Population Matters

Energy & materials

Energy & materials

Humanity is entirely dependent on energy resources, notably fossil fuels. Other energy sources have uses but also limitations. The use of fossil fuels is increasingly constrained by their limited supply and environmental consequences, particularly climate change. Many other resources have a finite supply. Even renewable resources require careful management to ensure continued availability.


Ever more people means an ever increasing demand for energy. Almost all of the things we need and use depend on a single underlying resource — energy. Solar energy in the form of sunlight is essential for growing food. Unsustainable levels of energy consumption in the form of heat and power are an essential feature of all industrial economies, which use significantly more energy than developing economies.

The global demand for energy will be one third higher by 2040
The global demand for energy will be one third higher by 2040

Fossil fuels, i.e. oil, coal and gas, are the stored solar energy from hundreds of millions of years of plant and animal life. No other energy source is as versatile as oil or has so many uses. Oil is an essential component of almost all plastics and we are a long way away from electrically or nuclear powered jet aircraft. Some experts think we have already reached peak oil production, yet there is no easy substitute.

Alternative energy sources are polluting, as with coal, or they compete with food production for land, as do biofuels. Yet others are limited in scale, such as energy from water or waste derived biomass; or their availability is variable or unpredictable, as with wind and wave power. Some may also depend on other limited resources, as do gas and nuclear energy, which requires the use of uranium.

Even if some of these drawbacks can eventually be overcome, the investment required to replace present fossil fuel consumption with sustainable alternatives will be enormous.

Agriculture particularly depends on oil and natural gas for such things as irrigation, the production of fertilisers, the use of farm machinery to plant, fertilise, apply pesticide and harvest crops, as well as the transportation and preservation of crops. Food processing also relies on fossil fuels, as do delivery of additives, production and transportation of packaging and delivery of the finished products to retailers.

Despite a continual search for new solutions, an ever-increasing energy demand from an ever-rising population poses an ever growing and ultimately insurmountable challenge.

Read more about energy.


Ever more people need ever more materials. There are many examples of how growing demand is putting pressure on the supply of materials. As mineral deposits are depleted we are increasingly turning to harder-to-access, more expensive sources. Western society depends overwhelmingly on oil-based plastics, derived from this finite resource. Plant-based materials compete with food production. Building materials require quarrying which destroys the natural environment. And both increased logging and larger plantations degrade virgin forests.

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Some resources, such as rare minerals, are nonrenewable. Once they have been used up they are gone forever. Unfortunately, especially with mineral resources, conventional economics can be misleading about their abundance; more account is often taken of the human effort to extract them than of their value as nonrenewable geological resources. Economists treat revenues from the depletion of natural capital as income — “growth”. For instance, “increasing oil production” means “consuming even faster our dwindling stock of the most versatile and precious of our irreplaceable fossil fuels”.

Read more about materials, minerals and what the things we use are made of.


Many other resources are ‘renewable’ because they are naturally regenerated. But even these are not unlimited; we can only go on using them in the long term if we do not exceed the rate at which they are naturally regenerated. Unfortunately, it isn’t always obvious when we are over-using a particular type of resource, either locally or globally.

Human ingenuity has found all sorts of ways to overcome shortfalls in one resource by using more of another. For instance, developed countries use nonrenewable energy resources (oil and natural gas) to manufacture fertilisers in order to grow a larger amount of food than would otherwise be possible using genuinely sustainable methods of agriculture. When talking about sustainability, it is always necessary to see the bigger picture.

Next: Air, food & water

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