The greenhouse theory is bogus. It defies the second law of thermodynamics and has nothing at all to do with venus. Venus is hotter than the earth first and foremost because it is closer to the sun. Second, the atmosphere on venus is about 90 times more dense than the atmosphere of the earth.
Here is a small experiment that you can do yourself to see for yourself that the greenhouse effect with regard to atmosphere is just so much "hot air". If you have a greenhouse great, if you don't use your car. The experiment won't hurt anything. Get yourself a tank of CO2 or any other gas you care to try alone or in combiniation with any other gas.
On a bright sunny day, with either your greenhouse or your car completely closed, take a temperature reading inside. Then using a hose, pump the gas of your choice into the car until you have whatever percentage you choose upto and including 100%. Wait a while and then take another temperature reading. You will see that it hasn't chaged as a result of the nature of the atmosphere. The second law of thermodynamics predicts this.
Now, if you were able to pressurize the interior of your greenhouse considerably above the normal 14 psi, you would see an increase in temperature regardless of what gas or combination of gasses you had in your car. The second law of thermodynamics also predicts this.
The greenhouse effect as described by proponents of anthropogenic global warming is nothing more and nothing less than fear mongering based on grossly misinterpreted science.
