二酸化炭素濃度の上昇に伴う酸性化の加速（Carbon-Rich Waters Are Becoming More Acidic as Atmospheric CO2 Levels Rise）

2025-11-13 ワシントン大学（UW）

＜関連情報＞

• https://www.washington.edu/news/2025/11/13/carbon-rich-waters-are-becoming-more-acidic-faster/
• https://www.nature.com/articles/s41467-025-63207-6

カリフォルニア海流の1世紀にわたる変化：湧昇システムが酸性化を増幅 A century of change in the California Current: upwelling system amplifies acidification

Mary Margaret V. Stoll,Curtis A. Deutsch,Hana Jurikova,James W. B. Rae,Hartmut Frenzel,Anne M. Gothmann,Simone R. Alin & Alexander C. Gagnon
Nature Communications  Published:13 November 2025
DOI:https://doi.org/10.1038/s41467-025-63207-6

Abstract

Predicting the pace of acidification in the California Current System (CCS), a productive upwelling system that borders the west coast of North America, is complex because the anthropogenic contribution is intertwined with other natural sources. A central question is whether acidification in the CCS will follow the pace of increasing atmospheric CO₂, or if climate effects and other biogeochemical processes will either amplify or attenuate acidification. Here, we apply the boron isotope pH proxy to cold-water orange cup corals to establish a historic level of acidification in the CCS and the Salish Sea, an associated marginal sea. Through a combination of complementary modeling and geochemical approaches, we show that the CCS and Salish Sea have experienced amplified acidification over the industrial era, driven by the interaction between anthropogenic CO₂ and a thermodynamic buffering effect. From this foundation, we project future acidification in the CCS under elevated CO₂ emissions. The projected change in pCO₂ over the 21^st century will continue to outpace atmospheric CO₂, posing challenges to marine ecosystems of biological, cultural, and economic importance.