Climate sensitivity and the rate of ocean acidification: future impacts, and implications for experimental design
Climate sensitivity and the rate of ocean acidification: future impacts, and implications for experimental design
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DOI：
10.1093/icesjms/fsw189
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发表时间：
2017-05-01
影响因子：
3.3
通讯作者：
Humphreys, Matthew P.
中科院分区：
文献类型：
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作者：
Humphreys, Matthew P.
全球平均地表温度和二氧化碳(CO2)分压在大气和海洋中都在增加。海洋对二氧化碳的吸收导致被称为海洋酸化(OA)的pH下降，这也改变了其他具有重要生物意义的碳酸盐系统变量，如碳酸盐矿物饱和状态。在这里，我们讨论“温度缓冲”效应如何在比人们通常所理解的更基本的水平上从化学上将变暖和变暖联系起来，这意味着海水变暖可以减轻变暖造成的一些不利的生物影响。在全球平均意义上，相对于二氧化碳增加的升温速度可以用气候敏感性(CS)来量化，其确切值是不确定的。最初看来，更大的CS会因此减少OA的负面影响。然而，根据未来人为二氧化碳排放的轨迹，二氧化碳增加速率对CS的依赖可能会增强、抵消甚至逆转温度缓冲效应。区域偏离全球平均海水温度和二氧化碳吸收趋势可能会影响当地对海洋气候变化的反应。例如，在北冰洋，通过缓冲温度来缓解海洋酸化的影响可能特别有效，因为那里的表层海水升温速度大于全球平均水平，水中二氧化碳浓度的增加可能比其他地方慢。一些碳酸盐系统变量比其他变量受到的影响更大，这突显了需要建立一种机制上的理解，准确地了解哪些变量对每个生物地球化学过程是重要的。在设计实验以确定海洋物种和生态系统对变暖和海洋酸化的反应时，应考虑到海洋碳酸盐系统的温度缓冲，以便其结果准确地反映未来的条件，从而在应用于地球系统模型时能够产生现实的预测。
The global mean surface temperature and partial pressure of carbon dioxide (CO2) are increasing both in the atmosphere and ocean. Oceanic CO2 uptake causes a decline in pH called ocean acidification (OA), which also alters other biologically important carbonate system variables such as carbonate mineral saturation states. Here, we discuss how a "temperature buffering" effect chemically links the rates of warming and OA at a more fundamental level than is often appreciated, meaning that seawater warming could mitigate some of the adverse biological impacts of OA. In a global mean sense, the rate of warming relative to the CO2 increase can be quantified by the climate sensitivity (CS), the exact value of which is uncertain. It may initially appear that a greater CS would therefore reduce the negative influence of OA. However, the dependence of the rate of CO2 increase on the CS could enhance, nullify or even reverse the temperature buffering effect, depending upon the future trajectory of anthropogenic CO2 emissions. Regional deviations from the global mean seawater temperature and CO2 uptake trends could modulate local responses to OA. For example, mitigation of OA impacts through temperature buffering could be particularly effective in the Arctic Ocean, where the surface seawater warming rate is greater than the global mean, and the aqueous CO2 concentration might increase more slowly than elsewhere. Some carbonate system variables are more strongly affected than others, highlighting the need to develop a mechanistic understanding of precisely which variables are important to each biogeochemical process. Temperature buffering of the marine carbonate system should be taken into account when designing experiments to determine marine species and ecosystem responses to warming and OA, in order that their results accurately reflect future conditions, and therefore can generate realistic predictions when applied to Earth system models.