Energy is essential to life and all living organisms. The sun, directly or indirectly, is the source of all the energy available on Earth. Our energy choices and decisions impact Earth  natural systems in ways we may not be aware of, so it is essential that we choose our energy sources carefully. The true cost of energy is more than just dollars and cents; there are important economic, political and social factors and consequences to consider as well. 

Energy Powers All Living Systems

Nearly everything eats sunshine – or eats something else that ate sunshine. The Sun is the major source of energy for organisms and the ecosystems of which they are a part. Producers, such as plants and algae, use energy from sunlight to make food energy by combining carbon dioxide and water to form organic matter. This process begins the flow of energy through almost all food webs. 

1. Food is sunshine stored in chemical form. Organisms use the stored energy in food to fuel all living processes. Food is organic molecules that serve as fuel and building material for all organisms. The breakdown of food molecules enables cells to store energy and to carry out the many functions of the cell and therefore the entire organism.
2. Human Energy Use Impacts Natural Systems  Humans rely on sunshine (and stored energy), too. Humans are a part of—not apart from— Earth’s ecosystems. Humans influence energy flow and are modifying the energy balance of Earth’s ecosystems at an increasing rate. 
3.  Energy and Economic Circumstances  Generally, people with lower incomes have less financial influence over where their energy comes from. Similarly, people with higher incomes have greater influence financially over energy choices and, by voting with their dollars, they impact the type of energy available to society as a whole.
4. Energy and Political Factors Governmental structure and power balances, actions taken by politicians, and partisan-based or self-serving actions taken by individuals and groups.
5.  Energy and Social Impacts Energy decisions are influenced by social variables, such as beliefs, values, attitudes and

   knowledge.

Essential Energy Information, Concepts, and Themes

1. Energy flows through food webs in one direction, primarily from the sun to producers then to consumers and, finally, to decomposers.
2. Energy comes in many forms. It can be converted and stored.
3. Energy conservation does not mean decreased quality of life, but often leads to improved quality of life through increased economic and national security, reduced environmental risks, and monetary savings. The way humans use energy has lead to rapid climate change across the planet.
4. Humans harness energy from any available resource and the demand for energy is ever increasing. Earth has limited energy resources. Renewable energy provides countless opportunities for economic growth, job creation, improving quality of life, and much more.