How do trees give earth all its oxygen?

Introduction to Oxygen Production

It is a common misconception that trees are the primary source of the Earth’s oxygen. In reality, while trees do contribute significantly to oxygen production through the process of photosynthesis, they are not the sole contributors. The majority of Earth’s atmospheric oxygen, approximately $70\%$, is actually produced by marine plants and other plant-like organisms that thrive in our oceans.

The Role of Photosynthesis

Photosynthesis is the fundamental process through which both terrestrial and marine plants convert light energy into chemical energy. In this process, plants capture sunlight and utilize its energy to split carbon dioxide ($\text{CO}_2$) and water ($\text{H}_2\text{O}$). This reaction produces glucose ($\text{C}_6\text{H}_{12}\text{O}_6$) for the plant’s energy needs and releases molecular oxygen ($\text{O}_2$) as a by-product:

Marine Plants as Major Oxygen Producers

The dominant contributors to oxygen production are not trees but microscopic organisms known as phytoplankton, which inhabit the ocean. Phytoplankton includes various types of photosynthesizing organisms such as:

• Cyanobacteria
• Green algae
• Diatoms
• Dinoflagellates

Despite their small size, which makes them invisible to the naked eye, these organisms perform a crucial role in the global oxygen cycle. When they aggregate, they can form visible blooms that may appear as green patches in the ocean.

Why Oceans Are Key to Oxygen Production

The vastness of the oceans plays a significant role in the overall contribution to Earth’s oxygen supply. Given that over $70\%$ of the Earth’s surface is covered by water, it is logical that marine life would be responsible for a substantial portion of atmospheric oxygen.

Conclusion

In conclusion, while trees indeed produce oxygen through photosynthesis and are vital to our ecosystem, they are not the primary source of the oxygen we breathe. Instead, it is the myriad of marine plants and phytoplankton that predominantly sustain the oxygen levels in our atmosphere. Understanding this distribution of oxygen production helps us appreciate the intricate balance of life on Earth and the importance of both terrestrial and aquatic ecosystems.