title: Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms.
abstract: Today's surface ocean is saturated with respect to calcium carbonate, but increasing atmospheric carbon dioxide concentrations are reducing ocean pH and carbonate ion concentrations, and thus the level of calcium carbonate saturation. Experimental evidence suggests that if these trends continue, key marine organisms--such as corals and some plankton--will have difficulty maintaining their external calcium carbonate skeletons. Here we use 13 models of the ocean-carbon cycle to assess calcium carbonate saturation under the IS92a 'business-as-usual' scenario for future emissions of anthropogenic carbon dioxide. In our projections, Southern Ocean surface waters will begin to become undersaturated with respect to aragonite, a metastable form of calcium carbonate, by the year 2050. By 2100, this undersaturation could extend throughout the entire Southern Ocean and into the subarctic Pacific Ocean. When live pteropods were exposed to our predicted level of undersaturation during a two-day shipboard experiment, their aragonite shells showed notable dissolution. Our findings indicate that conditions detrimental to high-latitude ecosystems could develop within decades, not centuries as suggested previously.
authors.affiliation: Laboratoire des Sciences du Climat et de l'Environnement, UMR CEA-CNRS, CEA Saclay, F-91191 Gif-sur-Yvette, France. orr@cea.fr
authors.forename: James C
authors.initials: JC
authors.lastname: Orr
authors.forename: Victoria J
authors.initials: VJ
authors.lastname: Fabry
authors.forename: Olivier
authors.initials: O
authors.lastname: Aumont
authors.forename: Laurent
authors.initials: L
authors.lastname: Bopp
authors.forename: Scott C
authors.initials: SC
authors.lastname: Doney
authors.forename: Richard A
authors.initials: RA
authors.lastname: Feely
authors.forename: Anand
authors.initials: A
authors.lastname: Gnanadesikan
authors.forename: Nicolas
authors.initials: N
authors.lastname: Gruber
authors.forename: Akio
authors.initials: A
authors.lastname: Ishida
authors.forename: Fortunat
authors.initials: F
authors.lastname: Joos
authors.forename: Robert M
authors.initials: RM
authors.lastname: Key
authors.forename: Keith
authors.initials: K
authors.lastname: Lindsay
authors.forename: Ernst
authors.initials: E
authors.lastname: Maier-Reimer
authors.forename: Richard
authors.initials: R
authors.lastname: Matear
authors.forename: Patrick
authors.initials: P
authors.lastname: Monfray
authors.forename: Anne
authors.initials: A
authors.lastname: Mouchet
authors.forename: Raymond G
authors.initials: RG
authors.lastname: Najjar
authors.forename: Gian-Kasper
authors.initials: GK
authors.lastname: Plattner
authors.forename: Keith B
authors.initials: KB
authors.lastname: Rodgers
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Sabine
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Sarmiento
authors.forename: Reiner
authors.initials: R
authors.lastname: Schlitzer
authors.forename: Richard D
authors.initials: RD
authors.lastname: Slater
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Totterdell
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Weirig
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yamanaka
authors.forename: Andrew
authors.initials: A
authors.lastname: Yool
mesh_terms: D000143:Acids / Q000032:analysis; D000818:Animals; D037421:Anthozoa / Q000378:metabolism; D001272:Atmosphere / Q000737:chemistry; D002113:Calcification, Physiologic; D002119:Calcium Carbonate / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D002980:Climate; D017753:Ecosystem; D020387:Food Chain; D006863:Hydrogen-Ion Concentration; D009792:Oceans and Seas; D010933:Plankton / Q000737:chemistry / Q000378:metabolism; D012623:Seawater / Q000737:chemistry*; D013816:Thermodynamics; D013997:Time Factors; D035501:Uncertainty
chemical_list: D000143:Acids; D002245:Carbon Dioxide; D002244:Carbon; D002119:Calcium Carbonate