An Atmosphere Black with Carbon
Since the outbreak of the Industrial Revolution, we have emitted nearly two and a half trillion tonnes of carbon dioxide into the atmosphere. Now we rack our brains how to push them underground.
I was so excited that night, I couldn’t sleep, recalls Michał Horodyski, a public transit worker from Reykjavik. “Finally, I got up, got in my car and drove to the volcano. In the darkness, I climbed the peaks leading to it, illuminating my way with a headlamp. There were no paths yet, the authorities had not had time to set up parking lots. But people already wanted to see the eruption. In the cold night, its blazing red looked phenomenal. The glow was visible from Reykjavik.”
The Fagradalsfjall volcano (which means “mountain in a beautiful valley” in Icelandic) is located fifty kilometres southwest of the capital of Iceland. It woke up on the evening of March 19, 2021, after more than six thousand years of sleep. Michał rushed to see it two days later.
When at the beginning of September we cover almost the same route together, the harsh alpine-tundra landscape is already a little civilized. Icelandic Mount Doom has taken a break and isn’t throwing lava flows from its bowels (to my chagrin, it will let loose shortly after my departure, only to fall asleep again a month later). The weather is so wonderful that I wonder where the famous Icelandic Low went. The sun is blazing and even the ocean chill doesn’t bother us. I am happy to breathe the crisp air that smells of salt, fish, and algae decaying on pebbly beaches. We’re walking, and that’s really all that matters. Left, right, mind the rocks. Slightly uphill, actually without much effort. I’d love to hike here more.
A basalt avalanche has overrun the neighbouring valleys in long flows, stopping at the earthwork dam which the Icelanders had built to prevent it from cutting across road 427 running along the ocean coast. Greyish blacks are marked by yellow-green boogers of sulphur. Here and there, grey smoke rises above the frozen lava. “It smells like a leaky coal furnace,” sums up Michał, who comes from Kraków, so he knows what he’s talking about.
The eruption of Fagradalsfjall has become a great tourist attraction. The car parks are already designated, the paths have been set, the webcam is up. Set on the nameless peak we climbed, the mobile phone mast is surrounded by a few dozen people. But there is so much space that no one gets in anybody’s way. Every now and then, my ears pick up the rustle of Polish. From above, we can see the frozen flows of lava – a lake in all shades of black. There must still be lots of heat underneath. The basalt is hot, maybe not glowing, but hot enough to denature the proteins that make up my body. Icelandic mountain rescue service have declared that they will not save anyone who enters the avalanche site and gets stuck. It’s too dangerous.
Light planes, helicopters, and drones make passes over the recently formed crater. Michał, although he himself had flown over the volcano in an airplane, sums up this aerial gathering with a profanity. We tolerate people around us, but we do not like the machines, which detract from the pristine, post-apocalyptic landscape, overly civilizing its austerity. They buzz, they annoy, they pollute the air with engine secretions. They disturb the black silence. They infantilize.
On the way to the volcano, we drove through the fishing town of Grindavik, inhabited by just over three thousand people. Nearby is Bláa Lónið, or the Blue Lagoon, a popular outdoor spa created with waste water from a nearby geothermal power plant. It attracts not only tourists, but also locals. In the milky-blue water, its colour due to the high content of silica, temperature reaching nearly 40 degrees Celsius, social life happens, up to and including, I am told, close encounters of the third kind. The town of Grindavik itself won a plebiscite for the happiest town in Iceland three years ago, but in March 2021, just before the Fagradalsfjall eruption, the earth there was shaking two thousand times a day. The inhabitants were fed up.
“This is the happiest town at the moment for two reasons,” laughs Michał, as we eat a nice lobster soup in the coastal Bryggjan Kaffihus (you pour it yourself from a large cauldron, trying to drain off the thin stuff and keep as much thick as possible in the ladle). “Because it won the plebiscite and the earth isn’t shaking anymore!” In addition to the port and a sports centre with a geothermal swimming pool, Grindavik is composed primarily of single-family houses. No wonder it’s nice living here.
On our way to the capital of Iceland, we go down a gravel road covered with black volcanic slag. There’s a lot of roads like this here. The pebbles rattle, hitting the metal of the chassis and the interior of the mudguards. We are headed for the lava cave of Leiðarendi.
Travelling down a rift valley, I am struck by its resemblance to the Great Rift Valley of Africa. The wildlife out here, though, is completely different. Instead of savannah, bush, herds of gnu, antelope, gazelle, elephants, zebras, giraffes, lions, cheetahs, and hyenas, we see a lunar landscape covered with sheets of frozen lava, garnished only by sparse tundra vegetation. But the impression is irresistible because the landform is exactly the same. The steep slopes on both sides of the valley tell us that the magma erupting from inside the Earth has spread apart tectonic plates that form continents on the surface of our planet. One day, more eruptions will occur, the valley will widen and its slopes will move even further apart. Perhaps someone else will then wander here and also admire the roughness of this landscape, as well as the perseverance of the mechanisms that shape it. Over the next hundred million years, the landscape will be ground up in successive movements of tectonic plates that will join the Americas and Eurasia into a supercontinent.
Perhaps scientists will call it Amasia. If there’s anyone around to name it.
