Forests are natural carbon sinks and so are oceans and soils. A 'carbon sink' is a system that can absorb more carbon than it emits.
Can natural carbon sinks be helped? According to much research, yes, through CO2 capture using artificial systems. These methods are very expensive because the concentration of CO2 in the atmosphere is low: just over 400 PPM or Parts Per Million: if you divide a volume of air into one million bubbles, 400 of these are CO2. But if capturing it from the air is costly, MIT – Massachusetts Institute of Technology – has announced a new method: capturing CO2 from oceans instead of the air. Why is that? One of the main reasons for this is that "in oceans, the capturing stage has already been done for us," say the MIT researchers. This is because oceans absorb 30 to 40 per cent of greenhouse gases from the atmosphere, concentrating them in densities more than 100 times higher than that of air. Devices to capture gases from the ocean could be mounted on large merchant ships so that as they sail the 7 seas they could 'clean up' the waters.
