I really hope the scientists have thought about the affect their "fix" will have on the environment. Fair enough the lake is safe now, but perhaps a simple warning system or a permanent evacuation would be the sensible option...
The release system is a natural mechism of the area, and while the solution isn't creating more CO2, it is likely that it is speeding up the release from the underlying chamber. The pressure of the water and gradual buildup of CO2 above would have slowed down the release of the CO2 from the chamber into the water. In theory, now that the pressure has been lowered, the CO2 will be released from the magma chamber at a much higher release rate, lowering the pressure in the chamber and allowing the creation rate of the gas to increase to its highest potential.
The release system is a natural mechism of the area, and while the solution isn't creating more CO2, it is likely that it is speeding up the release from the underlying chamber. The pressure of the water and gradual buildup of CO2 above would have slowed down the release of the CO2 from the chamber into the water. In theory, now that the pressure has been lowered, the CO2 will be released from the magma chamber at a much higher release rate, lowering the pressure in the chamber and allowing the creation rate of the gas to increase to its highest potential.