There was a famous case of one volcano in Iceland that stranded a bunch of airplanes resulting in net greenhouse savings. That is the amount of greenhouse gas that the volcano emitted was less then what the airplanes would have otherwise emitted if the volcano wouldn’t have stranded them.

That was a fairly small eruption though and didn’t emit a lot of greenhouse gas. There was another eruption last year in the same place as this one, and it was even smaller. This one seems to be larger then last years eruption, but I would be surprised if this one actually emitted more greenhouse gas over the next year then e.g. Iceland’s aluminum industry.

So to answer your question if we can afford it. The answer is yes. We are experiencing about average number of volcanoes globally, and the greenhouse gas emissions of volcanoes has remained steady for the last few millions years, and we are not seeing any increase. In comparison human greenhouse gas emissions are rising dramatically, we should probably focus our efforts there.

EDIT: Here is a short article (in Icelandic) about the greenhouse gas emissions of last year’s eruption: https://kjarninn.is/skodun/eldgos-og-co2/

You are correct. The Icelandic volcano will release CO2. Volcanoes play a vital role in the carbon balance in the Earth's atmosphere. If it were not for volcanoes releasing CO2, Earth would be a lifeless snowball planet with little or no greenhouse gases containing the heat. Moreover, that CO2 will be reabsorbed into the crust of the earth through the process of weathering, CO2 + H2O → H2CO3, CaCO3 + H2CO3 → Ca2+ + 2HCO3-. This will also happen for all the CO2 that human activity is belching into the atmosphere. The problem is this will take geologic time for the problem to correct itself.

If I recall the math, the yearly total eruption of actual magma mass is on the same order as the yearly mass of CO2 emitted by humans (some like 80billion tons of magma vs 30billion tons of CO2). The percent, by mass, of dissolved CO2 in that magma is in the single digits.

So to answer to your question: It's a drop in the bucket.

A year's worth of volcanism emits some amount of CO2, and an ~equivalent amount is consumed and stockpiled by other natural processes. It's why in the long-term of hundreds of thousands of years, CO2 concentrations in the atmosphere are more or less stable.

Unfortunately, when humans started emitting millions of years of CO2 stockpiles, the natural processes of the carbon cycle that take CO2 out of the atmosphere haven't magically scaled up to compensate.

Volcanism slowly drips water into a bucket that has a small hole in the bottom. Over the course of hundreds of thousands of years, the water level in the bucket stays more or less the same. Humans come along, and start filling the bucket with a firehose, and then start questioning if they, or the volcano are the reason the bucket overflowed.

This is basic stuff that's covered in any high-school-level textbook on the subject.

“There is no question that very large volcanic eruptions can inject significant amounts of carbon dioxide into the atmosphere. The 1980 eruption of Mount St. Helens vented approximately 10 million tons of CO2 into the atmosphere in only 9 hours”

It will release approximately no CO2.

True! We should build a huge biodome above Iceland to contain the CO2.