摘要
政府间气候变化专门委员会(IPCC)于2021年8月发布了第六次评估报告第一工作组报告《气候变化2021:自然科学基础》。该报告基于最新的观测和模拟研究,评估了冰冻圈变化的现状,并采用CMIP6模式对未来变化进行了预估。报告明确指出,近十多年来冰冻圈呈现加速萎缩状态:北极海冰面积显著减小、厚度减薄、冰量迅速减少;格陵兰冰盖、南极冰盖和全球山地冰川物质亏损加剧;多年冻土温度升高、活动层增厚,海底多年冻土范围减少;北半球积雪范围也在明显变小,但积雪量有较大空间差异。冰冻圈的快速萎缩加速海平面的上升。未来人类活动对冰冻圈萎缩的影响将愈加显著,从而导致北极海冰面积继续减少乃至消失,冰盖和冰川物质将持续亏损,多年冻土和积雪的范围继续缩减。报告也提出,目前冰冻圈研究仍存在观测资料稀缺、模型对各影响因素的敏感性参数和过程描述亟需提升、对吸光性杂质的变化机制认知不足等问题,从而影响了对冰冻圈变化预估的准确性,未来需要重点关注。
The Working Group I report of the Sixth Assessment Report(AR6)of the Intergovernmental Panel on Climate Change(IPCC)was released in August2021. Base on updated and expanding data,AR6 presented the improved assessment of past changes and processes of cryosphere. AR6 also predicted the future changes using the models in CMIP6. The components of cryosphere were rapid shrinking under climate warming in the last decade. There were decreasing trends in Arctic sea-ice area and thickness. Sea-ice loss was significant. The Greenland Ice Sheet,the Antarctic Ice Sheet and all glaciers lost more mass than in any other decade. Global warming over the last decades had led to widespread permafrost warming,active layer thickness increasing and subsea permafrost extent reducing. Snow cover extent in the Northern Hemisphere also decreased significantly.However,the variations of snow depth and snow water equivalent showed great spatial heterogeneity. The rapid shrinking of the cryosphere accelerated the global mean sea level rise. The impact of human activities on cryosphere will become more significant in the future. The Arctic sea-ice area will decrease,and the Arctic Ocean will likely become practically sea ice-free. The Greenland Ice Sheet,the Antarctic Ice Sheet and glaciers will continue to lose mass throughout this century. Permafrost and Northern Hemisphere snow cover extent will continue to decrease as global climate continues to warm. In addition,there are still uncertainties in the prediction of cryosphere due to the absence of observations,the poor sensitivity of models to the components and processes of cryosphere,and the inexplicit represent of the mechanism of light-absorbing impurities. More attentions should be paid on these issues in the future.
作者
钟歆玥
康世昌
郭万钦
吴晓东
陈金雷
ZHONG Xinyue;KANG Shichang;GUO Wanqin;WU Xiaodong;CHEN Jinlei(Key Laboratory of Remote Sensing of Gansu Province,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;State Key Laboratory of Cryospheric Science,Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China)
出处
《冰川冻土》
CSCD
北大核心
2022年第3期946-953,共8页
Journal of Glaciology and Geocryology
基金
中国科学院国际伙伴计划“北极冰冻圈变化与可持续发展国际大科学计划”(131B62KYSB20180003)
冰冻圈科学国家重点实验室自主课题(SKLCS-ZZ-2021)资助。