In 1962 Kardashev (1) came up with an interesting way of classifying civilizations according to the amount of energy used.
| Type I | the resources of a planet |
| Type II | the resources of a solar system |
| Type III | the resources of a galaxy |
The sun produces approximately 4*10^26 watts of energy.
The earth receives approximately 1.7*10^17 watts of energy.
Humans use approximately 12*10^12 watts of energy.
The forms of the energy humans use worldwide are:
| Oil | 37% |
| Coal | 24% |
| Natural Gas | 21% |
| BioFuels | 14% |
| Hydro | 2% |
| Nuclear | 2% |
These particular statistics come from Energy, A Guidebook , however similar numbers, plus or minus a few percent, are available from several sources, such as:
These percentages define the energy problem humans face. About 80% of the energy is derived from non-renewable fossil fuels which aggravate globalwarming .
The relevant questions are:
The goal here is to generate solutions, not despair.
"It is difficult for people living now, who have become accustomed to the steady exponential growth in the consumption of energy from fossil fuels, to realize how transitory the fossil fuel epoch will eventually prove to be when it is viewed over a longer span of human history. The situation can better be seen in the perspective of some 10,000 years, half before the present and half afterward. On such a scale the complete cycle of the exploitation of the world's fossil fuels will be seen to encompass perhaps 1,300 years, with the principal segment of the cycle (defined as the period during which all but the first 10 percent and the last 10 percent of the fuels are extracted and burned) covering only about 300 years."
Last modified February 24, 2008