It's a point I've made here more than once; if you're trying to convince someone of something, your argument is not made stronger by lying about it.
The reason this comes up today is the horrible situation in Iceland, where (at the time of this writing) the people of the little village of Grindavík on the south coast of the Reykjanes Peninsula, due south of the capital city of Reykjavík, have been evacuated and are waiting for a volcanic eruption that stands a good chance of destroying the town completely. The buildings and roads in the town have already sustained heavy damage from nearly continuous earthquakes, and the latest estimate is that there are places where the magma is only five hundred meters below the surface. An eruption is nearly certain -- how extensive it will be is unknown. (The village is only a few kilometers away from Fagradallsfjall, the volcano I got to see erupting when I visited Iceland in 2022.)
This is certainly awful. But the whole situation is made worse because every time there's a volcanic eruption, it brings the climate change deniers howling from the dark corners where they hide, claiming that (as one of them put it) "the Climate Scammers conveniently ignore that a single volcanic eruption puts hundreds of times more carbon dioxide into the atmosphere than cars do. Climate ups and downs happen all the time, and natural processes account for nearly all of it. Wake up!"
Which would be a good argument if anything about it was true.
The "hundreds of times more" statistic is about the right factor -- but the inequality points the other direction. Here's the actual situation, as per the National Oceanic and Atmospheric Administration:Mark Gongloff points out, writing for Bloomberg, the 1980 eruption of Mount Saint Helens spewed ten million tons of carbon dioxide into the atmosphere, which seems like a lot until you find out that our burning of fossil fuels does that every two and a half hours. Geologists estimate that even a cataclysmic eruption like the Yellowstone Supervolcano emitted on the order of thirty gigatons of carbon dioxide -- about what our fossil fuel use accomplishes every single year.
But we can't keep going as we are. If this past year's insane weather didn't convince you of that fact, you're being willfully blind.
And the whole thing is not helped by circulating wildly wrong information whose sole intent is to lull everyone into further inaction. I have no doubt that at least some of the people who are posting this stuff don't know it's wrong, and are guilty of the rather common sin of neglecting to fact-check. But the ones who write these posts and create these memes -- they know it's a lie, and they do it anyway.
Which is somewhere beyond reprehensible.
So please, please, please... if you see someone posting this claim, tell them they're wrong. Link this blog post if you like, or (better still) send them to the NOAA and USGS sites that lay the data out in unarguable form. Because this is a falsehood with serious repercussions -- like endangering the long-term habitability of our own home world.