Sensitivity of the West Antarctic Ice Sheet to 2 Degrees Celsius (SWAIS 2C): Did a trans-Antarctic seaway open in a warmer-than-present world?

目前，南极西部冰盖的冰量足以使全球海平面上升5米，如果全部融化的话。来自卫星的信息表明，南极西部冰盖的冰损速度比南极其他任何地区都快。然而，当全球平均气温超过2摄氏度时，南极西部冰盖会融化多少，以及融化速度有多快，目前还不得而知。按照目前二氧化碳排放到大气中的速度，在未来10年和20年内，全球平均气温将分别比工业化前水平高出1.5摄氏度和2.0摄氏度。海平面上升是人类引起的气候变化在全球范围内最明显的信号之一。自1880年以来，全球平均海平面上升了22厘米，并将在21世纪以后继续上升。考虑到南极洲未来对全球海平面上升的影响将产生深远的国际影响，来自9个国家的科学家通过国际合作制定了swis 2C项目，以便更好地预测未来变化的规模和时间。国际swis 2C项目的科学家将收集和研究地质（岩石、沉积物）、冰川学（冰）和地球物理（地球物理性质）数据，并提供新的信息，指导气候和冰盖数值模型的发展，以更好地了解和预测南极洲西部冰盖将如何导致未来海平面上升。该项目旨在解释在地球历史的最近时期，当全球平均温度达到或超过2摄氏度时，西南极洲过去的环境状况（温暖的开放海洋，寒冷的冰雪覆盖的海洋或地面冰盖），预计在未来20年内达到这一水平。这些类型的地质研究将帮助我们了解在过去的温暖时期冰融化的数量和速度，以及涉及的过程。建模研究将利用这些关于过去和现在冰盖行为的新信息，更好地预测南极西部冰盖未来融化的程度和速度。该提案将支持SWAIS 2C项目的德国成员研究过去不同时期沉积的沉积物的化学和物理性质，以确定过去钻探地点的气候和环境条件，以及是否开通了跨南极海道。

The West Antarctic Ice Sheet presently holds enough ice to raise global sea level by up to five meters if it all melted. Information from satellites demonstrates that the West Antarctic Ice Sheet is losing ice faster than any other region in the Antarctic. However, how much of the West Antarctic Ice Sheet will melt and how quickly it will happen when average global temperature exceeds 2 degrees celsius is currently unknown. At the current rate of CO2 emissions to the atmosphere, average global temperatures will be 1.5 degrees celsius and 2.0 degrees celsius above preindustrial levels in 10 and 20 years, respectively. Sea level rise is one of the clearest planet-wide signals of this human-induced climate change. Global mean sea level has increased by ~22 cm since 1880 and will continue to rise well beyond the 21st century. Given the far-reaching and international consequences of Antarctica’s future contribution to global sea level rise, the SWAIS 2C Project was developed through an international collaboration of scientists from nine countries in order to better forecast the size and timing of future changes. The international SWAIS 2C Project scientists will collect and study geological (rocks, sediments), glaciological (ice), and geophysical (Earth physical properties) data and provide new information to guide the development of climate and ice sheet numerical models to better understand and predict how the ice sheet on West Antarctica will contribute to future sea level rise. The project aims to interpret the state of past environmental conditions in West Antarctica (warm open marine seas, cold ice-covered ocean, or grounded ice sheet) during recent periods in Earth’s history when the average global temperature reached or exceeded 2 degrees celsius, a level anticipated within the next two decades. These types of geological studies will help us understand how much and how fast the ice melted during past warm periods and what processes are involved. Modeling studies will use this new information regarding past and present ice sheet behavior to make better predictions of how much and how fast the West Antarctic Ice Sheet will melt in the future. This proposal will support German members of the SWAIS 2C project to study the chemical and physical properties of sediments deposited at different times in the past in order to determine what the climate was like and what environmental conditions prevailed at the drilling site during the past and if a trans-Antarctic seaway opened.