Query: The grasslands, crops, forests and territorial waters of Australia absorb more carbon dioxide than Australia emits.

Relevant passages:
Carbon sink <=SEP=> A carbon sink is a natural or artificial reservoir that accumulates and stores some carbon-containing chemical compound for an indefinite period . The process by which carbon sinks remove carbon dioxide from the atmosphere is known as carbon sequestration . Public awareness of the significance of CO2 sinks has grown since passage of the Kyoto Protocol , which promotes their use as a form of carbon offset . There are also different strategies used to enhance this process .

Wetland <=SEP=> A wetland is a land area that is saturated with water , either permanently or seasonally , such that it takes on the characteristics of a distinct ecosystem . The primary factor that distinguishes wetlands from other land forms or water bodies is the characteristic vegetation of aquatic plants , adapted to the unique hydric soil . Wetlands play a number of roles in the environment , principally water purification , flood control , carbon sink and shoreline stability . Wetlands are also considered the most biologically diverse of all ecosystems , serving as home to a wide range of plant and animal life .   Wetlands occur naturally on every continent except Antarctica , the largest including the Amazon River basin , the West Siberian Plain , and the Pantanal in South America . The water found in wetlands can be freshwater , brackish , or saltwater . The main wetland types include swamps , marshes , bogs , and fens ; and sub-types include mangrove , carr , pocosin , and varzea .   The UN Millennium Ecosystem Assessment determined that environmental degradation is more prominent within wetland systems than any other ecosystem on Earth . International conservation efforts are being used in conjunction with the development of rapid assessment tools to inform people about wetland issues .   Constructed wetlands can be used to treat municipal and industrial wastewater as well as stormwater runoff . They may also play a role in water-sensitive urban design .

Carbon dioxide <=SEP=> Carbon dioxide ( chemical formula ) is a colorless gas with a density about 60 % higher than that of air ( 1.225 g/L ) that is odorless at normally encountered concentrations . Carbon dioxide consists of a carbon atom covalently double bonded to two oxygen atoms . It occurs naturally in Earth 's atmosphere as a trace gas at a concentration of about 0.04 percent ( 400 ppm ) by volume . Natural sources include volcanoes , hot springs and geysers , and it is freed from carbonate rocks by dissolution in water and acids . Because carbon dioxide is soluble in water , it occurs naturally in groundwater , rivers and lakes , ice caps , glaciers and seawater . It is present in deposits of petroleum and natural gas .   As the source of available carbon in the carbon cycle , atmospheric carbon dioxide is the primary carbon source for life on Earth and its concentration in Earth 's pre-industrial atmosphere since late in the Precambrian has been regulated by photosynthetic organisms and geological phenomena . Plants , algae and cyanobacteria use light energy to photosynthesize carbohydrate from carbon dioxide and water , with oxygen produced as a waste product .   Carbon dioxide is produced by all aerobic organisms when they metabolize carbohydrates and lipids to produce energy by respiration . It is returned to water via the gills of fish and to the air via the lungs of air-breathing land animals , including humans . Carbon dioxide is produced during the processes of decay of organic materials and the fermentation of sugars in bread , beer and winemaking . It is produced by combustion of wood and other organic materials and fossil fuels such as coal , peat , petroleum and natural gas .   It is a versatile industrial material , used , for example , as an inert gas in welding and fire extinguishers , as a pressurizing gas in air guns and oil recovery , as a chemical feedstock and in liquid form as a solvent in decaffeination of coffee and supercritical drying . It is added to drinking water and carbonated beverages including beer and sparkling wine to add effervescence . The frozen solid form of , known as `` dry ice '' is used as a refrigerant and as an abrasive in dry-ice blasting .   Carbon dioxide is the most significant long-lived greenhouse gas in Earth 's atmosphere . Since the Industrial Revolution anthropogenic emissions - primarily from use of fossil fuels and deforestation - have rapidly increased its concentration in the atmosphere , leading to global warming . Carbon dioxide also causes ocean acidification because it dissolves in water to form carbonic acid .

Reforestation <=SEP=> Reforestation is the natural or intentional restocking of existing forests and woodlands that have been depleted , usually through deforestation . Reforestation can be used to rectify or improve the quality of human life by soaking up pollution and dust from the air , rebuild natural habitats and ecosystems , mitigate global warming since forests facilitate biosequestration of atmospheric carbon dioxide , and harvest for resources , particularly timber , but also non-timber forest products .   The term reforestation is similar to afforestation , the process of restoring and recreating areas of woodlands or forests that may have existed long ago but were deforested or otherwise removed at some point in the past . Sometimes the term re-afforestation is used to distinguish between the original forest cover and the later re-growth of forest to an area . Forestation is the establishment of forest growth on areas that either had forest or lacked it .   Special tools , e.g. tree planting bars , are used to make planting of trees easier and faster .