Mechanistically understanding biomineralisation and ancient ocean chemistry changes to facilitate robust climate model validation

对地球地质历史中自然高于现代大气二氧化碳的温暖间隔的研究具有至关重要的社会意义，因为这些信息提供了：1)一种确定随着我们燃烧化石燃料，温度可能上升多少的方法；2)一种评估最先进气候模型质量的经验方法。大多数过去的气候信息来自“代用品”，这些代用品将化石材料化学成分的微小变化与其形成环境联系起来，其中有孔虫（单细胞海洋生物）的壳可能代表了最广泛使用的档案。不幸的是，没有一个代理制度是完美的，因为它们都对不止一个因素作出反应。例如，基于有孔虫地球化学的古温度计对形成它们的海水的温度和化学成分都很敏感，而海水的化学成分随着时间的推移而发生变化，人们对这种变化知之甚少。此外，对于有孔虫构建外壳的过程中涉及的基本机制，甚至没有达成共识，因此我们不知道代理重建何时可能有偏见。阿米巴将直接解决这两个问题，方法是对现存有孔虫进行极为新颖的观察，以确定它们是如何形成外壳的，并生成海洋中过去化学变化的必要记录。这将促进定量代理数据解释的逐步变化，改变这些数据集的效用。AMOEBA将把这些知识应用到一个新的新生代数据汇编中，对关键温室间隔期间的地球温度进行准确估计。因此，通过促进下一代模型数据的比较，最先进的气候模型捕捉温室变暖关键特征的能力将首次得到明确的评估。

The study of warm intervals in Earth's geologic past with naturally higher-than-modern atmospheric CO2 is of crucial societal importance because this information provides: i) a way of determining how much temperature is likely to rise as we burn fossil fuels, and ii) an empirical means of assessing the quality of state-of-the-art climate models. Most past climate information comes from 'proxies', which relate small changes in the chemical composition of fossil materials to their environment of formation, of which the shells of the foraminifera (unicellular marine organisms) possibly represent the most widely used archive. Unfortunately, no proxy system is perfect, in that they are all responsive to more than one factor. For example, paleothermometers based on the geochemistry of foraminifera are sensitive to both the temperature and chemistry of the seawater they formed in, the latter of which has changed through time in a poorly understood way. In addition, there is no consensus view on even the basic mechanisms involved in the process by which foraminifera build their shell, such that we don't know when proxy reconstructions are likely to be biased. AMOEBA will directly tackle both issues by making extremely novel observations of living foraminifera to determine how they form their shell, and by generating the necessary records of past chemical change in the oceans. This will facilitate a step-change in the interpretationof quantitative proxy data, transforming the utility of such datasets. AMOEBA will apply this knowledge to a new Cenozoic data compilation, producing accurate estimates of Earth's temperature during key greenhouse intervals. Thus, by facilitating the next generation of model-data comparison, the ability of state-of-the-art climate models to capture key features of greenhouse warmth will be unambiguously assessed for the first time.