Science & Technology in Action

12th Edition

Resource efficiency


Agricultural Science
Today we face potential shortages of food, water, fuel, timber and critical materials. Historical events have been driven by drought, famine and climate events, and continue to be. Our current wasteful use of the limited available resources cannot be sustained.
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Lesson excerpt

Resource efficiency 
Human intelligence allowed the development of civilisations. Knowledge grew and people developed an ability to exploit the environment in a way denied to other species. Economies developed according to a linear model where resources were obtained, products were manufactured and were ultimately disposed of. The supply of resources seemed limitless while the human population was small. 

Today we face potential shortages of food, water, fuel, timber and critical materials. Historical events have been driven by drought, famine and climate events, and continue to be. Our current wasteful use of the limited available resources cannot be sustained. 

Travelling to Mars 
In recent years there has been much publicity about a proposed manned mission to Mars. It would be a one-way trip, mainly because it would be virtually impossible to bring along a second rocket large enough to make the return journey. 

The outward journey would take several years during which the astronauts would need food, water and oxygen. The only realistic way the crew could get these essentials would be to recycle them. They would need to grow the necessary food and recycle all waste. With only a limited amount of materials they could not afford to waste anything. 

Spaceship Earth 
The Earth is a somewhat larger spaceship. It travels around the Sun at a speed of almost 30 kilometres per second! (You can easily work this out.) The supply of resources such as food, water, fuel and minerals is not limitless. We are already running out of certain materials and fossil fuels and as a result there is a growing realisation that we need to use the available resources more efficiently and sustainably. 

True or False?

  1. New skills and technologies will be needed to properly embrace the circular economy. true
  2. Using wind as an energy source involves no environmental degradation. false
  3. Miniature electronic components are easy to repair and recycle. false
  4. Rainwater harvesting is a very recent invention. false
  5. Whether a material is critical or not depends on a combination of factors. true
  6. It is possible for renewable food sources to be over-exploited. true
  7. Large amounts of plastic have got into the oceans. true
  8. Worldwide, less material went to landfill in 2016 than 10 years previously. false
  9. Communities around the world have suffered from water shortages. true
  10. Deforestation has no environmental or economic consequences. false

Glossary of terms

drip irrigation
an irrigation system in which pipes bring a trickle of water to the roots of plants
CH4; a chemical compound made up of carbon and hydrogen; used as a fuel; the main component of natural gas; also produced as a by-product of anaerobic sewage treatment
methane produced by the decomposition of biological material (biomass) such as animal slurry
the number and variety of organisms found within a specified geographic region
The process of growing plants in water supplied with nutrients, but without soil
typically, material of biological origin that can be used directly or indirectly as a fuel
using a resource that can be renewed
biological nutrients
substances that provide living organisms with materials necessary for energy and general living processes
circular economy
an economy in which all materials are recycled
refers to online computer resources
companion planting
planting of different crops in neighbouring rows or patches for better pest control, pollination, biodiversity, use of space etc.
critical materials
materials that are not readily available but are necessary for the economy
European Nitrate Directive
an EU directive to improve water courses by limiting the amount of nitrate run-off
green rooftops
using rooftops to grow plants
linear model
a production model in which there is little or no recycling
plastic particles that are generally smaller than 1 mm; sometimes added (as microbeads) to cosmetics etc.
passive heating and cooling
heating or cooling without mechanical devices such as pumps, fans etc
precision farming
the use of GPS and satellite technology in agriculture to determine correct fertiliser levels, growth etc
primary producers
photosynthesising plants
rainwater harvesting
collecting rainwater
resource efficiency
making efficient use of available resources
smart farming
reducing farming costs through better resource management
technical nutrients
a nutrient that can be used again and again, i.e. can be recovered and recycled
winter crops
crops that grow over the winter