@rosborne979,
That is a false argument rosborne...
Would you argue that brakes won't work to stop a car on a hill because gravity has always worked?
Would you argue that adding water to a glass won't cause it to overflow because there is already water in it?
Would you argue that we can't dam the Colorado because the grand canyon proves it can't be done?
Because warming occurs for other reasons in no way shows that man can't contribute.
1. You ignore science that shows that increasing the amount of CO2 causes gas mixtures to retain heat.
2. You ignore science that shows the output of the sun can't account for all the increase in temperature.
Until you can explain these you are doing nothing more than pointing at the grand canyon as evidence the hoover dam can't exist.