Global warming is just a theory. It’s not a proven fact. Scientists have some fancy computer models and such, but I think it’s safe to say that they don’t undestand the complex workings of our climate to say for certain (otherwise we’d get more accurate weather predictions). For most of its life, earth was much warmer than it is now. What we call global warming could be a return to a more normal climate as far as the earth is concerned, or it could be a slight variation like those that have occurred many times in the past.
However, if you look at the temperature of the earth over the time period that we’ve kept track of temperature, it goes up rather suspiciously hand in hand with the amount of crap that we are throwing up into the atmosphere.
The OP is correct though. It’s just a theory at this point. It’s pretty likely to be true, but it’s far from proven. I don’t think it can be proven or disproven until we understand how the earth works a little bit better. It’s a lot like smoking and lung cancer. We’re pretty sure that we see cause and effect, but it’s hard to prove it in court because we don’t understand the mechanisms involved. As far as the OP is concerned though, simply understanding how the earth works and what is actually causing the warming, and being able to accurately predict temperature swings and all sorts of other stuff (which is what scientists are trying to do) would probably be enough to sufficiently prove or disprove humans as the root cause. I don’t see how a “control” earth would be necessary.
I got into an argument with a co-worker one day at lunch by saying that global warming isn’t necessarily a bad thing. If it gets hot and moist much of the earth will be a tropical paradise, like it was during the times of the dinosaurs. It’s only if it gets hot and dry that things could get bad. Then you could have things like skyrocketing food prices, food shortages and mass starvation, and all sorts of bad things.