Venus Was Potentially Habitable (until a mysterious event happened)

Summary

September 20, 2019: CNN article reports that scientists now believe Venus was potentially habitable for billions of years. Advanced climate simulations suggest that Venus had stable oceans, a temperate climate, and an atmosphere not terribly unlike our own until about 700 million to 750 million years ago, when some unknown event, probably volcanic in origin, released large amounts of carbon dioxide from the planet's crust into the air and started run-away global warming and a drastic thickening of the atmosphere.

Prior to the big event, storm clouds would have been enough to (deflect the excess sunlight that hits Venus and) keep the planet habitable / cool.

Source

Bibliography

1. Original Article at CNN

Game and Story Use

• This means a precursor civilization could be hidden as close as the next planet inward, buried beneath the hot fog.
  • Even if there isn't a lost civilization there, there could be fossilized remains or some sort of extremophile life hanging on tenaciously.
  • 700 million + years is a long time for things to corrode, biodegrade, or melt under all that heat and pressure, so there may not be anything left of such a civilization. But if they were intelligent and advanced enough, they may have been able to survive for a long time as things went pear-shaped. Knowing they were doomed, they may have created a time capsule or vault that would survive the eventual fate of the planet. Something like the Raven Rock Mountain Complex or Georgia Guidestones could still be there after the end.
• The current appearance and chemical composition of Venus could be used as a "roadmap" for what the earth may look like in some distance future where mankind fled a dying planet and spread out to the stars.
  • Of course, if we develop the terraforming technology to colonize other worlds, it makes you wonder why we wouldn't also save the Earth from such a fate, but you can probably hand wave that away with politics or some other disaster.