Carbon sequestration
[7] The IPCC Special Report on the Ocean and Cryosphere in a Changing Climate recommends "further research attention" on seaweed farming as a mitigation tactic.
[9]: 2248 Subsequently, a pool is defined as "a reservoir in the Earth system where elements, such as carbon and nitrogen, reside in various chemical forms for a period of time".
[citation needed] The IPCC, however, defines CCS as "a process in which a relatively pure stream of carbon dioxide (CO2) from industrial sources is separated, treated and transported to a long-term storage location".
[citation needed] Carbon dioxide is naturally captured from the atmosphere through biological, chemical, or physical processes, and stored in long-term reservoirs.
Events such as wildfires or disease, economic pressures, and changing political priorities can result in the sequestered carbon being released back into the atmosphere.
It helps to slow the atmospheric and marine accumulation of greenhouse gases, which is mainly carbon dioxide released by burning fossil fuels.
These include the conservation, management, and restoration of ecosystems such as forests, peatlands, wetlands, and grasslands, in addition to carbon sequestration methods in agriculture.
Earth offers enough room to plant an additional 0.9 billion ha of tree canopy cover, although this estimate has been criticized,[38][39] and the true area that has a net cooling effect on the climate when accounting for biophysical feedbacks like albedo is 20-80% lower.
Simon Lewis stated, "Tropical forest trees are absorbing about 18% of the carbon dioxide added to the atmosphere each year from burning fossil fuels, substantially buffering the rate of change.
[61][62] Aside from climate benefits, wetland restoration and conservation can help preserve biodiversity, improve water quality, and aid with flood control.
The waterlogged nature of the soil slows down the decomposition of organic material, leading to the accumulation of carbon-rich sediments,[clarification needed] acting as a long-term carbon sink.
[64][65] Also, anaerobic conditions in waterlogged soils hinder the complete breakdown of organic matter, promoting the conversion of carbon into more stable forms.
[69] Not only are wetlands a great carbon sink, they have many other benefits like collecting floodwater, filtering out air and water pollutants, and creating a home for numerous birds, fish, insects, and plants.
[72][73] Most peatlands are situated in high latitude areas of the northern hemisphere, with most of their growth occurring since the last ice age,[74] but they are also found in tropical regions, such as the Amazon and Congo Basin.
[75] Peatlands grow steadily over thousands of years, accumulating dead plant material – and the carbon contained within it – due to waterlogged conditions which greatly slow rates of decay.
[71] Peatland protection and restoration are therefore important measures to mitigate carbon emissions, and also provides benefits for biodiversity,[76] freshwater provision, and flood risk reduction.
Agricultural methods for carbon farming include adjusting how tillage and livestock grazing is done, using organic mulch or compost, working with biochar and terra preta, and changing the crop types.
[96][97] Adding biochar may increase the soil-C stock for the long term and so mitigate global warming by offsetting the atmospheric C (up to 9.5 Gigatons C annually).
[105] Geological sequestration refers to the storage of CO2 underground in depleted oil and gas reservoirs, saline formations, or deep, coal beds unsuitable for mining.
Carbonic acid in groundwater slowly reacts with complex silicates to dissolve calcium, magnesium, alkalis and silica and leave a residue of clay minerals.
Rocks rich in metal oxides that react with CO2, such as MgO and CaO as contained in basalts, have been proven as a viable means to achieve carbon-dioxide mineral storage.
Alternatively, the mineral could be milled to increase its surface area, and exposed to water and constant abrasion to remove the inert silica as could be achieved naturally by dumping olivine in the high energy surf of beaches.
[citation needed] The low temperatures, high pressure, and reduced oxygen levels in the deep sea slow down decomposition processes, preventing the rapid release of carbon back into the atmosphere and acting as a long-term storage reservoir.
[6] Wild seaweed will sequester large amount of carbon through dissolved particles of organic matter being transported to deep ocean seafloors where it will become buried and remain for long periods of time.
[7] The IPCC Special Report on the Ocean and Cryosphere in a Changing Climate recommends "further research attention" on seaweed farming as a mitigation tactic.
Peter Fiekowsky and Carole Douglis write "I consider iron fertilization an important item on our list of pottential climate restoration solutions.
Given the fact that iron fertilization is a natural process that has taken place on a massive scale for millions of years, it is likely that most of the side effects are familiar ones that pose no major threat" [144] Artificial upwelling or downwelling is an approach that would change the mixing layers of the ocean.
[156] Underwater basalt offers a good alternative to other forms of oceanic carbon storage because it has a number of trapping measures to ensure added protection against leakage.
[160] Researchers have demonstrated that the carbon dioxide marine storage at several kilometers depth could be viable for up to 500 years, but is dependent on injection site and conditions.
[178] The most recent IPCC Sixth Assessment Report in 2022 also no longer includes any mention of "ocean storage" in its "Carbon Dioxide Removal taxonomy".
