Global climate change

Marine Snow and Atmospheric CO2

4/19/2010, 7:51:26 AM
Phytoplankton blooms (bright, light blue) off the Grand banks of Newfoundland. The thin, straight cloud lines might be trans-Atlantic aircraft contrails.

"Marine snow", is actually the shells and excretions of phytoplankton that sink down from the ocean surface.

Ocean creatures below the ocean surface consume the "snow", which then recycle up to 90% of the carbon back into the water as carbon dioxide (CO2).

Most of the recycling happens in the first 689 feet (210 meters) below the ocean surface, according to the Discovery News article

But, according to a new study published in the journal Nature Geoscience, if that depth sank just another 79 feet or 24 meters, it would be able to remove up to 27 PPM more CO2 from the atmosphere.

"That's not very big -- natural variability of that depth is several hundred meters," according to Ken Buesseler of the Woods Hole Oceanographic Institute, who was not involved with the study.

The reason why a slight change in depth would reduce atmospheric CO2 is that the deeper the snow falls into the ocean without being eaten, the more carbon-rich snow reaches the ocean floor. Once it is eaten, it becomes dissolved CO2, and it's just a matter of a short time (months to years instead of tens of thousands of years for the snow) before it makes its way back into the atmosphere.

But, many scientists predict that ocean warming will raise the depth at which most carbon cycles back into the water. If that happens, the seas will hasten global warming as they spew CO2 back out into the air.

The views expressed are those of the author and not necessarily those of AccuWeather, Inc. or


Comments that don't add to the conversation may be automatically or manually removed by Facebook or AccuWeather. Profanity, personal attacks, and spam will not be tolerated.

Global climate change