Editing Coccolithophore (section)

===Impact on the carbon cycle===
Coccolithophores have both long and short term effects on the [[carbon cycle]]. The production of coccoliths requires the uptake of [[dissolved inorganic carbon]] and calcium. [[Calcium carbonate]] and [[carbon dioxide]] are produced from calcium and [[bicarbonate]] by the following chemical reaction:<ref name=Mejia2011>{{citation |journal=PLOS Biology  |volume=9 |issue=6 |year=2011 |pages=e1001087 |title=Will Ion Channels Help Coccolithophores Adapt to Ocean Acidification? |first=R. |last=Mejia |doi=10.1371/journal.pbio.1001087|pmid=21713029 |pmc=3119655 |doi-access=free }}</ref>
: {{chem2|Ca(2+) + 2HCO3− <-> CaCO3 + CO2 + H2O}}

Because coccolithophores are photosynthetic organisms, they are able to use some of the {{CO2}} released in the calcification reaction for [[photosynthesis]].<ref name=Mackinder2010>{{citation |journal=Geomicrobiology Journal |volume=27 |issue=6–7 |year=2010 |pages=585–595 |title=Molecular Mechanisms Underlying Calcification in Coccolithophores |last1=Mackinder |doi=10.1080/01490451003703014|last2=Wheeler |first2=Glen |last3=Schroeder |first3=Declan |last4=Riebesell |first4=Ulf |last5=Brownlee |first5=Colin |bibcode=2010GmbJ...27..585M |s2cid=85403507 |display-authors=etal}}</ref>

However, the production of calcium carbonate drives surface alkalinity down, and in conditions of low alkalinity the {{CO2}} is instead released back into the atmosphere.<ref name=Bates1996>{{citation |journal=Marine Chemistry |volume=51 |issue=4 |year=1996 |pages=347–358 |title=Alkalinity changes in the Sargasso Sea; geochemical evidence of calfication? |last1=Bates |doi=10.1016/0304-4203(95)00068-2|last2=Michaels |first2=Anthony F. |last3=Knap |first3=Anthony H. |bibcode=1996MarCh..51..347B |display-authors=etal}}</ref>
As a result of this, researchers have postulated that large blooms of coccolithophores may contribute to global warming in the short term.<ref name=Marsh2003>{{citation |journal=Comparative Biochemistry and Physiology B |volume=136 |issue=4 |year=2003 |pages=743–754 |title=Regulation of CaCO3 formation in coccolithophores |first=M.E. |last=Marsh |doi=10.1016/s1096-4959(03)00180-5|pmid=14662299 }}</ref> A more widely accepted idea, however, is that over the long term coccolithophores contribute to an overall decrease in atmospheric {{CO2}} concentrations.  During calcification two carbon atoms are taken up and one of them becomes trapped as calcium carbonate.  This calcium carbonate sinks to the bottom of the ocean in the form of coccoliths and becomes part of sediment; thus, coccolithophores provide a sink for emitted carbon, mediating the effects of greenhouse gas emissions.<ref name=Marsh2003 />