We have a notion that Amazon rainforests are the lungs of our planet. But do they provide enough oxygen? How do these forests provide oxygen? How consistently do these forests release oxygen into the atmosphere?
The role of Amazon
The Amazon rainforests produce 20% of the planet’s oxygen, 20 times more than what humans require. And there are about 10 million species in these forests. Dense forests also imply a torrential amount of rain. One tree here can support the breathing of 2 people (if you want to know how much CO2 is absorbed by a tree, here’s a read). Now, things get interesting.
Scott Denning from The Conservation said “The oxygen produced by photosynthesis is absorbed by the species living in the forests. None of the oxygen supply gets outside these forests.”
Then how come we get enough oxygen supply for the sustenance of mankind?
Enter Diatoms
Diatoms are single-celled algae with shells made of silica, that look similar to glass, usually found in the oceans, waterways and soils. These are the only organisms on the planet made of transparent cell walls.
Now, what do these do? These diatoms convert CO2 in the atmosphere into Sugar/ carbon with the help of the sun’s energy using photosynthesis. This process releases oxygen into the atmosphere. These diatoms generate 20 to 50% of the Earth’s oxygen, taking about 6.7 billion tons of silica from the waters they live in.
This photo by NASA is of a massive sandstorm blowing off the northwest African desert that has blanketed hundreds of thousands of square miles of the eastern Atlantic Ocean with a dense cloud of Saharan sand. The massive nature of this particular storm was first seen in this SeaWiFS image acquired on February 26, 2000, when it reached over 1000 miles into the Atlantic.
These storms along with the rising warm air can lift dust 15,000 feet or so above the African deserts and then travel across the Atlantic, many times reaching as far as the Caribbean where they often require the local weather services to issue air pollution alerts as was recently the case in San Juan, Puerto Rico.
NASA revealed that these storms export 182 million tons of dust every year, with 27.7 million tons settling in the Amazon River basin.
Even though the Amazon has plenty of nutrients, rains wash away a lot of the phosphorous in the soil, a fertilizing nutrient critical to plant growth. This dust in the form of the storm brings in a lot more new phosphorus, enabling the growth of plants. These plants absorb water and are then released into the air. This air containing water hits the Andes with rainfall and then all the sediments containing nutrients join the ocean.
C’mon, what has this storm got to do with oxygen?
Remember Diatoms? These nutrients joining the ocean are food for Diatoms. And then the Diatoms produce enough oxygen on the planet.
So, if you are burning the Amazons, you aren’t directly taking away the oxygen. You are taking away the rain which brings food to these diatoms.
And living diatoms just aren’t found in the Atlantic near the Amazon. They live everywhere they can get food. They even live in the cold waters of the Arctic. The melting glaciers grind the soil and bring it into the waters. This is yummy for the Diatoms!
But what if there are too many glaciers melting? Sea-level rise seems obvious but there is another effect. Too much food is given to the diatoms which in turn release too much oxygen into the planet’s atmosphere.
And this is a bane. When there is too much oxygen, wildfires become a common phenomenon.
Well. This is some stuff to digest, isn’t it?
That’s how our planet operates, the complexity being the norm. One disturbance in the ecosystem has many repercussions.
