Logic is not always correct.
Well, it is certainly better than its alternative; of that any rational person must be certain.
However, it is logical that the heat Earth contains by itself is entropic; it is breaking down.
So some internal mechanism is causing us to over heat?
That means that if Earth is warming, the other source must be why. If the sun cycles then it is perfectly reasonable to think Earth's warmth cycles similarly. However, the latest warming cycle has had a faster onset than previous others. It is also lasting longer than the previous ones. Now, with that in mind, what has changed? The sun's output? No.
The earth isn't the only solar body that is heating up, so yes! the sun must be heating up. You're right too, it is a natural cycle.
What's left is that Earth is retaining more of the heat faster than it used to. Why? What has changed? The content of the atmosphere has changed.
Think of some other occurrences. EG, pH balances in the ocean are dropping. Why? Crap from the atmosphere is why.
If one follows the evidence, it is pretty clear and does not take faith of any sort.
The atmosphere acts as a blanket and does retain heat. Carbon does trap heat. Non of these facts are in doubt.
What is in doubt is that they, in and of themselves, are the reason for planetary warming. That mankind's paltry 0.24% contribution to global carbon or Al Gores retarded conclusion that if carbon saturation continues planatary warming will too (a big fail), or, THAT ANY OF THIS HAS ANYTHING TO DO WITH THE OTHER BODIES IN THE SOLAR SYSTEM WARMING UP!!!
So the big question, does car exhaust cause global warming? The answer must be no. In fact it doesn't even contribute. The sun is our source of heat therefore the warming energy comes from the sun. If that is true then we could expect other solar bodies too would be warming up - oh wait, they are!!!
It is both absurd and ridiculous to think what we drive could possibly affect the sun. The whole AGW debate is simply preposterous. It is asinine, it is a scam, it is irrational and it is foolishness.
The whole AGW debate has proved to me that the age of reason is over. We have gone back to the "science" of the middle-ages whereby people try and rationalize their beliefs.