One way or another the oceans are key to the capture, transmutation and storage of .*
From Works in Progress, May 23, 2023:
Olivine is a green mineral that reacts with CO2 in the ocean to form a harmless silt. This reaction might be the key to slowing down climate change, or reversing it altogether.
A long cycle – as powerful as it is slow – is at work in the rocks, rainwater and air of Earth. Over eons, it moderates the planet’s temperature, makes molehills of mountains, and smooths out fluctuations in the climate.
Consider the lowly carbon dioxide molecule. When released into the atmosphere from fossil fuel combustion or a volcanic eruption, a molecule of CO₂ will only stay in the air for four to five years on average. By that point, it is more likely than not to have become part of a plant via photosynthesis, or have dissolved into rainwater and flushed into the ocean. When the tree it was incorporated into decomposes, or it roils up to the surface of the sea on the crest of a wave, it enters the atmosphere again, ad infinitum.
But there’s a catch to this process: weathering. Dissolved CO₂, in the form of carbonic acid (H₂CO₃), makes rainwater slightly acidic – even in preindustrial times, the pH of rainwater was well below six – and acids react with the rocks that comprise the Earth’s surface. Most of our planet’s crust (about 90 percent) is composed of silicates, minerals formed by bonding metal atoms to one of a number of combinations of silicon and oxygen.
When rainfall hits a silicate molecule, the metal reacts with the dissolved carbonic acid to form a carbonate mineral (containing the carbonate ion CO₃⁻² or the closely related bicarbonate, H₂CO₃), abandoning the silicate ion to an independent existence as silicon dioxide (SiO₂) – plain beach sand. Since both the carbonate and the sand usually end up flowing down into the ocean with the rainwater that birthed them, the reaction of dissolved CO₂ with minerals is one of the primary forces that files jagged Himalayas and Andes down into soft, rounded Appalachians and Ozarks.
As is often the case in chemistry, other factors come into play. More acidic rainwater and warmer temperatures cause the weathering reaction to proceed faster than it otherwise would. The result, over a time period of thousands to millions of years, is that atmospheric CO₂ levels are self-correcting: when they rise (usually due to geological activity), the rate of weathering speeds up, which sequesters the excess carbon faster....
....MUCH MORE
*If interested see:
February 2021
"Searching for the Dust That Cooled the Planet"
This is why you want to be careful with the geoengineering proposals. Some links after the jump....
*****
....One of the reasons we ran Plankton Week last October—no, not as counterprogramming to Shark Week—was to refresh memories of one of the topics of conversation at all the better salons and soirées circa 2007.
Plankton Week: “Give me a half tanker of iron, and I will give you an ice age.”
The headline quote is from oceanographer John Martin during a 1988 lecture at Woods Hole Oceanographic Institution. Here's NASA's Earth Observatory archive page on the statement.
It is a bit of an exaggeration, you may need ten of those Valemax bulk carriers, currently the second largest ships in the world at 400,000 dwt (Euronav's two TI oil tankers at 441,000 dwt are bigger), to make an environmental change but what a change it would be. The orders of magnitude of carbon the iron-fed plankton would sequester are almost mind-boggling:
...Martin gathered the results of the incubation experiments and laid out the evidence in support of the Iron Hypothesis together with some back‐of‐the‐envelope calculations and presented his findings at a Journal Club lecture at Woods Hole Oceanographic Institution in July of 1988. He estimated that using a conservative Fe : C ratio that 300,000 tons of iron in the Southern Ocean induce the growth of phytoplankton that could draw down an estimated two billion tons of carbon dioxide. Then, putting on his best Dr. Strangelove accent, he suggested that “with half a ship load of iron….I could give you an ice age.” The symposium broke up with laughter and everyone retired to the lawn outside the Redfield Building for beers (from Chisholm and Morel, Editors, preface to: What controls phytoplankton production in nutrient‐rich areas of the open sea? Limnology and Oceanography, 36, 8 December 1991).
As repeated in "John Holland Martin: From Picograms to Petagrams and Copepods to Climate"
—Bulletin of Limnology and Oceanography, Wiley. 25 March 2016
....Coming up tomorrow, the Pope, and a Vancouver stock promoter.
Our series thus far:
October 27
Plankton Week: "Metal deposits from Chinese coal plants end up in the Pacific Ocean, research shows"
October 26
"Plankton Bloom Heralded Earth’s Greatest Extinction"
