Oceans acidification and arctic carbonates

二氧化碳在大气中的积累，被认为是全球变暖的罪魁祸首，在海洋中也有同样令人担忧的后果：海洋栖息地的迅速酸化。大气中二氧化碳的积累确实伴随着海洋中同样大量的二氧化碳积累。一旦溶解，二氧化碳分解成一种更具反应性的化合物，与氢结合形成碳酸。海洋中的碳酸对构建坚硬碳酸钙骨架的生物体（例如珊瑚）施加了巨大的压力，其中许多以微观形式存在，构成了海洋食物链的基础。大气中的二氧化碳浓度仅比工业化前高出35%，但海洋酸化正在进行中。我们将研究古代海洋对大气中二氧化碳显著增加的反应，这一增加发生在3.25亿至2.5亿年前，当时浓度上升到现代值的5至10倍。我们将调查是否是海洋酸度的相关增加导致了分泌碳酸钙的动物和植物的逐步灭绝。这一现象最终导致了地球上最大规模的物种灭绝，当时95%的硬壳生物已经消失。我们将在加拿大北极地区研究这种现象，那里没有植被的山脉的极好暴露使其适合进行这种研究。

The buildup of carbon dioxide in the atmosphere, blamed for global warming, has an equally alarming offspring in the oceans: the rapid acidification of marine habitats. The accumulation of atmospheric carbon dioxide is indeed accompanied by an equally large buildup of carbon dioxide in the ocean. Once dissolved, carbon dioxide breaks into a more reactive compound that combines with hydrogen to form carbonic acid. Carbonic acid in the oceans puts enormous pressure on organisms that build a hard calcium carbonate skeleton (for example, corals), many of which exist in microscopic forms and constitute the base of the marine food chain. Carbon dioxide concentration in the atmosphere is only 35% above pre-industrial values, and yet ocean acidification is well underway. We will study the response of ancient oceans to a far more significant increase in atmospheric carbon dioxide which occurred between 325 to 250 million years ago when concentrations rose 5 to 10 times the modern values. We will investigate whether it is the associated increase in ocean acidity that contributed to a progressive eradication of calcium carbonate-secreting animals and plants. This phenomenon culminated in the largest mass extinction on Earth, when 95% of hard-shelled organisms had disappeared. We will study this phenomenon in the Canadian Arctic where the superb exposures of vegetation-free mountains lend themselves to such research.