How to plants clean the air?

We often hear that forests are the lungs of our planet because they provide clean air, but how do plants  clean the air we breathe?

First, let's travel back in time about 4.6 billion years into the past, to an age where our planet was not at all like where we live today. On this primitive Earth, there was a lot of volcanic activity, and the fumes that they released gave shape to Earth’s atmosphere. However, this very young atmosphere contained 10 to 200 times more carbon dioxide (CO2) than today’s atmosphere.

Around 2.7 billion years ago, the first living organisms (single-celled bacteria called cyanobacteria) developed a way to survive on Earth with high levels of CO2. These bacteria used the energy of sunlight to drive photosynthesis (photosynthesis is from the latin words photo = light and synthesis = combine). With photosynthesis they transformed CO2 and water molecules into sugar , for food, and oxygen molecules, which were released into the air. The higher concentrations of CO2  meant more food for these bacteria, which increased the oxygen concentration in our atmosphere. The higher levels of oxygen helped other organisms to evolve, making more complex living forms, from animals to plants. Plants inherited the photosynthesis properties of cyanobacteria. 

On today's Earth, CO2 makes up about 0.04 percent of our atmosphere. Most of the CO2 comes from industrial processes, like burning fossil fuels, which pollute the air. So, plants help us get rid of CO2in our atmosphere via photosynthesis, using it as a food source and giving us oxygen in the process. However, the uncontrolled increase of industrial processes and deforestation are rapidly increasing the concentrations of CO2and other greenhouse gasses in our atmosphere. While the concentration of CO2 is still quite small, slight increases have had drastic effects on our Earth’s climate and ecosystems. Help the Earth and plant a tree!

By Dr. Jose Veleta