Routes to global glaciation
Routes to global glaciation
复制标题
全球冰川作用的路线
DOI：
10.1098/rspa.2020.0303
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
D. Rothman
中科院分区：
文献类型：
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作者：
Constantin W. Arnscheidt;D. Rothman
理论和观测表明，当太阳加热或碳循环的变化超过临界阈值时，地球和类地行星可能会经历失控的低纬度冰川作用。在这里，我们使用冰-反照率反馈和碳酸盐-硅酸盐循环的简单动力系统表示来表明，当太阳加热变化快于临界速率时，也会触发冰川作用。这种“速率引起的冰川”仍然可以在远离宜居区外缘的地方进行，因为温暖的气候状态保持了长期稳定。相比之下，碳循环变化引起的冰川作用需要温暖的气候状态变得不稳定，从而限制了可能在地球过去引起全球冰川作用的扰动类型。我们证明，当地球气候在两个温暖稳定状态之间转变时，就会发生冰川作用。地球系统的这一特性有助于解释为什么生命发展中的重大事件都伴随着冰川作用。
Theory and observation suggest that Earth and Earth-like planets can undergo runaway low-latitude glaciation when changes in solar heating or in the carbon cycle exceed a critical threshold. Here, we use a simple dynamical-system representation of the ice–albedo feedback and the carbonate–silicate cycle to show that glaciation is also triggered when solar heating changes faster than a critical rate. Such ‘rate-induced glaciations’ remain accessible far from the outer edge of the habitable zone, because the warm climate state retains long-term stability. In contrast, glaciations induced by changes in the carbon cycle require the warm climate state to become unstable, constraining the kinds of perturbations that could have caused global glaciation in Earth’s past. We show that glaciations can occur when Earth’s climate transitions between two warm stable states; this property of the Earth system could help explain why major events in the development of life have been accompanied by glaciations.