So, damn. I was hoping for a very cool report on how we would die instantly in a fiery explosion, but it's just dumping more carbon into the atmosphere and slowly worsening climate change.
Volcanoes release less than 1% of the CO2 of anthropogenic emissions, according to USGS. But they also have a cooling effect by releasing sulfur particles that reflect sunlight. So yeah, volcanoes pretty much a wash, or at least de minimis compared to humans.
I don't think you're accounting for the massive difference in scale when considering a super-volcanic eruption. It would cause global famine and a massive die-off of most species including humans. If Yellowstone went off, for instance, we would be living under volcanic winter for at least a decade. It would release something like 1,000 gigatons of CO2, which would be roughly equivalent to all human caused CO2 since the industrial revolution, and it would do it all at once.
By way of example, the Toba supervolcano was so devastating and caused so much death it literally created a pronounced genetic bottleneck in the history of human genome.
Well, no. The article is not talking about the kind of catastrophic supervolcano eruption that you are. It's talking about small-scale emissions, 4000-5000 tons per day from a single supervolcano crater in Italy, which totals less than 2 million tons per year or about 0.005% of global CO2 inventory.
You introduced the concept of a catastrophic supervolcano eruption for the first time. That wasn't the topic of the article or the comment chain I responded to.
It's talking about how those small-scale emissions indicate higher risk of super-volcanic eruption, which is the part of the topic of the third section of the article and is the implicit concern throughout the article.
There are two distinct categories of impacts: carbon dioxide emissions from volcanoes (occurring presently) and supervolcano eruptions (rare even on geologic timescales but possible).
The comment chain I was responding to started with a quip about conservatives claiming that CO2 emissions are volcanic in nature. The follow-up discussion was about the relative magnitude of volcanic CO2 emissions occurring presently, including USGS figures on the magnitude of those emissions relative to anthropogenic sources. All of this discussion pertained to what is happening now.
You are making a separate point that a catastrophic supervolcano eruption would have much broader impacts. No one is disputing that. You could have a long-lasting volcanic winter, decrease in insolation and surface temperatures, widespread crop failures, etc. That's all true. It's also not relevant to the discussion of present impacts that was underway. Again, if a supervolcano eruption actually occurs in our lifetimes, global warming will be the least of our problems.
I understand what you're saying. I'm just saying it's relevant because the article and underlying research article are ultimately about increased volcanic activity at the site of a supervolcano. The purpose of their research was to establish what was underlying volcanic activity that might indicate an eruption from other cause of emissions.
Also, noting how destructive supervolcanoes would hypothetically be is relevant just because it's crazy.