I never claimed CO2 was 'bad'. CO2 is what it is. CO2 absorbs radiation at certain frequencies, that is a scientific certainty. No CO2, that is, no absorption of the energy at frequencies it absorbs, means the earth would be a lot cooler than it is now, that is, uninhabitable for us. As levels of CO2 in the atmosphere increase, so does the absorption of the radiation from the sun at the frequencies specified. That is, the earth will be warmer. The level of CO2 in the atmosphere is, IIRC, projected to double. That will not cause a doubling of the earths temperature, (CO2 only absorbs a certain range of radiation, also the relationship is not linear, that is, if you keep increasing the amount of CO2, you will not keep increasing the ability to warm the earth. CO2 is effective at the very low levels (IIRC 300PPM) in the atmosphere at already capturing most of the radiation that is coming in. However, increase it, and the amount of radiation captured will still increase, to the so that the earth will still get warmer.