The volcano in Iceland is a reminder of how ultimately precarious our situation is here on Earth. There’s just no telling what the planet’s systems have in store for us. We build entire civilizations on the assumption of permanence. But in moments the ground — or skies — can start shifting.
As EyjafjallajÃ¶kull continued spurting dark clouds across Europe causing human chaos, scientists simply could not say for sure when the end of it was near.
No known end. And of course the scariest part is that this kind of thing isn’t all that unusual in Earth’s past. Although EyjafjallajÃ¶kull is happening in an inopportune spot, it’s not particularly large either. Now’s the time to bone up on past volcanic occurrences.
We’ve all heard of the 1991 eruption of Mount Pinatubo in the Philippines — the largest eruption in living memory — which caused average global temperatures to drop by almost a degree Fahrenheit as a haze of sulfuric acid droplets prevented sunlight from reaching the Earth. Some 800 people died from houses that collapsed under accumulated wet hot ash, and of course there was untold damage to nearby communities, forests, and agriculture. How fast things change: these days, the volcano is a tourist destination.
Well, step aside Mount Pinatubo. There are no images for this next one. The Mount Toba “super-eruption” about 75,000 years ago in Sumatra has been called the “eruption that brought humanity to its knees.” It brought on a six year “volcanic winter” and then a thousand year snowball Earth.Â Scientists think a bottleneck in the human genetic code stemming from around that time could have been a massive die-off of humans, then hunter gatherers, to a population of only 5,000 individuals (see, we are all related). These days Toba’s crater has become a peaceful lake where buffaloes graze and the ethnic Batak people work their rice patties.
So what’s all this have to do with global warming? Well, volcanic eruptions temporarily (or not so temporarily) lead to global cooling, though, of course, also cause quite a bit of destruction so we don’t exactly want them to pop off. But in the long term, they are actually adding quite a bit of CO2 to the atmosphere. Think of them as balancing out the Great Carbon Cycle.
But as Virginia Polytechnic Institute geologist Dewey McLean points out:
Today, our burning of the fossil fuels coal, oil, and gas is like a human volcano that is releasing vast amounts of carbon dioxide into the atmosphere.
We’re a human volcano. He’s kinda right.
Despite all the carbon it spewed into the air, EyjafjallajÃ¶kull has, in an odd way, actually helped alleviate climate change.