Geography of energy

What is energy, and why do we need it? In scientific terms, energy is the ‘capacity to do work’. The work may take a variety of forms:

• moving things (kinetic energy)
• lighting things (radiant energy)
• warming things (heat energy)
• altering the state of things

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Altering the state of things can include electrical energy, such as using electrical impulses to store and organise data, or chemical energy, such as using reactions to change or modify substances in the food or chemical industries. Indeed, altering the state of things might include a combination of energy types.

The less energy available to a society, the less ‘work’ (in the broadest sense of the word) it will be able to do and the fewer tools it will have available. Conversely, when a society has abundant supplies of energy, human ingenuity allows the society to engage in major works.

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The nature of these works varies according to the type of energy. Societies whose energy was limited to human muscle power achieved architectural monuments such as the pyramids using the energy of a large slave population.

As societies became more sophisticated in the energy sources they harnessed, their works became more varied. Manufacturing, medicine, transport, technology – and even art – in a society reflect the possibilities provided by the energy types and availability.

You can read more about early power sources in the following scene:

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We owe most of the luxuries we enjoy to the abundance of cheap energy sources, and particularly to fossil fuels, which store energy concentrated in the ground over millions of years. But these energy sources are not sustainable because they take tens of millions of years to form and we are using them hundreds of millions of times faster than they are replaced. Furthermore, the use of fossil fuels causes problems on a variety of scales.