RCN: Improving reconstructions of Cenozoic pCO2 and temperature change

大气二氧化碳（pCO 2）对地球温室效应的贡献已经知道了一个多世纪，但更高的大气CO2浓度对气候，陆地和海洋生态系统的详细影响仍然是不确定的。地球历史可以帮助科学家提高他们对二氧化碳分压和全球气候变化之间的相互作用的理解，通过提供记录在化石贝壳和分子的化学成分中的二氧化碳分压和气候的过去变化的记录。在地质学的过去，地球经历了二氧化碳分压和气候的深刻变化，但重建仍然具有挑战性。这是因为许多产生化石的生物现在已经灭绝，景观已经改变，海洋和大气的化学成分已经改变。虽然研究人员积极探索个人档案和模型的敏感性，较少的努力已经花在发展一个更广泛的观点的相对优势和不同的方法的弱点。这个研究协调网络将把古气候/古海洋学研究界聚集在一起，目标是公开承认不确定性，建设性地共同努力减少不确定性，并促进对过去和未来气候变化的理解。为了实现这一目标，将举办两个研讨会，将汇集现有和未来的专家，从陆地和海洋档案中重建和建模古pCO 2。研讨会将重点关注过去6500万年地球历史中pCO 2代理和碳循环模型的验证机会。将特别注意在选定的时间段内进行代用品和模型的交叉校准和敏感性研究。将建立一个古二氧化碳分压数据库，并将发表关于最佳做法准则的立场文件。将讨论碳循环和地球化学模型的机会，以改进数据综合，并确定需要增加数据的区域。为了提高美国国内的能力建设，每年将为多达4名美国科学家提供参加分析和模型培训计划的机会，在那里他们将从该领域的专家那里学习新技术。为了确保所有研究方面和人口统计都得到适当的涵盖，一个由16名成员组成的指导委员会将提名专家讲习班参加者，并从（国际）国家申请人库中挑选有前途但不太成熟的候选人。

The contribution of atmospheric carbon dioxide (pCO2) to Earth's greenhouse effect has been known for more than a century, yet the detailed impacts of higher atmospheric CO2 concentrations on climate, terrestrial, and marine ecosystems are still subject to uncertainty. Earth history can aide scientists in improving their understanding of the interaction between pCO2 and global climate change, by providing records of past variations in pCO2 and climate recorded in the chemical composition of fossil shells and molecules. In the geologic past, Earth experienced profound changes in pCO2 and climate, but reconstructions remain challenging. This is due to the fact that many of the fossil-producing organisms are now extinct, landscapes have changed, and the chemical composition of the oceans and atmosphere have changed. While researchers actively explore individual archives and model sensitivities, less effort has been spent on developing a broader view of relative strengths and weaknesses of different approaches. This research coordination network will bring the paleoclimate/palcoeanographic research community together with the goal of openly recognizing uncertainties, constructively and jointly working to reduce them, and advancing the understanding of past and future climate change. To achieve this goal, two workshops will be held, which will bring together established and future specialists in reconstructing and modeling paleo-pCO2 from terrestrial and marine archives. The workshops will focus on validation opportunities for pCO2 proxies and carbon cycle models over the last 65 million years of earth history. Particular attention will be paid to proxy and model cross-calibrations and sensitivity studies in select time periods. A paleo-pCO2 database will be established, and position papers on best practices guidelines will be published. Opportunities will be discussed for carbon cycle and biogeochemical models to improve data syntheses and identify regions for desirable data additions. To improve capacity building within the US, up to four US scientists per year will be provided with an opportunity to enter an analytical and model training program, where they will learn new techniques from experts in the field. To ascertain that all research aspects and demographics are appropriately covered, a 16-member steering committee will both nominate expert workshop participants but also select promising but less well established candidates from an (inter-)national applicant pool.