Massive amounts of charcoal enter the world’s oceans, with an estimated 25 million tons of dissolved charcoal being transported from land to the sea each year[1]. This charcoal dissolution is important for calculating the global carbon budget, which is a balancing act between sources that produce carbon and sinks that remove it[1].
When charcoal forms, it is typically deposited in the soil, and it was previously believed that it did not dissolve[2]. However, recent findings show that charcoal does dissolve, and this dissolution has implications for the global carbon cycle[2].
Ocean acidification is another significant consequence of excess carbon dioxide in the atmosphere, as at least one-quarter of the carbon dioxide released by burning coal, oil, and gas dissolves into the ocean[5]. Since the beginning of the industrial era, the ocean has absorbed around 525 billion tons of CO2 from the atmosphere, which is presently around 22 million tons per day[5]. Although this absorption has slowed global warming, it has come at the cost of changing the ocean’s chemistry, making the water more acidic and affecting the pH levels[5]. This acidification can have negative impacts on marine life, particularly for organisms that rely on carbonate ions to build shells and skeletons[5].
Citations:
[1] https://www.sciencedaily.com/releases/2013/04/130419160715.htm
[2] https://www.mpg.de/7112434/charcoal_oceans
[3] https://physicsworld.com/a/oceans-could-have-reached-carbon-threshold/
[4] https://www.whoi.edu/know-your-ocean/ocean-topics/how-the-ocean-works/ocean-chemistry/ocean-acidification/
[5] https://ocean.si.edu/ocean-life/invertebrates/ocean-acidification
[6] https://www.eurekalert.org/pub_releases/2013-04/m-mao041913.php
Since charcoal is presumably missing electrons and is therefore a free radical, it should absorb pollutants like in your water filter?
It could however cause various cancers in aquatic life forms if not already anti-oxidised.