Geothermal is not good for global warming bc it is an additional source of energy which would normally be contained. The sun gives such amount of wattage and the earth can give so much wattage back to the universe. Nuclear, geothermal and fusion is stored energy like fossil fuel which adds to the heat in the atmosphere. Today that only amounts to 5% of global warming but if it's the only source of energy it could add more. CO2 is the focus right now bc it is continuous warming potential but the other energy forms have it too. Wind and solar is just "saving" sun energy from being instantly converted into heat and can be so used for our pleasure as it doesn't add to the input/output equation.
Heat waste is absolutely miniscule compared to the amount of energy the Earth receives from the Sun. As in, the Earth is continuously bombarded by 173 petawatts of solar radiation. So you can see why it would be worth trading some waste heat to reduce the retention of solar energy in the atmosphere.
This doesn't make too much sense in this case, the geothermal energy is being stored in chemical bonds in the carbon sequestration process and returned underground