Microphoto of coccolithophore courtesy of Discover

Global Warming: it's all about PLANKTON What you won't hear on the News of the Powerful and Rich: At the base of the planet's food pyramid is phytoplankton, producing half of the free oxygen on the planet by photosynthesis. Largely, they constitute three groups: coccolithophorids, diatoms, and dinoflagellates inhabiting the ocean's photic zone. The marine coccolithophores, which surprisingly grow best more than 30 meters below the sunlit surface, are among the ocean's most abundant plankton. They make calcite (CaCO3) shells (coccoliths) by biomineralization that constitute the world's most significant sink of the greenhouse gas carbon dioxide.

They are in decline due to warming oceanic temperatures. Our gas-guzzling habits are pushing the lever of a collosal global switch we will not be able to reverse once it clicks. Multiple positive feedbacks, each possibly catastrophic acting alone, are all working in the same direction:

• Increased oceanic heat causes thermal stratification, making fewer nutrients mixed into the photic zone
• Increased atmospheric carbon dioxide dissolving into the ocean lowers the pH, reducing production of calcium carbonate
• Metabolism increases more greatly with temperature than does photosynthesis
• Temperature reduces the oxygen content of water
• Fewer coccoliths reduces the earth's albedo
• Higher temperatures and fewer plankton reduce cloud formation which reduces the earth's albedo
• Fewer plankton reduces the biomass of the entire food chain, resulting in fewer nutrients dropped back into the ocean

Angel L—pez-Urrutia: Vast areas of the North East Atlantic have already become a carbon source, with respiration of the plankton community almost 150 percent of photosynthesis.

Photosynthesis should increase as atmospheric levels of carbon dioxide rise, increasing productivity and converting some of the excess carbon dioxide into biomass. However, the actual increase is lower than you would expect.

A 9-year study released in the December 7, 2006 journal Nature by Dave Siegel, professor of marine science at UC Santa Barbara and others show that the growth rate and abundance of phytoplankton decreases in warm ocean years and increases in cooler ones, by using NASA satellite data to measure the oceans' color to determine the amount of phytoplankton and the growth rates. "We can know the amount of plants in the ocean by looking at the ocean's color. A blue ocean has no phytoplankton in it. The beautiful tropical oceans that you see on postcards have little in it. The green ocean is chock-full of phytoplankton.''

An observed positive corelation of phytoplankton and cloud formation is attributed to cloud condensation nuclei (CCN). Secondary organic aerosol (SOA), formed from the oxidation of phytoplankton-produced isoprene, may affect chemical composition of marine CCN and increase cloud droplet number.

Because they contain calcium carbonate (chalk) coccolithophore blooms increase the amount of light reflected off the planet, helping to cool it.

Not only do phytoplankton form the base of the oceans' food chain, they also produce at least 80% of the oxygen that we breathe. (Note: the production of oxygen by phytoplankton is an estimate, and you can find figures ranging from less than 50% to over 90% in the literature)

Ocean acidification is caused by uptake of anthropogenic carbon dioxide from the atmosphere. Between 1751 and 2004 surface ocean pH is estimated to have dropped from approximately 8.25 to 8.14.

White pox disease killing 95% of elkhorn coral near Key West, Florida (mortality also in the U.S. Virgin Islands, Caribbean areas of Mexico, and the Bahamas), was traced to Serrate marcescens, a human intestinal bacterium, according to James W. Porter.

One result of the disruption of coral reef ecology is blooms of the starfish from hell(.pdf), the crown of thorns starfish, (Acanthaster planci), growing to over a meter in diameter, with up to 21 arms. They are covered with 3cm toxic spines, a puncture wound from which causes pain, edema, nausea and vomiting. They can move up to 20m per hour, and have the highest fertilization rate for any invertebrate, a female producing some one billion eggs in her lifetime.

No pear-shaped eggs, no downy chicks, no next generation of guillemots.