Science News Everyday 08.06.18

Acid Tests

A somewhat neglected but extremely important consequence of the ongoing anthropogenic rise in the concentration of atmospheric carbon dioxide is that the ocean is becoming more acidic as it absorbs more of the gas. This acidification is making seawater more corrosive toward calcium carbonate, the material used by many marine organisms to make their exoskeletons.Feelyet al.(p.1490, published online 22 May) report results from 13 hydrographic transects from southernCanadato northernMexico. Potentially corrosive seawater upwelled onto large portions of the continental shelf in 2007. Such seasonal upwelling of such waters onto the shelf is a natural phenomenon, but the ocean uptake of anthropogenic CO₂has exposed increasing portions of the shelf to potentially damaging effects.

大气中二氧化碳浓度的持续人为增长具有某种负面的、且相当重要的影响，即令海水吸收了过多的气体，导致酸度上升。这种酸化效应使得海水对碳酸钙更加具有腐蚀性，而碳酸钙是许多海洋生物的外骨骼材料。Feely 等人（5月22日发布于网上，见1490页）在加拿大南部至墨西哥北部选取13个水文断面进行研究，结果表明，在2007年大陆架的很多地方发生了潜在的腐蚀性海水上涌。这种季节性的海水上涌至大陆架是一种自然现象，但是含有人为来源的二氧化碳的海水不断曝露于大陆架，具有潜在的破坏性。