Energy, Organisms, and the Environment
Why does something so intangible matter so much?
What is energy?
Energy is all there is, and yet it’s indefinable. We could not live without it; it affects every aspect of our lives, yet it’s elusive and ephemeral.
It’s the power to do work and the ability to get things done, but what does that actually mean? It can’t be seen; it doesn’t come in packets or particles, yet it is the key component of life on earth.
In Alaska, in August, grizzly bears gather in the waterfalls of Katmai National Park to catch salmon. They do this to prepare for hibernation laying down fat reserves before winter. The salmon are fulfilling their migration back to their spawning grounds. In both cases, energy is being gained, or energy is being expended.
As bears and salmon convert valuable chemical energy reserves into kinetic energy (movement), energy transformations occur. And as the bears consume the salmon, they assimilate their chemical energy into energy reserves. In each case, a balance has been struck between the energy gained and the energy lost. A ledger of energy in and energy out.
For the salmon, the journey is one way, and the energy they require will allow them to fulfill their reproductive cycle and ensure the species' survival. For the bears, the cost-to-benefit analysis is calculated through evolution and expressed as an instinct that persuades them that the energy gained from standing in the fast-flowing waters catching fish will vastly outweigh the expenditure and see them through the energy desert of the winter months.
Energy conversions, light to chemical, chemical to kinetic, are at the heart of all interactions played out. Each energy conversion represents a step on a food chain, and each is a dwindling and dissipation of the energy available.
All organisms exist on a knife edge. Constantly needing to absorb energy, transform it and utilize it for life processes against the will of the universe. By some definitions, this is all life is. Bounded microenvironments capable of transforming energy to maintain low entropy states.
In a closed system, entropy and disorder will increase, and energy will dissipate. These are the rules that all organisms live by. However, life does not (despite often being accused of it) violate this 2nd Law of thermodynamics for one important reason.
The earth is not a closed system.
Every day it receives 173,000 trillion joules per second (173000 terawatts) from the sun and has done this continuously since its formation 4.5 billion years ago.
The challenge for living things is to channel that energy to do life's work: Movement, respiration, growth, reproduction, and excretion.
They do this in two ways, directly or indirectly. Autotrophs take their energy directly from the sun’s rays. They absorb the sun’s energy and convert it into chemical energy. This is photosynthesis, the building of molecules using light energy. These organisms include plants, but of greater significance globally and historically are the algae and bacteria, single-celled organisms that form the basis for the ocean’s food chains.
The second group is the heterotrophs. Those organisms gain all of their energy in chemical form from the autotrophs, either directly in the case of herbivores or indirectly in the case of carnivores and detritivores.
The point is that all organisms are limited by their energy needs.
Only one organism seems to have broken free from the limitations imposed on them and only one species whose energy consumption knows no bounds. Humans have broken free of the shackles with fire and fuel and, in doing so, have shaken the natural world to its foundations.
But the truth is that having come this far, we can no longer live without excessive energy consumption, at least not in the manner to which we have become accustomed. Where going back appears impossible. Pandora’s box, once opened, can never be closed. So, we have a situation where the energy we require destroys our future, and living without energy is a future we cannot face.
And yet the availability of energy is not the issue.
It is simply the management of energy transformations that holds us back. In a single hour, the amount of power from the sun that strikes the Earth is more than the entire world consumes in a year.
The solution to our problems is freely available, 100% clean, and will never run out. Whether it’s wind, wave, solar, or hydroelectric, all we have to do is capture it, transform it and use it to transform our world before it’s too late.
Dan Heppner writes regular pieces for Medium. Make sure to follow him right here. He lives in the City of Worcester, England with his wife and family and is writing and thinking about science, ecology, and teaching.
