Don,
The fact of the matter is that we are adding NEW gases to the atmosphere by taking carbon and other fossil fuels in solid or liquid form, and turning them into a gas.
Obviously when you add more greenhouse gases, the greenhouse gas effect will be more prominent.
Planting more trees isn't really the solution to taking gases out of the air.... Because it mainly just converts a greenhouse gas "carbon dioxide" to another greenhouse gas "oxygen". Trees still are a solution because they can be turned back into fossil fuels over the course of a long time... Thus, reducing the amount of greenhouse gases in the air.
What needs to happen is we have to take the gases and take them out of the system, that is, turn them back into liquid/solid so that there's fewer greenhouse gases.
It will probably take tens out thousands of years to reset the greenhouse gas levels back to where they were before. When the dinosaurs lived, the surface temperature of the earth was much higher (I think about 60 C average), because the greenhouse gases that are now locked away in fossil fuels were in the atmosphere then. If we were to pump all the fossil fuels out and burn them, we'd reach a similar temperature on earth that it was in the dinosaur age.
I'm not a scientist and don't have any major degrees yet, but not many people here have climatology degrees either. A biology degree doesn't qualify you to discuss climatology. They're two very different things. My argument is simply based on logic.
Yet, even though I may not be an expert on this subject, I can tell you that 97% of experts from various parts of the world DO agree that it is occurring, I will be more inclined to agree with the majority of scientists.