Ocean Acidification and the End-Permian Mass Extinction: To What Extent does Evidence Support Hypothesis?

Geosciences

Stephen Kershaw³  Sylvie Crasquin⁴  Yue Li²  Pierre-Yves Collin¹ 

[1] UMR5561 Biogéosciences, Bâtiment Gabriel, Université de Bourgogne, Dijon 21000, France;Nanjing Institute of Geology and Palaeontology, Nanjing 210008, China;;Institute for the Environment, Halsbury Building, Brunel University, Uxbridge UB8 3PH, UKCNRS-UMR7207, CR2P ‘Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements’, Université Pierre et Marie Curie-Paris 6, Paris 75252 Cedex 05 , France;

关键词: ocean acidification;    end-Permian extinction;    microbialite;    ocean buffer;    stylolite;   

DOI  :  10.3390/geosciences2040221

来源: mdpi

【 摘 要 】

Ocean acidification in modern oceans is linked to rapid increase in atmospheric CO₂, raising concern about marine diversity, food security and ecosystem services. Proxy evidence for acidification during past crises may help predict future change, but three issues limit confidence of comparisons between modern and ancient ocean acidification, illustrated from the end-Permian extinction, 252 million years ago: (1) problems with evidence for ocean acidification preserved in sedimentary rocks, where proposed marine dissolution surfaces may be subaerial. Sedimentary evidence that the extinction was partly due to ocean acidification is therefore inconclusive; (2) Fossils of marine animals potentially affected by ocean acidification are imperfect records of past conditions; selective extinction of hypercalcifying organisms is uncertain evidence for acidification; (3) The current high rates of acidification may not reflect past rates, which cannot be measured directly, and whose temporal resolution decreases in older rocks. Thus large increases in CO₂ in the past may have occurred over a long enough time to have allowed assimilation into the oceans, and acidification may not have stressed ocean biota to the present extent. Although we acknowledge the very likely occurrence of past ocean acidification, obtaining support presents a continuing challenge for the Earth science community.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.