Scientists have been monitoring various gas emissions at Hawaii's Kilauea volcano measure daily CO2 release at between 8000 and 30,000 metric tones of CO2/day, or  300 thousand to 1 million tons/yr. That compares to human caused and natural CO2 emissions of about 30 billion tons/yr.    https://hvo.wr.usgs.gov/volcanowatch/archive/2007/07_02_15.html
So that Hawaiian volcano emits at most about I/30,000 or 0.00003% of global CO2 emissions.