Volcanology of Venus
The surface of Venus is dominated by volcanic features and has more volcanoes than any other planet in the Solar System. It has a surface that is 90% basalt, and about 65% of the planet consists of a mosaic of volcanic lava plains, indicating that volcanism played a major role in shaping its surface. There are more than 1,000 volcanic structures and possible periodic resurfacing of Venus by floods of lava. The planet may have had a major global resurfacing event about 500 million years ago, from what scientists can tell from the density of impact craters on the surface. Venus has an atmosphere rich in carbon dioxide, with a density that is 90 times greater than Earth's atmosphere.
Carbon capture and storage
Terraforming the planet Venus by removing CO from the atmosphere was first scholarly proposed by the astronomer Carl Sagan in 1961, although fictional treatments, such as "The Big Rain" of The Psychotechnic League by novelist Poul Anderson, preceded it. Adjustments to the existing environment of Venus to support human life would require at least three major changes to the planet's atmosphere: Reducing Venus's surface temperature of , eliminating most of the planet's dense carbon dioxide and sulfur dioxide atmosphere via removal or conversion to some other form, and the addition of breathable oxygen to the atmosphere. These three changes are closely interrelated, because Venus's extreme temperature is due to the high pressure of its dense atmosphere, and the greenhouse effect.