Leiðarendi is only two thousand years old. Such caves are created when the lower layer of magma flows out of the tunnel it has created and the upper one freezes, forming a vault. Shining our headlamps, we struggle over fragments of lava crust, which through water erosion broke off and fell to the bottom of the cave. Leiðarendi is 900 meters long, but it still feels like we are descending into the centre of the world. We can hear someone behind us. “Gentlemen, are you going to the exit?” he asks in Polish as he catches up with us. I lose my bearings for a moment. Are we going deeper into the cave, or are we heading out? My inner ear points me one way, then the other. I shake the feeling off. The man has probably closed a loop in the connected corridors of Leiðarendi. We point him to the surface.
Carbon In and Around Us
The Reykjanes Peninsula is Iceland’s geologically youngest region. Here, the mighty Mid-Atlantic Ridge emerges from beneath the surface of the ocean. The lava surfacing between the North American and Eurasian tectonic plates, which are spreading apart at the bottom of the Atlantic, forms the foundations of Iceland. The ground cracks along the entire island, a rift cutting across it from the southwest to the northeast. Across this crack, you can go from Europe to America and back in a few moments. You can even stand between the two continents.
All of Iceland is volcanically active, but the rift is the hottest. The local volcanoes are one of the natural gates through which carbon, the fourth most common element in the Universe (after hydrogen, helium, and oxygen), enters the atmosphere in the form of carbon dioxide (CO2). The carbon we have on Earth was forged in the thermonuclear fusion of aging stars. Exploding as supernovas, they scattered it across the cosmos. On Earth, carbon circulates in the environment in a never-ending cycle. Organisms also take part in this cycle, because – as biologists are known to quip – life is nothing more than an arrangement of carbon atoms. They form the skeleton, to which other elements can easily attach, building amino acids, and from them – proteins. Hence, organic chemistry is the science of carbon compounds.
They make up our diet, and one of the processes by which we get rid of carbon atoms from our bodies is breathing. Every year, we expel tens of kilograms of this element into the air by respiration; an order of magnitude less, we excrete in the form of faces, urine, sweat, and flatulence. Matter merely flows through us, kept in the confines of the human form by the matrix of our DNA. When, after repeated and less-than-perfect copying of this genetic information carrier, my cells are so degraded that the energy of the bonds between their atoms is no longer able to keep my organism working, I will die. My body – or actually not mine, because I will be gone – will then perhaps be cremated, and the carbon atoms forming it, after combining with oxygen atoms in a violent combustion reaction, will fly away into the atmosphere in the form of CO2. Like a soul to heaven.
The human body consists of almost 18 percent carbon (the rest of the elements that build us are primarily oxygen and hydrogen, constituting the water that makes up nearly 65 percent of a human). So, in my body there are currently 13 kilograms of carbon – unless I gained some weight over the winter. The atomic mass of carbon is rounded to 12 u, and that of oxygen – to 16 u (from “atomic mass unit”). The molecular mass of carbon dioxide is therefore 44 u (12 + 2 x 16), which means that the CO2 molecule is almost four times heavier than a carbon atom.
So if I were to expire now, and no-longer-my body were burned, almost 48 kilograms of carbon dioxide would be released into the air. In turn, if until-recently-my family decided to bury it, 13 kilograms of carbon together with the rest of formerly-my matter would be absorbed by invertebrates and microorganisms and thus reintroduced into the carousel of life. Carbon, whose atoms once formed the elemental skeleton of my body, would then pass to other, including larger, organisms.
This is nature’s so-called fast carbon cycle, measured in lifetimes. According to Earth Observatory, an official outlet of NASA (the US National Aeronautics and Space Administration), scientists estimate that between a billion and a hundred billion tonnes of this element flow through the Earth’s biosphere every year. Ashes to ashes, dust to dust.
It can happen that carbon atoms break out of the organic circuit and enter the water or atmosphere for a longer time, e.g. in the form of CO2. Such a molecule can stay in the atmosphere for a little over a hundred years. By then, it is most likely either absorbed back by photosynthesizing algae and plants (and from them it goes into the organisms of animals, including humans), or, via air bubbles, absorbed by sea waves or washed out of the air by rain. In combination with rainwater, CO2 creates a weak solution of carbonic acid that dissolves rocks and, together with washed out ions of some elements, including calcium, flows into soil, rivers, lakes, and the ocean. In the ocean, calcium ions react with bicarbonate ions to form calcium carbonate, which planktonic organisms and corals use to build their shells or internal skeletons. When these in turn die, they sink to the bottom of the ocean, where they are covered with successive layers of dead organisms. Their remains are compressed into limestone for millions of years, which in the mill of collision and subduction of tectonic plates (i.e. pulling or pushing one plate under or over another) can reach the upper layers of the Earth’s mantle, where it melts under the influence of temperature and pressure, creating minerals called silicates and releasing carbon dioxide. The CO2 molecules are then carried by the magma to the cracks of the Earth’s crust – among others, the ones in Iceland – and fly back into the air through volcanoes.
This is what’s called the slow carbon cycle. The journey of a carbon atom between the atmosphere, rocks, soil, the hydrosphere, and the atmosphere again takes as much as one hundred to two hundred million years. Scientists estimate that all the volcanoes in the world emit between 130 million and 380 million tonnes of carbon dioxide per year.
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