Technology is developing at a geometric rate. There is no doubt in my mind whatsoever that we will develop a renewable energy as a permanent solution to the CO2 emissions problem. That said, if the warming problem becomes a crisis that can only be fixed by cooling the earth, we will have options - deploying mirrors/reflective sails in space(sunshade effect), dumping iron filings in the ocean to increase CO2 absorbing plankton, even discharging sulfer in the atmosphere(same effect as Mt Pinatubo erruption in 91 that cooled the earth by 1/2 degree...sulfer absorbs heat and reflects.)
Emissions & warming are a problem, but they are problems that will be solved long before Ohio becomes oceanfront.