Regional Ecosystem & Biogeochemical Impacts of Ocean Acidification - a modelling study.

气候变化是当今时代政府和社会关注的主要问题之一。绝大多数科学家都认为，原因是工业时代人类活动排放了大量的二氧化碳。大气中二氧化碳含量增加的后果之一是海洋酸化（OA）。海洋吸收了相当大比例的额外二氧化碳，这些二氧化碳在水中反应，增加了酸度。至少在公共领域，这一点稍微不那么为人所知，但它是基于无争议和高度接受的科学认识，最近通过对海洋酸度增加的精确测量得到了证实。因此，在接下来的几十年里，海洋将受到气候变化（温度升高，环流和混合变化）和酸度增加的影响。这里变得复杂了。已知酸化会影响对调节海洋生态系统很重要的几个不同过程，不同的物种表现出不同的敏感性。温度和洋流的变化将导致特定物种的分布发生变化，混合率的改变（海洋沃茨的搅动）将影响基本营养物质的供应。此外，如果这些物种受到温度升高的影响，一些生理过程变得更容易受到酸度诱导的影响。海洋的酸度（或碳酸盐系统）也会对温度和陆地效应（降雨量变化或冰融化）产生反应，而这些效应在全球变暖的情况下可能会发生。总之，预测高CO2（气候和OA）对海洋系统的影响是一个非常复杂的问题。许多科学实验和观测方案目前正在调查气候和酸度如何影响海洋系统。然而，我们试图综合上述各种影响并对未来做出预测的唯一方法是发展数学模型。在这项提案中，我们的目标是开发现有的模型，覆盖英国周围的陆架海（具有巨大的资源效益）和北极地区（对气候变化和OA都有迫在眉睫的风险），并提高我们对影响的程度和时间尺度的理解和确定性。我们将使用的模型系统结合了流体力学，海洋化学和海洋生态系统的代表性以及驱动它们的过程，使其成为测试气候和OA综合影响的理想选择。这些模型将受到最新和最准确的气候变化预测的影响，我们将至少比较一个高排放情景-假设我们在全球范围内不限制二氧化碳的产生，以及一个低排放情景-假设全球将采取重大措施减少二氧化碳的产生。利用实验和观测项目产生的信息，我们将改进模型中对酸度敏感的化学和生理过程的描述。通过比较模型系统的后报与观测数据，我们将建立模型的准确性，并通过敏感性分析测试单个过程或参数的不确定性。因此，我们的目标不仅是提供对未来状态的预测，而且是对确定性的估计。对该项目将产生的影响和时间尺度的更好理解将直接纳入联合王国政府的咨询进程，并为制定国家和国际缓解和适应战略提供基础。

Climate change is one of the main governmental and societal concerns of the current era. The cause, the emissions of huge quantities of carbon dioxide (CO2) by human activities during the industrial era, is accepted by the vast majority of scientists. One of the consequences of increased atmospheric CO2 is Ocean Acidification (OA). The seas absorb a significant proportion of the extra CO2 which reacts in water to increase acidity. This is slightly less well known, at least in the public domain, but is based on uncontroversial and highly accepted scientific understanding and recently verified by precise measurements of the oceans increasing acidity. So over the next few decades the oceans will be impacted by changing climate (increased temperature, changing circulation and mixing) and by increasing acidity. Here it gets complicated. Acidification is known to impact several different processes that are important in regulating the marine ecosystem and different species exhibit different sensitivities. Changing temperature and currents will cause the distributions of particular species to alter and modification of mixing rates (the stirring of the oceans waters) will impact the supply of essential nutrients. Further some physiological processes become more prone to acidity induced effects if those species are subject to increased temperature. The acidity (or carbonate system) of the oceans is also responsive to temperature and to terrestrial effects (changing rainfall or ice melt) that are likely to occur given global warming. In summary predicting the impact of high CO2 (climate and OA) on marine systems is a very complex question. Many scientific experiments and observational programmes are currently investigating how climate and acidity impact the marine system. However the only method we have for trying to synthesise the various impacts mentioned above and make predictions into the future are the development of mathematical models. Within this proposal our aims are to develop existing models that cover the shelf seas around the UK (which have huge resource benefits) and the Arctic region (which is imminently at risk to both climate change and OA) and improve our understanding and certainty of both the magnitude and timescale of impacts. The model system we will use incorporates hydrodynamics, marine chemistry and a representation of marine ecosystems and the processes that drive them, making it ideal to test the combined effects of climate and OA. The models will be forced by the latest and most accurate predictions of climate change and we will compare at least a high emissions scenario - which assumes that globally we do not restrict CO2 production, and a low emissions scenario - which assumes that globally significant steps will be taken to reduce CO2 production. Using information generated by experimental and observational programmes we will improve the description of acidity sensitive chemical and physiological processes in the model. By comparing hind-casts of the model system with observed data, we will establish the accuracy of the model and test uncertainty in individual processes or parameters by sensitivity analysis. We therefore aim to deliver not only predictions of future states but estimates of certainty. The improved understanding of impacts and timescales that this project will generate will be fed directly into the UK Government's advisory process and underpin the development of national and international mitigation and adaptation strategies.