Quantifying responses to abrupt climate change in the Andes, South America: Empirical data and model synergies

在南美洲，超过80%的人口依赖山区的饮用水和农业用水。这种水排放的主要来源是储存在山区冰川中，众所周知，由于气候变化，这些冰川正在以前所未有的速度退缩。一旦非洲基利曼哈罗山顶的冰川融化，世界上所有的热带冰川都将位于安第斯山脉（Kaser，1999年），主要位于玻利维亚或秘鲁。因此，山地冰川是干旱、季节性高地环境中的重要水源，也是衡量当今和未来气候变化的一个非常敏感的指标。这些冰川反过来又为安第斯高地的湖泊和沼泽提供水源，使它们成为气候变化以及包括土地使用在内的相关环境变化的非常敏感的储存库。14.因此，秘鲁安第斯山脉的安第斯湖泊和沼泽为探索气候变化的历史及其对环境的影响提供了机会，并为未来的设想提供了重要的古模拟。在安第斯山脉进行的一些考古、古气候和古环境研究已经突出表明，过去的气候波动、重大的文化扩张和崩溃以及经济和社会政治结构的相关变化之间可能存在联系，主要是在过去2000年里。然而，这种关系仍然不清楚，需要进行更高的空间和时间分辨率的研究，这些数据才能在未来的情景中发挥作用，特别是在有关水的供应和管理的问题上。因此，安第斯高地的环境是测试各种气候和环境代理的敏感性以及人类对气候变化反应的性质和时间的理想天然实验室。此外，安第斯高地系统是人类社区1000多年来的重要农业基地，因此对未来尤为重要，因为粮食安全和对可行农业用地的需求是关键。该项目旨在将同位素和古生态学数据与定量建模相结合，以确定哥伦比亚气候和环境变化对秘鲁安第斯山脉土地利用和人类活动的影响。在过去15年中，获得经验性气候和环境重建数据的技术越来越多。我们现在能够收集时间完整的材料（湖芯、泥炭、沼泽和洞穴沉积物），这些材料可以准确地确定日期，并包含一系列环境和气候标志和指纹。然而，到目前为止，这些代理主要是孤立地或偶尔作为组件的组合进行研究。这个学生奖学金申请将汇集来自有机地球化学（脂质，粪便和胆汁生物标志物），古生态学（来自动物的非花粉palynomorphs），无机地球化学（重和轻稳定同位素）和来自高地安第斯湖和沼泽系统的古代DNA的数据，以探索人类职业和农业之间的联系，以应对过去的气候变化。将在秘鲁的高地湖泊（Chillón和Urubamba山谷）中采集两个新地点的岩心，分析上述多代理信号，并将其添加到美国海洋和大气管理局古气候数据库（https：//www.ncdc.noaa.gov/）现有岩心材料的单一记录中。这些环境和气候指标将与最新的气候模型结合使用，以提供有关关键气候和环境指标的预测。然后，将使用一个基于地理的预测模型（在ArcGIS ModelBuilder中建立），将所有数据联合收割机结合在一起，以产生环境和气候敏感性的时间切片地理输出，这将有助于应对未来的气候变化。

In South America, more than 80% of the population is reliant on water supplies from mountainous areas for drinking water and agriculture. The main source of this water discharge is stored in mountain glaciers, which are known to be retreating at an unprecedented rate due to climate change. The severity of this problem is highlighted by the fact that once the glacier at the top of Mt Kilimanjaro in Africa has melted, all of the world's tropical glaciers will be located in the Andes (Kaser, 1999), mainly in Bolivia or Peru. Thus, mountain glaciers are important water sources in the dry, seasonal upland environments, but are also a very sensitive measure of present day and future climate change. These glaciers in turn feed upland Andean lakes and mires making them very sensitive repositories of climate change, and associated changes in the environment, including land-use. .Therefore, Andean lakes and mires in the Peruvian Andes provide an opportunity to explore the history of climate change and its impact on the environment, and to provide an important palaeo-analogue for future scenarios. A number of archaeological, palaeoclimatic and palaeoenvironmental studies in the Andes have already highlighted the possible connection between past climate fluctuations, and significant cultural expansion and collapse, and associated changes in economic and socio-political structures, mainly over the last 2000 years. However, the relationship remains unclear, and there is a need for much higher spatial and temporal resolution studies before these data are useful in future scenarios, especially with respect to issue surrounding water availability and management. Highland Andean environments are thus the ideal natural laboratory to test the sensitivity of various climate and environmental proxies, and the nature and timing of human responses to climate change. In addition, the upland Andean systems have been an important agricultural base for human communities for 1000's of years making them particularly important for the future where food security and demand for viable agricultural land are key.Aim: This project aims to integrate isotope and palaeoecological data with quantitative modelling to determine the impact of pre-Columbian climate and environmental change on land use and human occupation for the Peruvian Andes. In the last 15 years techniques for obtaining empirical climate and environmental reconstruction data has become increasingly available. We are now in a position to be able to collect time-integrated materials (lake cores, peat, mire and cave deposits) that can be dated accurately, and contain a range of environmental and climatic markers and fingerprints. However, until now these proxies have largely been investigated in isolation or occasionally as a combination of components. This studentship application will bring together data from organic geochemistry (lipid, faecal and bile biomarkers), palaeoecology (non-pollen palynomorphs from animals), inorganic geochemistry (heavy and light stable isotopes) and ancient DNA from upland Andean lake and mire systems to explore the connections between human occupation and agriculture in response to past climate changes. Two new sites will be cored in upland lakes from Peru (Chillón and Urubamba Valleys) and analysed for multi-proxy signals above and added to singular records from existing core material available on the NOAA palaeoclimate database (https://www.ncdc.noaa.gov/). These environmental and climatic markers will be used in conjunction with the latest climate models to offer predictions regarding key climate and environment indicators. A predictive geographical-based model (built in ArcGIS ModelBuilder) will then be used to combine all the data together to produce time-sliced geographical outputs of environmental and climate sensitivity which will be useful for coping with future climate change.