Carbon sequestration

The method of trapping and conserving atmospheric carbon dioxide is known as carbon sequestration. Long-term carbon storage in plants, soils, geologic formations, and the ocean is referred to as carbon sequestration. Carbon sequestration is the storage of carbon that has the imminent potential to produce carbon dioxide gas, and it occurs both naturally and as a result of anthropogenic actions. It is one approach to lowering carbon dioxide levels in the atmosphere with the purpose of decreasing global warming. In response to rising concerns about climate change caused by rising carbon dioxide levels in the atmosphere, researchers have been looking into the possibility of increasing carbon sequestration rates through changes in land use and forestry, as well as geoengineering techniques like carbon capture and storage. 

Human activities like burning fossil fuels have released carbon from long-term geologic storage as coal, petroleum, and natural gas and transferred it to the atmosphere as carbon dioxide gas. Carbon dioxide is also emitted naturally as plants and animals decompose. Since the beginning of the industrial period, the amount of carbon dioxide in the atmosphere has risen, owing primarily to the burning of fossil fuels. Carbon dioxide is a particularly efficient greenhouse gas, absorbing infrared heat emitted from the Earth's surface. More infrared radiation is retained when carbon dioxide concentrations grow in the atmosphere, raising the average temperature of Earth's lower atmosphere. Global warming is the name given to this phenomenon.

Carbon sinks are reservoirs that store carbon and prevent it from entering the atmosphere. Deforestation, for example, emits carbon into the atmosphere, whereas forest regeneration is a type of carbon sequestration, with the forests themselves acting as carbon sinks. Through photosynthesis, carbon is naturally transported from the atmosphere to terrestrial carbon sinks, where it may be stored in both aboveground biomass and soils. Other terrestrial processes that store carbon include the growing of replacement vegetation on cleared land, carbon-absorbing land-management techniques, and accelerated growth due to decrease atmospheric carbon dioxide levels and increase nitrogen deposition. 

The terrestrial sink has the potential to add enormous amounts of carbon to the atmosphere and oceans if it becomes a significant carbon source through increasing combustion and decomposition. The total quantity of carbon in plants, soil, and detritus on the planet is around 2,200 gigatons, and the amount of carbon sequestered yearly by terrestrial ecosystems is estimated to be around 2.6 gigatons. Carbon is also accumulated in the oceans, with around 920 gigatons found just beneath the surface. The quantity of carbon stored in the oceanic sink is greater than that which is present in the atmosphere. Only 45 percent of carbon released into the atmosphere by human activities remains in the atmosphere; around 30 percent is taken up by the oceans, and the rest is absorbed by terrestrial ecosystems.

• Mechanisms of Carbon Sequestration:

1. Photosynthesis: One of nature's most remarkable carbon sequestration processes occurs through photosynthesis, wherein plants, algae, and certain bacteria convert atmospheric CO2 into organic carbon compounds. Trees and other vegetation play a critical role in this process by absorbing CO2 during photosynthesis and storing it as carbon in their biomass.
2. Ocean Sequestration: The world's oceans act as vast carbon sinks, absorbing CO2 from the atmosphere. Phytoplankton, marine plants, also play a role in carbon sequestration through photosynthesis. Additionally, when ocean-dwelling organisms die, their organic matter sinks to the ocean floor, trapping carbon in sediments.
3. Soil Carbon Storage: Carbon is stored in soils through the decomposition of organic matter by microorganisms. Practices such as afforestation, reforestation, and sustainable agricultural practices can enhance soil carbon storage.
4. Geological Sequestration: Certain geological formations, such as depleted oil and gas reservoirs and deep saline aquifers, can serve as long-term carbon storage sites. This process involves capturing CO2 from industrial sources and injecting it into underground formations.

• Importance of Human-Driven Carbon Sequestration Strategies:

Human activities significantly impact the carbon cycle, leading to increased greenhouse gas emissions. To address this, several human-driven strategies are being pursued to enhance carbon sequestration:

1. Afforestation and Reforestation: Planting trees and restoring degraded forests help increase carbon uptake and storage, enhancing natural carbon sequestration.
2. Sustainable Land Management: Implementing sustainable land-use practices, such as agroforestry and conservation agriculture, can promote soil carbon storage and reduce carbon emissions.
3. Carbon Capture and Storage (CCS): CCS technologies capture CO2 emissions from industrial processes and power plants, preventing them from entering the atmosphere, and store the CO2 underground.
4. Blue Carbon Initiatives: Protecting and restoring coastal ecosystems like mangroves, seagrasses, and salt marshes, known as blue carbon ecosystems, enhances carbon sequestration.

Improved farming practices and forest-related mitigation efforts can help remove carbon dioxide from the atmosphere at a low cost. Improved agricultural and grazing land management, such as more effective fertilizer usage to limit the leaching of unneeded nitrates, tillage methods that reduce soil erosion, the restoration of organic soils, and the rehabilitation of degraded lands, are examples of these activities. Furthermore, existing forests, particularly rainforests in the Amazon and elsewhere, must be preserved in order for carbon to continue to be sequestered in those crucial terrestrial sinks.