Somewhat off topic comment, but in 2003, Bill Bryson's book "History of Everything" states that anthropogenic CO2 output is 7billion metric tons per year where natural CO2 output is 200 billion metric tons a year (mostly volcanoes IIRC)[0]. It left me with the impression, that an additional 3% a year is small and we have time before this becomes a crisis. For the record, Scientific American calls Bill Bryson "A Champion of Science".

Then when climate change appeared to accelerate, I assumed that it must because we are removing our carbon sinks and that deforestation is likely the more dominant cause than our +3% additional emissions.

Earlier this week, I revisited the above figure and according to Scientific American: "the world’s volcanoes, both on land and undersea, generate about 200 million tons of carbon dioxide (CO2) annually, while our automotive and industrial activities cause some 24 billion tons of CO2 emissions every year worldwide." [1]

At 3% I can see how a climate change skeptic might feel this issue is alarmist. But if it is 12,000% I don't see how anyone could honestly be skeptical that global warming isn't being caused by humans.

It is mind boggling that two authoritative sources could differ by 3000X. Any clarifying comments are appreciated.

[0] https://books.google.com/books?id=_CWlKRYLbIwC&pg=PA268&lpg=... https://www.scientificamerican.com/article/earthtalks-volcan... [1] https://www.scientificamerican.com/article/earthtalks-volcan...