A carbon sink is a natural or man-made reservoir that absorbs and stores carbon dioxide (CO2) from the atmosphere. This process helps to mitigate climate change by reducing the amount of greenhouse gases in the air, as CO2 is one of the primary contributors to global warming. Carbon sinks can be found in various forms such as forests, oceans, and soil, which absorb CO2 through photosynthesis or chemical reactions with water. Human activities like afforestation, reforestation, and conservation agriculture also create artificial carbon sinks by increasing the capacity of natural systems to store carbon.