Explain Carbon sequestration.

Carbon sequestration is the process by which carbon dioxide (CO2) is removed from the atmosphere and stored in carbon sinks such as forests, soils, oceans, and geological formations. It plays a crucial role in mitigating climate change by reducing the concentration of greenhouse gases in the atmosphere, thereby helping to counteract global warming and its associated impacts.

Natural carbon sequestration occurs through various biological, chemical, and physical processes:

1. Terrestrial Sequestration: Forests, grasslands, and other terrestrial ecosystems act as carbon sinks, absorbing CO2 from the atmosphere through photosynthesis. Trees and plants use CO2, water, and sunlight to produce carbohydrates and oxygen, storing carbon in their biomass and soils. Soil organic matter also stores significant amounts of carbon through decomposition of plant and organic residues. Sustainable land management practices such as afforestation, reforestation, agroforestry, and soil conservation enhance terrestrial carbon sequestration.

2. Oceanic Sequestration: The world's oceans absorb CO2 from the atmosphere through a process known as oceanic carbon uptake. CO2 dissolves in seawater, forming carbonic acid and carbonate ions, which are then utilized by marine organisms such as phytoplankton, algae, and corals for photosynthesis and shell formation. The deep ocean also acts as a long-term carbon sink, storing dissolved CO2 and organic carbon in marine sediments.

3. Geological Sequestration: Carbon dioxide can be captured from industrial sources such as power plants and factories and stored underground in geological formations such as depleted oil and gas reservoirs, saline aquifers, and deep geological formations. This process, known as carbon capture and storage (CCS), prevents CO2 emissions from entering the atmosphere and sequesters carbon in stable geological reservoirs over long time scales.

Carbon sequestration helps to mitigate climate change by reducing the concentration of CO2 in the atmosphere, thereby slowing the rate of global warming and its associated impacts such as rising temperatures, sea-level rise, and extreme weather events. However, it is important to note that carbon sequestration is not a substitute for reducing greenhouse gas emissions at their source. Efforts to decarbonize energy systems, transition to renewable energy sources, and promote sustainable land management practices are essential for achieving long-term climate goals and ensuring a stable and resilient future.