The impacts of rapidly receding glaciers on proglacial freshwater resources and ecological services

人为引起的气候变化是我们这个时代最紧迫的环境问题，威胁着我们的水和食物供应安全、生态系统和人类健康以及社会经济健康。的确，获得清洁淡水及其提供的自然产品和服务是一项基本人权。冰川为世界六分之一以上的人口提供必需的淡水，但气候变暖正在导致全球冰川量减少，下游径流也随之发生变化。减少温室气体排放以保护我们剩余的冰川和河流对于确保一定程度的全球水安全至关重要。然而，同样重要的是量化冰川、生物地球化学和湖泊过程的变化，这些变化已经发生在冰川后退前形成的快速演变的前冰川景观中。评估这些变化将使我们了解冰川退缩将如何影响淡水质量和下游的生态系统功能，那里是大多数人口生活和工作的地方。例如，冰川质量的损失可能导致大量营养物质、古代有机碳和历史上保存在冰川冰中并埋在冰川下的污染物的释放，所有这些都可能影响下游的淡水质量、生产力、资源和生态服务。相比之下，当冰川河流穿过新出现的前冰川景观时，它们实际上可能会通过化学风化作用消耗大气中的二氧化碳（CO2），这些化学风化作用是它们携带的一些大量可用的新鲜粉碎的细颗粒矿物。因此，我提出的研究计划有四个目标，每个目标都与研究生项目相一致，并对本科生、因纽特人和其他北方民族以及实验室技术人员进行额外的培训：(1)表征冰川前河流和湖泊中消耗二氧化碳的地球化学过程；(2)确定全球二氧化碳消耗量；(3)量化前冰期湖泊的生物生产力；(4)量化全球前冰期淡水化学的季节、年际和空间格局。这一创新的、跨学科的合作研究和培训计划将产生两大科学影响：它将(1)增强我们对区域和全球二氧化碳预算的理解（目标1）和(2)提高我们对区域和全球前冰期淡水质量和服务的认识（目标3a，对基本粮食和饮用水安全至关重要的资源）。事实上，全球许多人口的传统生活方式依赖于源自冰川的至关重要且极易受到破坏的淡水资源。因此，增加我们对这些资源的了解，以及它们在未来如何变化，是至关重要的。

Human-induced climate change is the most pressing environmental issue of our time, threatening the security of our water and food supply, ecosystem and human health, and socioeconomic wellness. Indeed, access to clean freshwater, and the natural goods and services it provides, is a fundamental human right. Glaciers provide essential freshwater to more than a sixth of the world's population, yet climate warming is resulting in a decline of global glacier volume, with coincident changes to downstream runoff. Lowering greenhouse gas emissions to preserve our remaining glaciers and river flows is vital for ensuring some level of global water security. However, it is equally essential to quantify the changes in glaciological, biogeochemical, and limnological processes that are already occurring in the rapidly evolving proglacial landscapes forming in front of retreating glaciers. Assessing these changes will allow us to understand how glacial retreat will influence freshwater quality and ecosystem function further downstream, where most of the human population lives and works. For example, loss of glacial mass may result in the large releases of nutrients, ancient organic carbon and contaminants historically archived in glacial ice and buried beneath glaciers, all of which could impact downstream freshwater quality, productivity, resources and ecological services. In contrast, as glacial rivers cross newly-emerged proglacial landscapes, they may actually consume atmospheric carbon dioxide (CO2) via chemical weathering of some of the abundantly available freshly comminuted fine-grained minerals they entrain. As such, there are four objectives to my proposed research program, each aligning with a graduate student project, and additional training of undergraduate students, Inuit and other northern peoples, and laboratory technicians: (1) characterize the geochemical processes that consume CO2 in proglacial rivers and lakes; (2) determine the global extent of this CO2 consumption; (3) quantify biological productivity in proglacial lakes; and (4) quantify seasonal, interannual and spatial patterns in global proglacial freshwater chemistry. This innovative, interdisciplinary, and collaborative research and training program will have two major scientific impacts: it will (1) enhance our understanding of regional and global CO2 budgets (Objectives 1 and (2) improve our knowledge of regional and global proglacial freshwater quality and services (Objectives 3a resource that is vital for basic food and drinking water security. Indeed, the traditional lifestyles of many human populations around the globe rely on the crucial and highly vulnerable freshwater resources that originate from glaciers. Therefore, increasing our knowledge of these resources, and how they may change in the future, is critical.