A few billion years ago, Venus had a collision with something that turned it on its side and slowed its rotation way down. One day on Venus is almost six Earth months long.

Because of Venus’ proximity to the Sun and its very long afternoons, it never developed oceans. Because it never developed oceans, it has a huge amount of CO2 in its atmosphere. (On Earth most of the CO2 is trapped in limestone, which forms in water.)

The very large amount of CO2 in Venus’ atmosphere has created very high surface pressures, which causes very high temperatures. PV = nRT

The difference between Earth and Venus is that we have oceans, which allowed limestone to form, and keeps our atmospheric pressure down to 1/100th of that on Venus. Thus Earth is much cooler.

Hansen got his PhD for writing a completely nonsensical theory about Venus heat. My dissertation took five minutes. Can I have my Columbia PhD now?