Evolution of Carbon Cycle Dynamics (eCCD)

碳循环动力学的演变 (eCCD)

基本信息

批准号：
NE/H022554/1
负责人：
Heiko Pälike
金额：
$ 6.51万
依托单位：
University of Southampton
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2010
资助国家：
英国
起止时间：
2010 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FH022554%2F1
关键词：
Evolution Carbon Cycle Dynamics eCCD

项目摘要

see lead Institution (Bristol): Evolution of Carbon Cycle Dynamics (eCCD) - Summary The global carbon cycle: how much carbon is stored in its interconnected reservoirs (ocean, atmosphere, biosphere, sediments) as well as the fluxes between them, changes with time. For instance, we know from the geological record that the concentration of CO2 in the atmosphere has varied enormously over the last few hundred of millions of years. The chemistry of the oceans also slows varies with time, and the organisms living within the ocean change and evolve. The details of how the carbon cycle 'works', and of particular importance, how well (or not) the concentration of CO2 in the atmosphere (and hence climate) is regulated, thus also changes on geological time-scales. This creates challenges, for instance, in understanding the causes and consequences of past global warming like events and how they can be related to the future. The sediments slowly accumulating in the deep ocean reflect everything that goes on around them and above them, both chemically and biologically. In particularly, the mineral calcium carbonate (CaCO3), which can be found in the form of chalk and limestone rocks today, is a material commonly used in constructing shells and skeletons by marine organisms. Hence, the amount of CaCO3 being buried in sediments tells us something about ancient organisms and ecosystems. In addition, CaCO3 will start dissolving in seawater if the conditions are acidic or the depth (and thus pressure) is very intense, such as at the very bottom of the open ocean. How much of the CaCO3 originally created by organisms that remains and is not dissolved in sediments, thus also tells us something about past ocean chemistry, depth, and when data from many locations is available, ocean circulation. Looking for subtle changes in the composition of ancient mud in hundreds and hundreds of meters of sediment core recovered from the ocean floor by drill ship would be a little like looking for a needle in a haystack. However, nature has been kind us and the transition from white-colored sediments rich in the shells of carbonate marine organisms to clays devoid of carbonate is easy to spot. This point represents a balance between the amount of shells deposited to the sediments and the rate of dissolution. Hence a balance between surface ocean biological processes and deep ocean chemical and circulation processes. In this project by compiling the records from hundreds of different sediment cores recovered in the past decades, we will reconstruct how this balance point has change in depth and time in the different ocean basins. Because sediment records exist as far bask as the Mesozoic and well before the dinosaurs went extinct, we will start there. However, the interpretation of the curve we will produce is not straightforward, because multiple environmental changes can all push and pull this balance point in different directions and with different strengths. We will there fore also configure a computer model representation of the Earth's climate and oceans, its carbon cycle, ocean chemistry, and the composition of sediments in the deep sea for these times in the past. We will use this to explore how the different possible changes in the carbon cycle affect the balance point, and by comparing to our new curve through time, interpret how the carbon cycle has changed over the past 150 million years. This will also allow us to understand how the sensitivity of the carbon cycle and hence climate changes in time to being perturbed, such as by massive greenhouse gas releases. Hence we will not only be able to answer the question: do we live in a particularly 'lucky' or 'unlucky' time in terms of how sensitive our global environment is to the burning of fossil fuels, but we will know why the Earth system responds with a certain degree of sensitivity.

参见铅机构（布里斯托尔）：碳循环动力学的演变（ECCD） - 总结全球碳循环：在其互连的储层中存储多少碳（海洋，大气，生物圈，沉积物）以及它们之间的磁通量以及它们之间的磁通量随时间而变化。例如，我们从地质记录中知道，在过去的几亿年中，大气中二氧化碳的浓度越来越大。海洋的化学也随着时间而变化，海洋内的生物会变化和进化。碳循环“工作原理”的细节，特别重要的是，调节了大气中二氧化碳浓度的浓度（以及因此气候），从而在地质时间尺度上也发生了变化。例如，这引起了挑战，例如了解过去全球变暖的原因和后果，例如事件以及它们与未来如何相关。在深海中慢慢积累的沉积物反映了它们周围和在它们上方的一切，无论是化学和生物学上的。尤其是，如今可以以粉笔和石灰石岩石的形式找到碳酸钙（CACO3），是一种通常用于海洋生物体构造壳和骨骼的材料。因此，埋在沉积物中的CACO3量告诉我们有关古代生物和生态系统的一些信息。此外，如果条件是酸性或深度（因此压力）非常强，例如在开放海洋的底部，CACO3将开始溶解在海水中。最初由剩下且不溶于沉积物中的生物产生的CACO3，因此也告诉我们一些有关过去的海洋化学，深度以及许多位置的数据可用的数据，海洋循环。寻找在数百米的沉积物核心从海底回收的数百米的沉积物芯的构成的微妙变化，就像在干草堆里寻找针头一样。然而，自然一直是我们的友善，从富含碳酸盐海洋生物壳的白色沉积物过渡到没有碳酸盐的粘土。这一点表示沉积物沉积物的壳数量与溶解速率之间的平衡。因此，表面海洋生物过程与深海化学和循环过程之间的平衡。在该项目中，通过在过去几十年中收回数百种不同沉积物核心的记录来编制记录，我们将重建该平衡点如何在不同的海洋盆地的深度和时间变化。由于沉积物唱片的存在与中生代一样，在恐龙灭绝之前，我们将在那里开始。但是，我们将产生的曲线的解释并不直接，因为多种环境变化都可以以不同的方向推动和提升这个平衡点，并且具有不同的优势。我们还将在那里配置地球气候和海洋的计算机模型表示，其碳循环，海洋化学和深海中沉积物的成分过去过去。我们将使用它来探索碳周期的不同可能变化如何影响平衡点，并通过与我们的新曲线进行比较，解释了碳循环在过去15000万年中的变化。这也将使我们能够理解碳循环的敏感性以及气候在扰动中的时间变化，例如通过大量的温室气体释放。因此，我们不仅能够回答这个问题：就我们的全球环境对燃烧化石燃料的敏感性而言，我们生活在一个特别的“幸运”或“不幸”的时期中，而且我们会知道为什么地球系统会以一定程度的敏感性做出反应。