The atmosphere of Venus is mostly made of CO2; about 96%. Nitrogen comprises about 3.5% with traces of other gasses such as sulphur dioxide and water vapor. The Venusian atmosphere is 90 times heavier than Earth’s. If N.A.S.A. were to prioritize developing technology to convert the CO2 of Venus into oxygen and perhaps coal it might be a practical way to find solutions for Earth’s atmospheric surplus of CO2 and terraform Venus at the same time.
converting CO2 into energy
single catalyst splits CO2 into CO and O2
Venus is also quite hot. Its greenhouse gas and location a little closer to the sun have made its surface temperature more than 700 degrees fahrenheit. If the temperature can be reduced somewhat is could be possible for botanists to generate some form of exothermal planet that could thrive on Venus and also help convert CO2 into oxygen.
Some people would like to build a floating cloud-town 31 miles above Venus where the temperature would be cooler. Venus is closer to Earth than mars and getting there is easier. Yet converting the CO2 to oxygen and other materials would be a good project for drone and mechanical technology with an oxygenated atmosphere and extremal exothermal engineered plants bringing the entire surface of the world to one more useful for humanity down the road. Venus has more resources than CO2 after all.
If one insisted upon a float on the clouds approach, one might consider covering the planet with floating solar reflecting plates to cool the atmosphere a little. The floats might be used to convert CO2 to oxygen and whatever else-perhaps carbon monoxide and/or coal, and the carbon shaped into gliders to land at some particular place on the planet instead of being scattered all over.
Mars is still a good colony location for people living underground and under glass above. A moon base can serve developments on both worlds and additional planetary locales beyond