Warmer Seas Blocking Nature’s Carbon Pump
Diatoms are one of the most common types of phytoplankton.
Climate change isn’t just warming the atmosphere, it’s also warming the ocean’s surface and deeper levels of the water column. This is known as the pelagic ocean (the “pelagic zone” is any part of the water column other than that at the sea floor) and it just so happens to harbor the most productive ecosystem on planet Earth. The pelagic ocean is responsible for an estimated half of the world’s primary production (i.e., the basic food or nutrient making needed to sustain other life), and sustains most of the world’s natural fisheries.
The pelagic zone also plays a very complex but important role in the global carbon cycle. Inorganic carbon (mostly in the form of CO2) can be “drawn down” from the atmosphere by two main processes: the respiration of photo-synthetic algae and plankton (which produce oxygen and serve as a food source as well), and, secondly, the sedimentation of carbon (in the form of sinking, dead marine matter) onto the sea floor. Most algae and phytoplankton have chlorophyll and live in the upper most layer of the water column where there is sufficient sunlight penetration (this is called the euphotic zone; from the surface down to 200 meters is the epipelagic zone). Although carbon is also removed via “outgassing” (the exporting of carbon and carbon-based molecules into the atmosphere via ocean-air circulation), these two processes keep carbon out of the atmosphere. And of the two, bottom accumulation (via sinking) is the predominant means by which carbon is removed from the water column.
This entry was posted on Saturday, October 31st, 2009 at 9:23 pm and is filed under Environment, Global Warming, efficiency, energy conservation, green, green building. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.