I read an article the other day about Venus where it was called Earth’s evil twin. In the same article runaway global warming was mentioned as the reason for the incredibly horrible, windy, acidic, hot surface of the planet.
Now look at Venus. It has no magnetic field. It has no oceans. It has no plate tectonics. It rotates very slowly and it rotates in reverse compared to Earth. Its atmosphere is ninety-two times as dense as Earth’s atmosphere and is 96% carbon dioxide. Let me put that in perspective. Venus has more than two hundred thousand times as much carbon dioxide as earth. We could double our carbon dioxide (to .08%) and it would still be nothing compared to Venus.
The carbon dioxide in the atmosphere of Venus bounces nearly all the sunlight falling on Venus back into space. This is what makes Venus such a bright and beautiful sight in the sky. However, the carbon dioxide may also be acting as a blanket, trapping any heat that is on the surface. Here it may be important to mention that the entire planet is supposed to have been resurfaced half a billion years ago through overwhelming volcanic action. The surface is still hot and it is worth asking if volcanism is the cause and the insulating effect of carbon dioxide has retarded the cooling process.
The winds on Venus circle the planet in three to five days, traveling at two or three hundred miles per hour. No one has a model that explains these winds yet.
Venus was formed at the same time as Earth but in many other ways “twin” is a really unhelpful way to think about it. It has a unique history that we don’t fully understand and comparing Earth to Venus is not really helpful for understanding where we are headed.