气候敏感性受到过去4.2亿年的二氧化碳度的限制
Dana L Royer1, Robert A Berner, Jeffrey Park
1Department of Earth and Environmental Sciences, Wesleyan University, Middletown, Connecticut 06459, USA. droyer@wesleyan.edu
Nature
|March 30, 2007
概括
气候敏感性,即由于大气二氧化碳增加了一倍而导致地球温度上升,在4亿2000万年中可能超过1.5°C. 这种长期前景证实了二氧化碳对全球温度的重大影响.
科学领域:
- 古气候学 古气候学
- 气候建模 气候建模
- 地球系统科学 地球系统科学
背景情况:
- 了解气候敏感性对于解释过去气候变化和预测未来气候变化至关重要.
- 目前的估计通常依赖于短期数据,可能低估了长期气候变化.
- 之前的研究表明气候敏感度范围在1.5至6.2°C之间,但存在不一致性.
研究的目的:
- 为了估计过去4.2亿年的长期平衡气候敏感性.
- 评估跨地质时间尺度的气候敏感性强度.
- 为了评估二氧化碳在数百万年时间内的辐射强迫作用.
主要方法:
- 在过去4.2亿年的大气二氧化碳度建模.
- 将模型输出与古气候代理记录进行比较.
- 分析不同地质时代的气候敏感性.
主要成果:
- 估计的长期气候敏感性与短期估计基本一致.
- 在数百万年的时间尺度上,二氧化碳的弱辐射强迫是极不可能的.
- 超过1.5°C的气候敏感性似乎是4亿2000万年来地球气候系统的一个稳定的特征.
结论:
- 地球的气候系统对二氧化碳在地质时间上的强迫表现出强烈的敏感性.
- 长期气候敏感度估计为了解未来气候变化提供了关键的背景.
- 这些发现挑战了对气候敏感性在广大时间范围内显著变化的假设.
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