I am guessing that you do not understand that the scientific consensus is only that it has warmed in the last century,
and that Human activity is likely involved.
The consensus does not include any specific contribution by CO2, or any negative consequences.
Scientific Consensus: Earth's Climate Is Warming
"Multiple studies published in peer-reviewed scientific journals
1 show that 97 percent or more of actively publishing climate scientists agree
*:
Climate-warming trends over the past century are extremely likely due to human activities."
There is scientific evidence that increasing the CO2 level will cause some warming.
The actual amount of warming caused from a particular increase in CO2, has not, and likely cannot be
validated in a repeatable scientific experiment.
The vast majority of predicted negative results from increases in CO2, are a result of Computer models,
which also have not, and likely cannot be tested by repeatable scientific experiment.
If you have any actual empirical evidence about how the climate will respond to increases in CO2,
then please cite and quote the sections of the peer reviewed papers, that support that claim?