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.
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.
For resources in addition to those featured below, see Lesson 2.4—Energy and Carbon.
Energy is essential to life and all living organisms. The sun, directly or indirectly, is the source of all the energy available on Earth.
Carbon and Climate Change in 90 Seconds
Energy powers all living systems and this NASA video shows how energy flows from the Sun, to the Earth, through humans, and through the technology humans use.
Video length: 2:21 min.
The Ocean's Green Machines
Phytoplankton, a tiny marine plant, makes life on Earth possible. It forms the basis of the marine food web and regulates carbon in the atmosphere. Warming waters have consequences for phytoplankton and for the planet.
Video length: 5:35 min.
Striking a Solar Balance
Earth's climate depends on energy from the Sun. The Total Irradiance Monitor on NASA's Glory mission will continue measuring solar irradiance, which will contribute to the long-term climate record.
Video length: 3:36 min.
Energy Issues—Foundations of Life: Switch Energy Project
Energy drives the modern world and underpins every other issue.
We choose our energy based on four attributes: affordable, available, reliable and clean. But defining clean is complicated. All energies have environmental impacts that need to be managed effectively and affordably. Even so, the biggest challenge of energy is scale—the enormous amount of energy we demand. And the only way to counter scale, is with efficiency.
Video length: 2:12 min.