[mcv]

Global warming doesn't come from heat from the ground, but from the atmosphere absorbing extra heat from the sun due to the increased amount of CO2 in it. If this geothermal energy generates enough power so we burn less fossil fuels put less CO2 into the atmosphere, it will slow global warming. The amount of heat we'd get from the ground would be comparable to the amount of heat we get from burning fossil fuels, and both would be negligible compared to the amount of additional heat we get from the sun.