The nearly logarithmic radiative impact of CO₂ means that planets near the outer edge of the liquid water habitable zone (HZ) require ∼10⁶ × more CO₂ to maintain temperatures that are conducive to standing liquid water on the planetary surface than their counterparts near the inner edge. This logarithmic radiative response also means that atmospheric CO₂ changes of a given mass will have smaller temperature effects on higher pCO₂ planets. Ocean pH is linked to atmospheric pCO₂ through seawater carbonate speciation and calcium carbonate dissolution/precipitation, and the response of pH to changes in pCO₂ also decreases at higher initial pCO₂. Here, we use idealized climate and ocean chemistry models to demonstrate that CO₂ perturbations large enough to cause catastrophic changes to surface temperature and ocean pH on temperate, low-pCO₂ planets in the innermost region of the HZ are likely to have much smaller effects on planets with higher pCO₂, as may be the case for terrestrial planets with active carbonate-silicate cycles receiving less instellation than the Earth. Major bouts of extraterrestrial fossil fuel combustion or volcanic CO₂ outgassing on high-pCO₂ planets in the mid-to-outer HZ should have mild or negligible impacts on surface temperature and ocean pH. Owing to low pCO₂, Phanerozoic Earth's surface environment may be unusually volatile compared with similar planets receiving lower instellation.

中文翻译：

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高 pCO2 降低了大部分宜居带温带类地行星对 CO2 扰动的敏感性

CO ₂的近对数辐射影响意味着靠近液态水宜居带 (HZ) 外边缘的行星需要大约 10 ⁶ 倍的 CO ₂来维持有利于行星表面液态水存在的温度，而不是附近的行星。内边缘。这种对数辐射响应也意味着给定质量的大气 CO ₂变化对较高 pCO ₂行星的温度影响较小。海洋 pH 值通过海水碳酸盐形态和碳酸钙溶解/沉淀与大气 pCO ₂相关，并且 pH 值对 pCO ₂变化的响应在初始 pCO ₂较高时也会降低. 在这里，我们使用理想化的气候和海洋化学模型来证明，足够大的CO ₂扰动足以导致HZ 最内层温带、低 pCO ₂行星的表面温度和海洋 pH 值发生灾难性变化，其影响可能要小得多在具有较高 pCO _{2 的}行星上，对于具有活跃碳酸盐-硅酸盐循环的类地行星而言，接收星象的数量可能少于地球。外星化石燃料燃烧或火山 CO ₂在中到外 HZ 的高 pCO ₂行星上的主要发作对地表温度和海洋 pH 值的影响应该很小或可以忽略不计。由于 pCO ₂低, 与接收较低星群的类似行星相比，显生宙地球的表面环境可能异常不稳定。