Surface life has been argued to be crucial in keeping a planet habitable in the long term. Biologically enhanced weathering compensates for increasing solar luminosity, and temperature‐dependent plant productivity weakens climate perturbations. Furthermore, a reduced calcification rate of marine organisms provides a negative feedback to rising atmospheric CO₂. Here, I present a model of the long‐term carbon cycle including biological enhancement of weathering and marine calcification. Climate oscillations of periods from thousands to millions of years arise from a simple model of mountain uplift and erosion. I systematically study the influence of the biologically driven feedbacks on damping these oscillations. For oscillations of periods <2 Myr, the marine calcification feedback yields surface temperature amplitudes that are approximately 1/3 lower compared to a model that ignores this feedback. Abiotic oceans, however, would not necessarily imply a less stable climate on short timescales, due to a higher pH and thereby a higher buffer capacity. On longer timescales, the higher ocean pH would reduce climate stability, since the seafloor weathering feedback would work less efficiently. Biological enhancement of weathering helps stabilizing the climate against oscillations of periods >0.5 Myr. These findings are sensitive to the ratio of land to oceans, however. Furthermore, the mantle carbon degassing rate plays a role, since the temperature dependence of biological primary productivity may be smaller at higher temperatures. Altogether, life can be argued to stabilize the climate on timescales longer than some 100 kyr, while details depend on the geological state of the planet.

中文翻译：

---

在不同时间范围内生命对气候稳定的影响

有人认为，地表寿命对于使行星长期保持宜居性至关重要。生物增强的风化作用补偿了日光亮度的增加，而温度依赖性的植物生产力减弱了气候扰动。此外，降低的海洋生物钙化速率为大气CO _2的上升提供了负面反馈。在这里，我提出了一个长期碳循环的模型，其中包括风化和海洋钙化的生物增强。一个简单的山隆起和侵蚀模型就产生了数千年到数百万年的气候振荡。我系统地研究了生物驱动反馈对阻尼这些振荡的影响。对于周期的振荡<2 Myr，与忽略该反馈的模型相比，海洋钙化反馈产生的地表温度幅度大约低1/3。然而，由于较高的pH值和较高的缓冲能力，非生物海洋并不一定意味着在短时间范围内气候不稳定。在较长的时间尺度上，较高的海洋pH值将降低气候稳定性，因为海底风化反馈的效率较低。风化的生物增强有助于稳定气候，防止周期振荡>0.5马币 但是，这些发现对陆地与海洋的比例很敏感。此外，地幔碳的脱气速率也起着作用，因为在较高的温度下，生物初级生产力的温度依赖性可能较小。总而言之，可以说生命可以使气候稳定在比大约100 kyr长的时间尺度上，而细节取决于地球的地质状态。