The oceans are a huge reservoir for CO₂,containing 50 times more than the atmosphere and 20 times more than the biosphere,furthermore,they play an important role in regulating the levels of atmospheric CO₂,and hence global climate.The CO₂ between the oceans and the atmosphere is out of equilibrium ,the equatorial Pacific and Atlantic oceans are supersaturated with CO₂ and hence are strong CO₂ source areas,on the other hand,the Southern and the North Atlantic oceans are strong sinks of atmospheric CO₂.The oceans have taken up large amounts of anthropogenic CO₂,models of global carbon cycle yield a mean oceanic CO₂ uptake of 2.0 Gt C/a.The oceans' capacity to take up CO₂ depends laregely on the effect of the biological pump and the dynamics of ocean circulation.Future concentration of atmospheric CO₂ is hard to predict because of our incomplete understanding of how the oceans would respond to the global warming.To improve our ability to estimate future CO₂ concentration,intense further research on oceanic CO₂ is necessary.