THE GLOBAL IMPACTS OF POLAR GEOENGINEERING

北极变暖的速度是全球平均水平的两到四倍(Jacobs等人，2021年)，(Masson-Delmotte等人，2021年)，并且在40年内失去了夏末海冰总量的四分之三(Notz&Stroeve，2018年)。海冰反照率的反馈和永久冻土融化释放的温室气体意味着这些变化增加了全球变暖的负担，而极地冰盖的丧失是海平面长期上升的最大贡献因素。太阳地球工程学描述了一套通过反射太阳光来冷却地球的方案。虽然大多数研究都集中在全球应用上，但北极显然是一个区域目标。在这个项目中，我将评估太阳地球工程阻止北极变化，特别是海冰消失的潜力，以及这种干预措施对全球气候的影响，特别是对中纬度极端天气及其驱动因素的变化模式的影响。气象局的哈德利中心气候模型将用于模拟平流层气溶胶地球工程、海洋云增亮和海冰反照率修正的影响。然后将这些模拟与对历史火山喷发的气候反应的观察和模拟进行比较，历史火山喷发是地球工程学的一种自然类比。

The Arctic is warming two to four times faster than the global average (Jacobs et al., 2021), (Masson-Delmotte et al., 2021), and has lost three quarters of its late summer sea ice volume in 40 years (Notz & Stroeve, 2018). The sea-ice albedo feedback and release of greenhouse gases from thawing permafrost mean these changes add to the burden of global warming, and the loss of polar ice sheets is the largest contributor to long-term sea level rise. Solar geoengineering describes a set of proposals to cool the Earth by reflecting away sunlight. While most research has focused on global applications, the Arctic is an obvious regional target. In this project I will assess the potential for solar geoengineering to arrest Arctic changes, especially sea-ice loss, and the implications of such interventions for the global climate, in particular on mid-latitude weather extremes and the modes of variability that drive them. The Met Office's Hadley Centre climate models will be used to simulate the effects of stratospheric aerosol geoengineering, marine cloud brightening, and sea-ice albedo modification. These simulations will then be compared with observations and simulations of the climate response to historical volcanic eruptions, a natural analogue for geoengineering.