科学素养与现象阐释·英语30篇（5）
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How Oceanic Carbonate Chemistry Buffers Atmospheric CO₂ Fluctuations
海洋碳酸盐化学如何缓冲大气CO₂波动
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Seawater contains a natural pH buffer system based on dissolved CO₂, carbonic acid, bicarbonate, and carbonate ions.
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When atmospheric CO₂ rises, Henry’s law drives increased dissolution—converting CO₂ into HCO₃⁻ with minimal pH change.
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This buffering capacity has absorbed ~30% of anthropogenic CO₂ emissions since the Industrial Revolution.
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However, excess H⁺ from carbonic acid formation gradually depletes carbonate ion concentration—threatening shell-forming organisms.
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The saturation state (Ω) of aragonite—a key biomineral—has declined 15% globally since 1880.
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Upwelling zones off Peru and California show seasonal undersaturation, causing oyster larvae mortality spikes.
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Ocean alkalinity enhancement proposals aim to restore buffering capacity by adding finely ground olivine.
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Modeling future Ω requires coupling atmospheric transport, riverine alkalinity fluxes, and biological calcification rates.
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Fisheries management now incorporates carbonate chemistry forecasts alongside traditional stock assessments.
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Carbonate buffering explains why ocean pH dropped only 0.1 units despite 120 ppm CO₂ increase—a feat terrestrial systems lack.
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Its diminishing efficacy signals a tipping point where marine ecosystems lose adaptive capacity.
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This chemistry operates silently beneath policy debates—yet defines the biogeochemical ceiling for climate mitigation.