Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305, USA.
Science. 2014 Mar 28;343(6178):1502-4. doi: 10.1126/science.1250770. Epub 2014 Mar 13.
Earth's temperature is thought to be regulated by a negative feedback between atmospheric CO2 levels and chemical weathering of silicate rocks that operates over million-year time scales. To explain variations in the strength of the weathering feedback, we present a model for silicate weathering that regulates climatic and tectonic forcing through hydrologic processes and imposes a thermodynamic limit on weathering fluxes, based on the physical and chemical properties of river basins. Climate regulation by silicate weathering is thus strongest when global topography is elevated, similar to the situation today, and lowest when global topography is more subdued, allowing planetary temperatures to vary depending on the global distribution of topography and mountain belts, even in the absence of appreciable changes in CO2 degassing rates.
据认为，地球的温度是通过大气 CO2 水平与硅酸盐岩石的化学风化之间的负反馈来调节的，这种反馈作用在百万年的时间尺度上。为了解释风化反馈的强度变化，我们提出了一个硅酸盐风化模型，该模型通过水文过程来调节气候和构造强迫，并根据河流流域的物理和化学性质对风化通量施加热力学限制。因此，当全球地形升高时，硅酸盐风化的气候调节作用最强，类似于今天的情况，而当全球地形更加平缓时，硅酸盐风化的气候调节作用最弱，这使得行星温度可以根据地形和山脉带的全球分布而变化，即使在 CO2 释放率没有明显变化的情况下也是如此。
