We got this out in the oceans:
"To summarize this section, the recent discovery of the marine Prochlorococcus has identified an enormous new source of oxygen on planet Earth. The implications are not yet fully understood but must be substantial."
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8960603/
This organism seems to like subtropical latitudes which are expanding northwards and southwards.
If it takes advantage of the greater light exposure and increasing CO2, atmospheric oxygen levels will increase.
Currently, oxygen levels are at 21%, but above 23% wildfires become uncontrollable.
There was a time, the carboniferous, when oxygen levels and CO2 were high and wildfires were basically everywhere, all the time.
So here we have another potential positive feedback loop, and I am very unhappy about it involving a microorganism prone to exponential proliferation, and an ongoing increase in atmospheric CO2 that acts as a fertilizer for wildfire fuel (forests and other biomass).
Yes, the campfire comparison is kind of uninformed given that being terminally choked out by smoke isn´t a completely unrealistic scenario.
Looks like there is new evidence for increasing abundance of phytoplankton in the oceans in the tropical/subtropical belt.
Briefly, during the Carboniferous period atmospheric oxygen and carbon dioxide were very high and there were vast tropical rain forests/swamps covering extensive tropical lowlands.
These forests were continually burning due to the elevated atmospheric O2 and the abundance of fuel biomass (the abundance of fuel might have been boosted by the absence of wood (lignin) digesting organisms).
But not all wood was burned - a lot got buried in oxygen free swamps and got converted to coal.
The ongoing sequestration of organic carbon left oxygen behind, and thus maintained elevated atmospheric oxygen level in a sort of steady state until the rainforests collapsed in a cooling event at the transition from the Carboniferous to the Permian period.
A good part of the current rise in CO2 is due to the burning of the coal from the Carboniferous.
The CO2 levels in the Carboniferous were much higher than today, but there is one scenario in which CO2 levels could rise quickly and dramatically due to the release of methane from methane clathrate, mainly from ocean sediments and melting permafrost, as a consequence of ocean warming.
This methane is a potent greenhouse gas in its own right but is unstable and is oxidized to CO2 and water.
Today, there are no tropical lowlands anywhere near the extent of carboniferous coal swamps, and there are wood digesting organisms everywhere.
So even if the atmospheric CO2 levels go up dramatically, sequestration of organic carbon as wood would not have anywhere near the impact the mechanism had during the Carboniferous, as most wood would be oxidized by fire or biologic mechanisms, cycling the fixed carbon back into the atmosphere as CO2.
And here comes prochlorococcus, which is superabundant and is increasing its geographic range towards higher latitudes due to ocean warming.
Interestingly, prochlorococcus productivity is not constrained by limited availability of phosphate, as plants and phytoplanktons are, as it utilizes sulfolipids instead of phospholipids in its cell membranes.
I can't see a better candidate for large scale organic carbon sequestration than prochlorococcus proliferation driven organic carbon deposition in the increasingly anoxic ocean depths.
It is clear that the mechanisms outlined here act synergistically in part:
1. increasing CO2
2. ocean warming and spreading anoxia
3. prochlorococcus proliferation
4. methane release (? massive or not)
5. further increase in CO2 causing higher productivity in plants
6. further ocean warming and anoxia
7. sequestration of organic carbon from dead phytoplankton in the anoxic ocean depths with consequently rising atmospheric O2
8. possibly a new steady state with elevated O2, CO2 and terrestrial biomass and continual wildfires
This steady state could last for millions of years and would be eerily reminiscent of conditions in the Carboniferous minus the coal swamps.
Humans probably wouldn't do well in such a world.
Cheers!
World’s oceans changing colour due to climate breakdown, study suggests
The sea is becoming greener due to changes in plankton populations, analysis of Nasa images finds
Earth’s oceans are changing colour and climate breakdown is probably to blame, according to research.
The deep blue sea is actually becoming steadily greener over time, according to the study, with areas in the low latitudes near the equator especially affected.
“The reason we care about this is not because we care about the colour, but because the colour is a reflection of the changes in the state of the ecosystem,” said BB Cael, a scientist at the National Oceanography Centre at the University of Southampton and author of the study published in Nature.https://www.theguardian.com/environment/2023/jul/12/worlds-oceans-changing-colour-due-to-climate-breakdown-study-suggestsThe paper the article is referring to:
Global climate-change trends detected in indicators of ocean ecology
B. B. Cael, Kelsey Bisson, Emmanuel Boss, Stephanie Dutkiewicz & Stephanie Henson
Published: 12 July 2023, nature
https://www.nature.com/articles/s41586-023-06321-z
