Sometimes, a message must be delivered in a certain package in order to have impact.
Despite ubiquitous reminders to protect the environment, it can seem at times like the earth has a limitless supply of clean air and water, and an inexhaustible capability for cleaning itself. I think this image packages the "environmental message" in a way that may help debunk those notions of limitlessness and inexhaustibility.
Even more shocking is the amont of water that is spread thinly over the planet's surface and scattered through the atmosphere. That small amount of water is arguably more polluted and harder to clean than the air.