2, CO2, etc.) goes down. Humanity coming from initial blissful ignorance about CO2 emissions eventually became concerned about rising atmospheric CO2. Most emitted CO2 was actually being absorbed by oceans. This also makes the ocean acidic. So the oceans acted like a "landfill" buffering a large amount of CO2 emissions. Consider a duplicate earth, where Carbon is added to atmospheric O2 oxygen molecules. As long as its surface waters are not saturated with CO2, it can buffer a large fraction of the resulting CO2, with an equilibrium constant between aqueous CO2 and atmospheric CO2. At a certain point this "CO2 landfill" or rather "CO2 seafill" saturates. Assuming for simplicity a constant CO2 emission rate, thus without increasing the rate of CO2 emission, atmospheric CO2 rises at an initial rate (slower than CO2 emission rate, since a large fraction is initially absorbed by the ocean surface waters); until surface waters are (near) saturation, at which point atmospheric CO2 starts rising at a much higher rate since the surface waters no longer absorb significant amounts of CO2. If one then desparately and miraculously succeeds in somehow halting continued excess CO2 emissions, the globe will still heat due to the added atmospheric CO2, also heating these surface waters, decreasing gaseous solubilities, resulting not just in aqueous O2 depletion but also sadly in "CO2 blowback": the large fraction of CO2 historically dissolved in the surface waters turns back into the atmosphere, even though miraculously excess antropogenic CO2 emissions were halted! From a "carbon credits" perspective, where players are traditionally viewed as nations and corporations, surface waters rear their head and releases the historical CO2 debth.

nashashmi 3y ago
Excess CO2 in surface water causes algae and phytoplankton blooms that feeds back into sealife. The CO2 is not being released once the water warms. Rather the waters are becoming more acidic and therefore "tastier".
- DoctorOetker 3y ago
  https://en.wikipedia.org/wiki/Carbonate#Buffer https://en.wikipedia.org/wiki/Carbonate#Buffer The first paragraph is written as if it only applies to blood, but chemical equilibria are of course more general, as acknowledged in the second paragraph starting with "Crucially, a similar buffer operates in the oceans." Observe that the arrows for 1, 2 and 3 go both ways, and so represent reversible equilibrating reactions. Perhaps you would like sweet seawater instead of salty seawater, but obviously taste can not be argued. Facts however can.