As I recall, the human contribution to total emitted carbon dioxide gasses is around 5%. The usual argument is that the CO2 both leaving and being put in the atmosphere was in balance before, and now it is not. Since about 1880 we have seen the atmospheric CO2 level go from about 280 PPM to around 400 PPM. It was 230 PPM in the preindustrial period. It is expected to reach 800 PPM by the year 2100. As long as it doesn't go higher than that, I think that this is more beneficial than detrimental.
Previously, I did my math wrong. I thought that an atmospheric increase of CO2 from 280 PPM to 400 PPm was a 70% increase, but that was because I did a brain fart on the math. Instead, it is about a 43% increase. I just now discovered my mistake. Doing a new calculation, based upon the 0.85 temperature increase since 1880, I get a new climate sensitivity to a doubling of CO2 of 1.98 degrees Celsius. However, the IPCC changed the low end of their range to only 1.5 degrees because they accepted papers that said that this was the climate sensitivity based upon 20nth century data. So other people are looking at recent data and are coming up with Climate Sensitivity numbers. The generally accepted range by the IPCC is from 1.5 to 4.5 degrees. Whereas the skeptics think that 1.5 degrees is the most the climate sensitivity could be, the IPCC think that it will be at least this much, if not much higher. I just watched a climate scientist claim that it is 6 degrees celsius.
I just found yet another source claiming that it will take 5,000 years for the polar ice caps to melt. This is the disaster scenario that the alarmists warn about. The temperature has to warm about 5 degrees celsius for this to happen. Obviously we have plenty of time to change course if the Climate Sensitivity is more than I think it is.
Correlation is not the same as causality. The biggest driver of temperature is solar variation. Ice core samples going back hundreds of thousands of years show that temperature increases precedes CO2 increases, and not the other way around. This is because warmer air causes the oceans to release more CO2. Although the two things are correlated, it doesn't necessarily mean that there is a clear causality relationship between CO2 and temperature. When I looked at temperature data, sometimes the two went in opposite directions. Although I am certain there is a greenhouse effect, CO2 may not the main driver of temperature.