ENVR 103, energy Energy Main points Many forms of energy are available to meet human needs, but most can be traced back to solar radiation striking the earth from the sun. The other primary source of energy on the planet comes from the decay of radioactive materials.
Humans require energy to support life processes, like all other organisms.
Historically our use of new and additional energy sources was critical for our technological development. Energy can be divided into renewable and non-renewable energy sources. Utilizing non-renewable energy sources leads to some degree of depletion of these resources. Renewable energy resources are replenished by natural processes on a time scale consistent with how fast they are used. The utilization of these resources therefore does not substantially deplete them.