Biogeochemical processes and ecosystem function in changing polar systems and their global impacts (BIOPOLE)

气候变化正威胁着海洋为人类提供的两项关键生态系统服务：食物和大气碳储存。极地地区对两者都有重大影响，但也正在经历最剧烈和最迅速的变化。需要更好地了解影响海洋中营养物质供应和生物加工方式的因素，以评估未来的风险，量化地球系统和人类对这一支持全球生产力和渔业的重要全球功能的依赖。氮(N)和磷(P)等关键营养物质在全球海洋中的分布并不均匀，但它们在极地地区过量，并通过海洋环流从那里出口到低纬度地区。生物物质是通过氮、磷和碳(C)（以及其他微量元素）的组合产生的，在全球海洋的大多数地区，这种组合的比例大致相同。然而，在两极地区发现的比率有很大不同。这是因为，首先，极地营养物质有多种来源（冰川、海冰、河流和其他海洋）。其次，极地生态系统以不同的方式处理这些营养物质和碳。这导致i)营养过剩，从极地海洋输出并支持全球生产力，以及ii)大气中的碳运输到远离大气的深水中。紧迫的问题是，两极的快速气候变化正在改变营养物的供应和生态系统的处理能力。这不仅威胁到人类赖以生存的海洋食物储备，也威胁到海洋中碳的生物减少，而海洋是全球气候的关键调节器。由于地球系统模型（ESMs）中极地生物地球化学和生态系统过程的代表性不足，我们充分描述和预测这一威胁的能力受到限制。BIOPOLE代表并连接了英国许多主要的环境研究机构，他们将与国内和国际合作伙伴一起解决这个问题。我们提出了一项雄心勃勃的计划，将集中观察、新颖分析和计算机模拟结合起来，从根本上提高我们测量、理解和预测极地地区营养供应和碳储存如何受到气候变化的影响的能力。BIOPOLE将进一步确定和量化对海洋生产力和渔业的更广泛的全球影响。我们将在两极取样和收集数据，以从地球系统的角度来看待这个问题。最新的实验和观测技术将描绘独特的极地群落对碳和养分的处理。它将包括使用新颖的自主技术来收集比单独船只更长的时间和更大的区域的数据。产生的新认识将为全球模式提供信息，并与其他模式方法一起使用，以更好地量化极地海洋在维持全球海洋初级生产力和鱼类种群方面发挥的作用，并预测未来趋势。两极地区的气候变化速度比其他任何地区都快，导致海冰减少和冰川融化。显然，迫切需要全面了解这些变化对极地地区本身和更广泛的地球系统的生物地球化学和生态系统层面的影响。随着冰的消退，脆弱而具有全球重要性的生态系统需要国际保护，这取决于通过协调的极地科学建立强有力的科学证据。海洋生产力带来的海洋直接产出价值6.9万亿美元，而海洋吸收碳的能力价值4.3万亿美元。气候变化如何影响这些角色的不确定性仍然很大，需要进行科学和经济评估，对科学和社会都提出了紧迫的挑战。

Climate change is threatening two key ecosystem services provided by the ocean for humankind: food and storage of atmospheric carbon. The polar regions are major influences on both but are also experiencing the most dramatic and rapid changes. A better understanding of the factors affecting how nutrients are supplied and biologically processed in the ocean is needed to assess the future risk to quantify the dependence of the Earth system, and humanity, on this essential global function that supports global productivity and fisheries. Key nutrients, such as nitrogen (N) and phosphorus (P), are not evenly distributed across the global ocean but are in excess in the polar regions from where they are exported to lower latitudes by ocean circulation. Living matter is produced through combining N, P and carbon (C) (and other minor elements) in a ratio that is more or less the same in most regions of the global ocean. However, the ratios found in the polar regions are substantially different. This is because, firstly, polar nutrients come from a diversity of sources (glaciers, sea-ice, rivers and other seas). Secondly, the polar ecosystem processes these nutrients and carbon in distinct ways. This results in i) a nutrient surplus, which is exported from the polar oceans and supports productivity globally, and ii) the transport of carbon from the atmosphere into deep waters distant from the atmosphere. The pressing issue is that rapid climatic change at the poles is changing both the supply of nutrients and the processing capacity of their ecosystems. This threatens not only the marine food stocks on which humanity depends but also the biological drawdown of C in the oceans, a critical regulator of global climate. Our ability to fully characterise and predict this threat is limited by inadequate representation of polar biogeochemical and ecosystem processes in Earth System Models (ESMs). BIOPOLE represents and links together many of the major environmental research institutes in the UK, who will work with national and international partners to address this problem. We propose an ambitious combination of focussed observations, novel analyses and computer simulations to radically improve our ability to measure, understand and predict how nutrient supply and C storage in the polar regions will be affected by climate change. BIOPOLE will further identify and quantify the wider global impacts to ocean productivity and fisheries. We will sample and collect data at both poles to take a full Earth system perspective of this problem. The latest experimental and observational techniques will delineate C and nutrient processing by the unique polar communities. It will include the use of novel autonomous technologies to collect data over longer periods and greater areas than can be achieved by ships alone. Global modelling will be informed by the new understanding generated and used alongside other modelling approaches to better quantify the role that polar oceans play in sustaining global oceanic primary productivity and fish stocks, and to predict future trends. Climate change is proceeding faster at the poles than any other region, resulting in sea-ice loss and glacial melting. There is a clear urgency in understanding the full biogeochemical and ecosystem level implications of these changes for the polar regions themselves and for the wider Earth system. As ice retreats, the fragile and globally significant ecosystems that are exposed require international protection, which depends on building a strong body of scientific evidence through co-ordinated polar science. Direct outputs from the ocean resulting from ocean productivity have been valued at $6.9trn, while that of the capacity of the oceans to absorb C is $4.3trn. The uncertainty in how climate change will impact these roles remains large, requiring both scientific and economic evaluation, and presenting a pressing challenge for both science and society.