Is the effect of Carbon Dioxide on temperature logarithmic?

Warmers talk incessantly, and catastrophically, about the need to reduce greenhouse gases. If the greenhouse gases in the atmosphere rise, so does the temperature, and soon enough we will all die, they say. But what would happen if the reverse were to occur? What if we were too successful at reducing greenhouse gases? Can we actually calculate the correct amount by which to reduce, and what would happen to temperatures? Would a 1% reduction in CO2, for example, reduce temperatures by 1%.