A system captures carbon dioxide from a flue gas of a power generation facility by using cold heat of liquefied natural gas and utilizes the captured carbon dioxide for mining natural gas, using heat of the flue gas to regasify the LNG. Solidified dry ice is captured from gaseous carbon dioxide contained in the flue gas, and the captured dry ice is used as filler when mining natural gas. The system includes a mining facility, a vehicle to transport LNG liquefied by the mining facility; and a facility for regasifying the transported LNG and capturing dry ice from the carbon dioxide. In the regasification and capture facility, the flue gas exchanges heat with the LNG, thereby regasifying the LNG at an increased temperature and capturing the dry ice from the carbon dioxide. The captured dry ice is transported to the mining facility, which uses it for mining the natural gas.