全球气温上升的另一个重要影响是以冰的融化形式对冰冻圈造成的，尤其是在两极。Sigmond等人(2018年，p.1)的分析表明，1.5°C和2°C的升温之间的差异相当于一个无冰的北极，从“每5年一次到每40年一次”。正如之前所讨论的，融化的冰导致了GMSL的上升，威胁着全球人口，也扰乱了水文循环。此外，进一步的融化会形成一个正反馈循环，因为融化的冰水比冰的反照率低，所以会吸收更多的辐射，导致进一步的变暖。淡水从融化的冰原流入，特别是在北半球影响温盐环流，并被认为是削弱湾流(Skinner & Murck, 2011)。温盐环流停止的重要性具有全球影响;因为它缓和了欧洲的气候，温度可以降低5°C (Vellinga & Wood, 2008)。如果这种降温效果仅比工业化前水平高出1摄氏度，就会对全球产生严重影响。到2100年，世界GDP将减少0.08% (Tol)。,2002)。此外，Link & Tol(2004)认为，可能会出现广泛的疾病和其他健康问题，导致大量人口从欧洲向外迁移。由于这些结果只模拟了1°C的上升，如果要避免这种后果，全球变暖必须不超过工业化前的1.5°C。Niederdrenk & Notz(2018)得出结论，北极地区9月无冰的气温极有可能上升1.7摄氏度或更高。因此，1.5°C的目标将确保北极全年保持冰层覆盖。然而，其他证据表明，淡水从格陵兰岛流入北大西洋，作为一种机制，抵消了融化的冰减少的反照率所引起的正反馈，并帮助系统恢复稳定状态。这种效应对未来温度升高的影响程度根据所使用的模型而不同(Palter et al.， 2018)。因此，目前还不清楚北半球的高温如何有助于这种“区域稳定效应”(Palter et al.， 2018, p. 823)。
加拿大地理paper代写 冰冻圈
Another key impact of rising global temperatures is on the cryosphere in the form of melting ice, particularly at the poles. Analysis by Sigmond et al. (2018, p.1) suggest the difference between a 1.5°C and 2°C increase in temperature equates to an ice-free Arctic from “once in every five to once in every forty years”. The melted ice contributes to GMSL rise, which as previously discussed, threatens human populations globally, as well as disrupting the hydrologic cycle. Additionally, further melting creates a positive feedback loop as melted ice water has a lower albedo than ice, so absorbs more radiation, inducing further warming. The freshwater influx from melting ice sheets, particularly in the Northern Hemisphere affects the thermohaline circulation, and is thought to be weakening the Gulf Stream (Skinner & Murck, 2011). The significance of a thermohaline circulation shutdown has a global impact; because it moderates European climate, temperatures could reduce by 5°C (Vellinga & Wood, 2008). If this cooling effect were limited to just 1°C increase above pre-industrial levels, it would have a serious global impact. For primary industry, increased crop-failure would likely occur and by 2100, world GDP could be reduced by up to 0.08% (Tol., 2002). Furthermore, Link & Tol (2004) suggest widespread disease and other health issues may arise, resulting in a large outmigration from Europe. As these results were only modelled for a 1°C rise only, it is imperative that global warming should not exceed 1.5°C of pre-industrial conditions if such consequences are to be avoided.Niederdrenk & Notz (2018) conclude that ice-free Septembers in the Arctic are highly likely for rises of 1.7°C and above. Therefore, the target of 1.5°C would ensure the Arctic maintains its ice-cover year-round. However, other evidence suggests that freshwater influx from Greenland into the northern Atlantic Ocean acts as a mechanism to offset the positive feedback induced by the melting ice’s reduced albedo and to help the system return to a steady-state. The extent of this effect on future temperature increases varies according to the model being used (Palter et al., 2018). Therefore, it is unclear how higher temperatures in the Northern Hemisphere could contribute to this “regional stabilizing effect” (Palter et al., 2018, p. 823).
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