Science & Technology in Action

5th Edition

The Energy Challenge


Fossil fuels are still available but will eventually run out. For many reasons alternative energy sources will be required to meet the future needs of a larger and more developed global population.

Contains the full lesson along with a supporting toolkit, including teachers’ notes.

Lesson excerpt

Today there is heightened concern about the future of energy supplies. There are several reasons for this.

  • Fossil fuels reserves are finite.
  • The cost of fossil fuels are likely to increase as they become less accessible.
  • The world’s population is increasing and more energy will be needed.
  • Energy requirements in developing countries will increase as living conditions improve.
  • Energy demand in developed countries is likely to rise rather than fall.
  • Some energy technologies have a negative impact on the environment (air, water and land).
  • Fossil fuels can be controlled for political purposes.

Likely Future Energy Requirements
In the absence of more coherent international agreements, global energy consumption is likely to follow the trends shown in the graph below. The world population is expected to rise from today’s figure of almost 7 billion to 9.5 billion by 2050. Extra energy will be needed to meet their needs, especially as they become more prosperous.

The Fossil Fuel Contribution (78%)
At present about 78% of global energy is derived from oil, gas and coal (31% + 21% + 26%). So-called ‘easy-oil’ reserves are being depleted and newly discovered ones are generally much less accessible. Global oil production is expected to peak by 2015 after which it will decline steadily; the extent of the decline is a matter of some dispute, but analysis suggests that it will drop to half its present level between 2050 and 2100. Gas production is expected to peak around 2025 and coal production around 2040. As fossil fuels run out, alternative energy sources will be increasingly required to meet the demand.

Quiz questions

  1. Less energy will be required in the future. false
  2. The world’s population is expected to be 9.5 billion by 2050. true
  3. Coal resources will be depleted by 2040. false
  4. At present about 80% of global energy is generated by fossil fuels. true
  5. One third of the global population uses less than 10% of global energy. true
  6. Nuclear energy is used to generate 80% of electricity in France (or about 40% of its total energy). true
  7. First generation biofuels are made by fermentation of straw and waste cellulosic material. false
  8. Today there seems to be little interest in constructing more large-scale hydroelectric schemes but there is considerable investment in numerous small-scale projects (< 00 MW). true
  9. Second generation biofuels are derived from food crops such as maize. false