The problem I have with all of this is the people who make the most noise about it are so certain about the exact cause and then, they show 100 years of temperature data. That's not remotely close to what's needed to form an accurate conclusion but it does amplify their statements.
Not long ago, I saw an article stating that volcanic activity produces far more CO2 than scientists had assumed. I wasn't aware that scientists assumed anything, I thought they would have theorized and then tested these ideas, in order to prove them correct, or incorrect. Kilauea has been erupting continuously since January 3, 1983- how much CO2 has that added to the atmosphere? What about the other large eruptions like Mt Pinatubo and Mt St Helen?
It's denial to state that human activity isn't a large part of the cause, but it's arrogant to think that we can reverse it quickly. The climate is too complex and all-encompassing to make it change in a short time.
Here's a link to some info about volcanic activity-
https://www.researchgate.net/publication/275946715_Global_temperature_response_to_the_major_volcanic_eruptions_in_multiple_reanalysis_datasets