7.1 - Energy Choice and Security

3. is wood and charcoal used to supply energy.
4. Oil extracted from reserves, sometimes described as "tight oil" reserves, held in shales and other rock formation from which it will not naturally flow freely. Shale oil has become more accessible due to advances in technology.
7. Energy Sources finite, so as they are used up the supply that remains is reduced
9. Poverty a lack of access to modern energy services - a household's access to electricity and clean cooking facilities (e.g. to fuels and stoves that do not cause air pollution in houses).
10. Energy Sources can be used over and over again. There resources are mainly forces of nature that are sustainable and usually cause little or no environmental pollution.
11. Poverty when a low-income household is living in a home that cannot be kept warm at a reasonable cost.
12. Petroleum Reserves are large reserve of oil held by countries including the USA and China to tide them over for a few months or so if normal oil supplies are disrupted.

1. Gradient the rate at which temperature rises as depth below the surface increases.
2. replacing of initial turbines with modern turbines that produce more electricity.
5. political relations among nations, particularly relating to claims and disputes pertaining to borders, territories and resources.
6. production ratio the reserves remaining at the end of any year divided by the production in that year. The result is the length of time that those remaining reserve would last if production were to continue at that level.
8. Oil Production the year in which the world or an individual oil-producing country reaches its highest level of production, with production declining thereafter.