Breathing

Feel your next breath come in, filling your lungs with air.  In the few seconds before you finish exhaling that breath, your body has exchanged millions of oxygen molecules for carbon dioxide that flows out into the atmosphere.

The motion of the molecules and the currents of the wind mix your exhale with that of all the other people and animals on the planet into the swirling layer of gas that covers the Earth.

Light from the Sun streams out into space.  A tiny bit of it reaches the surface of Earth, and a tiny bit of that is captured by chlorophyll molecules in plants and used to build sugars from carbon dioxide captured from the air, releasing oxygen back into the atmosphere.

A blade of grass in someone's yard; an ancient tree in a tropical rainforest; a phytoplankton cell floating in the ocean - any of these - perhaps all of these - have produced the oxygen in the breath that is entering your lungs right now.  Your exhale disperses molecules of carbon dioxide that drift and ride the currents of the wind to the ends of the Earth until they are captured once more by a plant, completing the cycle.

The Earth spins, ever turning toward and turning away from the energy streaming in from the Sun.  At any time, half the world is producing more oxygen than it is using, and the other half consuming more than it produces.

There is no way to isolate yourself from this process.  We take for granted that the air we breathe will sustain us,  but when we understand that the oxygen we need with each breath has been produced by another life form somewhere on the planet, and that our exhale will someday become part of a tree or a rice plant, a rose or a strand of moss on the forest floor, we realize our life is intimately connected with all life on Earth, through the process of breathing.