(July 14, 2015) Unless
humans slow the destruction of Earth's declining supply of plant life,
civilization like it is now may become completely unsustainable, according to a
paper published recently by University of Georgia researchers in the
Proceedings of the National Academy of Sciences.
"You can think of the Earth like a battery that has
been charged very slowly over billions of years," said the study's lead
author, John Schramski, an associate professor in UGA's College of Engineering.
"The sun's energy is stored in plants and fossil fuels, but humans are
draining energy much faster than it can be replenished."
Earth was once a barren landscape devoid of life, he
explained, and it was only after billions of years that simple organisms
evolved the ability to transform the sun's light into energy. This eventually
led to an explosion of plant and animal life that bathed the planet with lush
forests and extraordinarily diverse ecosystems.
The study's calculations are grounded in the fundamental
principles of thermodynamics, a branch of physics concerned with the
relationship between heat and mechanical energy. Chemical energy is stored in
plants, or biomass, which is used for food and fuel, but which is also
destroyed to make room for agriculture and expanding cities.