DOI: 10.1038/ngeo2914
论文题名: A lower limit to atmospheric CO 2 concentrations over the past 800,000 years
作者: Galbraith E.D. ; Eggleston S.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2017
卷: 10, 期: 4 起始页码: 295
结束页码: 298
语种: 英语
Scopus关键词: carbon dioxide
; climate feedback
; concentration (composition)
; cooling
; glacial-interglacial cycle
; ice sheet
; orbital forcing
; temperature
; volume
; Antarctic Ice Sheet
; Antarctica
英文摘要: Global temperatures and atmospheric CO 2 concentrations varied widely over the glacial cycles of the past 800,000 years. But despite this variability, Antarctic ice cores have shown that CO 2 concentrations were very similar during all the coldest points of these cycles. Remarkably, the recurring minimum CO 2 concentrations (190±7 ppm) fall on the lower bound of any known in Earth history. Here we show that although the volume of terrestrial ice sheets was normally distributed over the past 800,000 years, as might be expected from the approximately normal distribution of the orbital forcing that drove the glacial cycles, Antarctic temperatures have a strong cold mode, whereas CO 2 concentrations have both a cold mode and a central mode. Although multiple explanations are possible, the recurring CO 2 minima and pronounced cold modes are consistent with a strong negative feedback to decreasing CO 2 that resisted further cooling on timescales shorter than 10,000 years. We suggest that one possible negative feedback is CO 2 -limitation of photosynthesis, either directly or via CO 2 -limitation of N 2 fixation, which could have inhibited further lowering of CO 2 by reducing carbon storage. © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/105797
Appears in Collections: 气候减缓与适应 科学计划与规划
There are no files associated with this item.
作者单位: ICREA, Pg. Lluís Companys 23, Barcelona, Spain; Institut de Ciència i Tecnologia Ambientals (ICTA), Department of Mathematics, Universitat Autònoma de Barcelona, Barcelona, Spain; Department of Earth and Planetary Science, McGill University, Montreal, QC, Canada
Recommended Citation:
Galbraith E.D.,Eggleston S.. A lower limit to atmospheric CO 2 concentrations over the past 800,000 years[J]. Nature Geoscience,2017-01-01,10(4)