Do you know where the oxygen we breathe actually comes from?

Fun fact: We breathe 550 litres of oxygen everyday. Yes, every single day. This intake of oxygen can be credited to the fact that the average human being takes 20,000 breaths every single day to stay alive. Sounds mind-boggling, right? Needless to say, oxygen is an indispensable element for survival. However, did you know where the oxygen that we breathe so freely every single day actually comes from? 

Where oxygen actually comes from 

Elementary school science has taught us that oxygen comes from trees. The drill is familiar by now: leaves soak in carbon dioxide from the atmosphere during photosynthesis and release oxygen as a by-product. However, trees aren’t the only major sources of oxygen. Experts have concluded that more than half of the oxygen in the atmosphere comes from oceans. It is estimated that between 50-80% of the oxygen we breathe comes from the ocean. Yes, 50-80%!  Yes, you read that right. 

A closer look at the record books offers up definitive proof. Fossil records have noted that plants started appearing on the earth 470 million years ago, long before dinosaurs roamed the earth. However, oceans have been producing oxygen for billions of years before that. It is also noted that land plants have evolved from marine algae, making oceans the original source of the production of all oxygen on the earth. 

How oceans produce oxygen

So, how do oceans shoulder the responsibility of the majority of oxygen production on earth? All credit is owed to marine photosynthesizers. The list of major contributors are headlined by phytoplanktons, they are microscopic organisms that live in watery environments. The process of photosynthesis is similar to trees: upon absorption of sunlight, phytoplanktons produce energy and expel oxygen into the atmosphere as a result. It is said that one single drop of water can possess upto thousands of these microscopic beings. Now, pause for a moment and imagine how much oxygen can be produced by an ocean full of them. This truly makes oceans the ‘lungs of the earth’. 

Why we need to save planktons

However, as the climate crisis progresses further, phytoplanktons, among other marine photosynthesizers, are finding their lives in danger. As the ocean waters start warming up due to climate change, it has been noted that the planktons have decreased by a significant amount in the past decade. Other culprits include run-off from fertilisers and sewage that reaches ocean waters, animal waste as well as the production of nitrogen from the burning of fossil fuels. If we hope to breathe freely, and allow our future generations to do the same, it helps to take immediate steps in the day-to-day to reduce our plastic consumption, use less energy and contribute actively towards anti-pollution efforts. While planktons have been giving life to humans for billions of years, it is now our turn to ensure their survival.