The Process of Oxygen Cycle
Our home, the world is the most incredible and the weirdest place in the whole universe… It is a living, breathing, working planet. It has weird connections, the near misses, and the lucky breaks that built our amazing world. It contains everything that’s important to us. It contains life. From the space, Earth is definitely the Blue Planet. We think we know our home, but once we see it from space it hits us.
Earth grants us so many gifts that come so naturally, we don’t even think about it. For instance, breathing. There is nothing more natural than breathing. We do it more than 23000 times a day. If we knew even half of what it takes to make the oxygen we need, it would take our breath away. And if we want to know about breathing, we should talk to an astronaut. The astronaut Chris Hadfield describes his worst-case problem in the space like this:
My first spacewalk, holding on to the outside of the spaceship, with nothing except the sound of my own breathing. And then while I was working, suddenly… I had a searing pain in my left eye. Like somebody had just stabbed me. My eye just snapped shut and it started tearing up. But the trouble is, without gravity tears don’t fall. The tear just gets bigger and bigger. It got big enough that it became a little lake of water that went across the bridge of my nose… Into my other eye. It was the worst-case problem. I had contamination in my suit. I had to flush it out. I reached up, turned this little valve, popped it and suddenly could hear, “Ssssss, sssss. As my precious supply of oxygen hissed out into the empty vacuum of space.
As far as we know, Earth is the only planet where we can breathe. Without oxygen, our lives would be very different indeed. In Dallol, Ethiopia there is an acid lake which is dangerous places to visit because the ground spits acid and the air is toxic. In that lake, there is no fresh water and so no plants grow there. Thus we don’t see any insects or birds there. But the scientists have found one thing that lives in that dangerous place. It is a different type of bacteria which lives in a lake of acid and doesn’t use oxygen. It is absolutely tiny because without oxygen it cannot produce energy to grow. Every time we breathe in, oxygen mixes with the food we’ve eaten and creates energy. The power that enables larger, more complex creatures to exist.
Our planet is literally bursting with life, so how on earth is there enough oxygen for everyone? The answer is very surprising. The cycle begins in a desert. A dessert made of salt. Sometimes the salt dust storms are huge. They can be pretty amazing when we see them from space. Every year about 27 million tons of that African dust we can see from orbit drops out of the sky into the Amazon Basin. And it’s the perfect fertilizer. And as plants grow, they turn carbon dioxide into oxygen.
One single tree can produce enough oxygen to support two people. And the Amazon Rainforest is seventeen times the size of the UK and Ireland together, producing 20 times more oxygen than all the people on the surface of the Earth could consume. But, that oxygen doesn’t leave the Amazon. There are so many animals living in the Amazon Basin and they use all that oxygen up.
Scientists have been working in the Amazon Basin and they have uncovered the surprising way the rainforest helps the whole planet breathe. Trees suck up water from the forest floor. When the water hits the top, the combination of sun and wind turns it into a flying river. If it was a normal river it would be the largest on the planet. Even bigger than the Amazon river beneath it.
This river of clouds is 5,500 miles long and up to 4 miles high. It flows across South America. The clouds condense into raindrops, which then race down the slopes and flow directly back into the Amazon Basin. They erode the rock and turn it into sediment until all those nutrients are dumped into the ocean and a whole other world.
And there is an extraordinary organism which is four times thinner than a human air is waiting for those sediments. It’s called a diatom. Diatoms are the secret to the Earth’s oxygen supply. They use silica from the ground up a rock to create new shells, which allows them to reproduce. Their population doubles every day. Then they begin to photosynthesize to produce oxygen. And one of those breaths that we consume each day is entirely provided by those little diatoms under the sea.
Sometimes we see a local area in the oceans has an entirely different color from space. At those times we are looking at is microscopic life. Diatom blooms that reflect the light differently, so that they show up from space. It may cover hundreds of miles. It is very interesting because we don’t notice the diatoms around us when we swim. But when we’re in space, we see the vibrant colors of life, the blues, and the greens. There are trillions of them in every ocean.
Diatoms keep us alive. They around the world have to get their nutrients in different ways. Glaciers are unusual. They can slide in sudden spurts. Just one collapse dumps thousands of tons of ice into the sea. And that powdered rock is the perfect diatom food. Glaciers move really fast and dumping tons and tons of nutrients into the sea. When the nutrients run out, the blooms fade and most of the diatoms die.
But diatoms are important not just because of what they do when they’re alive, but also what they do once they’re dead. When the diatoms die their carcasses slowly fall to the ocean floor where they carpet it in a layer half a mile thick. We call it ‘marine snow’, and that’s exactly what it looks like snowflakes. But unlike snowflakes, they never melt and over millions of years the sea beds rise. Then the ocean levels fall and the ocean floor becomes a salty desert. The desert that blows all the way to the Amazon. And the dust that makes the rainforest grow. It just goes to show how incredibly interlinked everything is. Everything is connected with the other things on the planet. All the systems literally are working together.
The Earth has a blue sky and the atmosphere gets very thin if we go further. And if we can actually walk to the city where the oxygen starts to run out. In La Rinconada, Peru the majority of the people suffer lung problems because there’s only half the amount of oxygen there. When Spanish settlers first arrived here, the lack of oxygen killed many of their babies at birth. And it is the limit for us. We can’t live any higher.
Without enough oxygen, our organs can start shutting down and it can happen very quickly. It’s vital that we get enough oxygen, but too much can be just as dangerous. We see it when we blow on a little tiny fire, oxygen turns that tiny spark into a flame. And it’s exactly the same for the whole planet. A rise in oxygen levels can threaten life on Earth.
Too much oxygen fries us and too little oxygen makes us choke. The balance of oxygen is crucial. Although we don’t fully understand how the Earth manages it, the amount of oxygen in the atmosphere has been surprisingly constant. 20.95 % of the atmosphere has always been oxygen since the beginning of the world. That’s really weird.