Articles on this site are classified under various main categories:
- Challenges - the physical limits and other challenges to the sustainability of human life on earth
- What is energy?
- how much do we use and for what?
- how is energy consumption related to poverty and development?
- how does our energy mix need to change to become sustainable?
- Renewable energy - with index of pages on the subject
- Nuclear energy - with index of pages on the subject
- Carbon Capture and Storage (CCS) - with index of pages on the subject
- People - who's who
- Action - what we can do, individually and/or collectively, about the problems we face
Articles are also classified with a quality rating:
Numeric codes indicate the quality of articles:
1 Pages comprising collections of links and excerpts,
2 Pages with paragraph(s) of introductory discussion, with collections of links and excerpts for at least some of the remainder of the piece,
3 Pages written in full discussion style with links to and excerpts from external materials in references and further reading sections.