The student will investigate and understand that there are basic sources of energy and that energy can be transformed. Key ideas include
1. the sun is important in the formation of most energy sources on Earth;
2. Earth’s energy budget relates to living systems and Earth’s processes;
3. radiation, conduction, and convection distribute energy; and
4. energy transformations are important in energy usage.

Central Idea: The major source of energy on Earth is solar radiation.

solar radiation and earth's Energy budget

All Earth’s processes are the result of energy flowing and mass cycling within and among Earth’s systems. The energy is derived from the sun and from Earth’s hot interior.

• Solar radiation is made up of different types of radiation (including infrared, visible light, and ultraviolet).

• Earth receives only a very small portion of the sun’s energy, yet this energy is responsible for powering the motion of the atmosphere, the oceans, and many processes at Earth’s surface. Earth’s surface is heated unequally.
• Earth’s energy budget refers to the tracking of how much energy is flowing into and out of the Earth’s climate, where the energy is going, and if the energy coming in balances with the energy going out.
• The Earth’s energy budget includes the solar energy entering and exiting Earth’s atmosphere. Excess carbon dioxide and other gases affect the energy budget, creating a greenhouse effect.

radiation and convection

Convection powers the circulation of the atmosphere and oceans
• When air or water is heated, the molecules move faster and farther apart, reducing their density and causing them to rise.
  • Cooler air or water molecules move more slowly and are denser than warm air or water.
  • Warm air or water rising coupled with cooler air or water descending forms a cyclic rising/falling pattern called convection
• Radiation and convection from Earth’s surface transfer thermal energy.
  • This energy powers the global circulation of the atmosphere and the oceans on our planet.

Energy Transformations

• Energy is continuously transferred from one place to another and transformed among various forms.
• Secondary sources of energy, such as electricity, are used to store, move, and deliver energy easily in usable form.
• Thermal and radiant energy can be converted into mechanical energy, chemical energy, and electrical energy and back again.