* *注:这种反应是没有引用。以后我会尽量添加它们。* * < br >没有明确的答案。然而,有很多猜测。不管原因是什么,地球是明显无效的碳比金星。的CO 2 <子> < /订阅>金星大气中对应于一个0.88公里厚层碳酸盐岩。地球的岩石圈(岩石圈+海洋大气)集体包含大约一半的碳量,几乎所有被关在岩石层。金星大气中大量的碳和碳在地球大气层的缺乏是主要的因素,区分这两个大气压。行星形成* *。末的假说有关地球是大碰撞假说的形成。 Multiple simulations suggest that this collision had to be rather oblique. An oblique collision between a Mars-sized body and a not-quite Earth-sized body would have drastically changed the Earth's rotation rate prior to and after that collision. If the Earth was rotating very fast prior to the collision, that fast rotation combined with the collision could have resulted in the Earth losing a large chunk of its primordial atmosphere. Venus does not have a large Moon. That suggests that it's formation was a bit less tumultuous than the formation of the Earth. With no big collision to eject that primordial atmosphere, Venus may well have been operating in runaway greenhouse mode from the very onset. *Water.* Whether Venus first had free water on its surface or in its atmosphere has long been a subject of debate. Venus is now nearly devoid of water. If water was present in Venus early atmosphere, it would have served to even more strongly magnify the already huge greenhouse effect of a thick atmosphere that is opaque in the thermal infrared frequencies. If the very young Venus did have liquid water on its surface, it wouldn't have lasted very long. *Plate tectonics.* One of the consequences of a very thick atmosphere and no liquid water is no plate tectonics. Venus has a very thick greenhouse atmosphere, which makes for a very hot surface. The high temperature of Venus's surface means the surface healed itself too rapidly. Plates couldn't form on Venus (Bercovici 2014). Water is an important lubricant for plate tectonics, particularly for subduction (Mian 1990). (But also see (Fei 2013) for an opposing view.) With no plate tectonics, there was no mechanism to bury carbon inside of Venus. Plate tectonics developed fairly early on in Earth's history. By the time the Sun became hot enough (the early Sun was faint), the Earth had already started the process of sequestering away carbon into the lithosphere. *Life.* Life loves carbon. It is one of the key agents by which atmospheric carbon is transferred to the lithosphere. Life apparently never had a chance on Venus. **References** [Bercovici D. and Ricard Y., "Plate tectonics, damage and inheritance," *Nature* 508, 513-516 (2014)](http://www.nature.com/nature/journal/v508/n7497/full/nature13072.html) [Fei et al., "Small effect of water on upper-mantle rheology based on silicon self-diffusion coefficients," *Nature* 498, 213–215 (2013)](http://www.nature.com/nature/journal/v498/n7453/abs/nature12193.html) [Mian Z. and Tozer D., "No water, no plate tectonics: convective heat transfer and the planetary surfaces of Venus and Earth," *Terra Nova* 2:5, 455-459 (1990)](http://onlinelibrary.wiley.com/doi/10.1111/j.1365-3121.1990.tb00102.x/abstract)