Volcanic eruptions are often discussed in the context of climate change because they release CO2 and other gases into our atmosphere. However, the impact of human activities on the carbon cycle far exceeds that of all the world's volcanoes combined, by more than 100 times.
To put it in perspective, while volcanic eruptions do contribute to an increase in atmospheric CO2, human activities release an amount of CO2 equivalent to what a Mount St. Helens-sized eruption produces every 2.5 hours and a Mount Pinatubo-sized eruption twice daily.