Can you explain what you mean by fallacy?  What makes you think that accumulation of GHGs in the atmosphere doesn't cause the climate to change?

Cap-and-trade systems are simple: There are a certain number of emission allowances.  The number decreases as the regulatory body ratchets down the allowed emissions.  These allowances have a value based on the number of entities involved in the program and the amount they admit.  If they purchase an allowance but can reduce their emissions equal to the amount equivalent to that allowance, they can sell that allowance at whatever the price of market dictates.  This was devised by conservative think tanks, not by liberal ivory towers.