The link from the IPCC has a diagram of the carbon cycle. Since carbon is the result of plants reducing carbon dioxide to carbon and oxygen, and the plants must release oxygen to capture the carbon, its a good proxy for the oxygen cycle. For every ton of carbon captured the plants must release 2.7 tons of oxygen. However there are a few wrinkles.
The IPCC's diagram shows 120 Gigatons (that is 120 billion metric tons) of carbon absorbed each year by land plants and 103 Gigatons by ocean plants such as phytoplankton and algae. This would correspond to 320 Gigatons or 53.8 % of oxygen released by land based plants and 275 Gigatons or 46.2% oxygen released by marine plants.
However the diagram is quite complex and shows transfers of carbon to the deep ocean and some immediate use of oxygen produced. The ocean according to the IPCC is a small net producer of oxygen and a small net sink for carbon dioxide, offsetting the larger net absorption of oxygen and production of carbon dioxide by the land (including human activities).
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The link from the IPCC has a diagram of the carbon cycle. Since carbon is the result of plants reducing carbon dioxide to carbon and oxygen, and the plants must release oxygen to capture the carbon, its a good proxy for the oxygen cycle. For every ton of carbon captured the plants must release 2.7 tons of oxygen. However there are a few wrinkles.
The IPCC's diagram shows 120 Gigatons (that is 120 billion metric tons) of carbon absorbed each year by land plants and 103 Gigatons by ocean plants such as phytoplankton and algae. This would correspond to 320 Gigatons or 53.8 % of oxygen released by land based plants and 275 Gigatons or 46.2% oxygen released by marine plants.
However the diagram is quite complex and shows transfers of carbon to the deep ocean and some immediate use of oxygen produced. The ocean according to the IPCC is a small net producer of oxygen and a small net sink for carbon dioxide, offsetting the larger net absorption of oxygen and production of carbon dioxide by the land (including human activities).