Earth Resources and Human Impact

Question 1

why should we care about the earth?

Answer 1

We use things – materials – resources –non-renewable
We consume energy, both renewable and not
We experience costly disasters– volcanic eruptions, earthquakes, tsunamis
We are curious/concerned about our past/future environment, climate

Question 2

what is the history of resource use by humans?

Answer 2

Stones: hunting, fishing (e.g.flint/obsidian arrowheads)
Salt: extensively traded, valuable
Metals:
- Native metals (Cu, Au, ..) since ~17 ka: ornaments, weapons, tools, utensils
- Metals extracted from minerals by smelting since ~6 ka
- Alloys produced since ~5 ka, e.g. bronze, pewter
Fuel:
- Oil since ~4.5 ka (Babylonians)
- Coal, natural gas since ~3.1 ka (China)
Secondary products: cement, glass, porcelain, plaster –produced by Greek & Roman civilisations

Question 3

what do the components for an iPad require?

Answer 3

pure-silica sand deposit (glass); salt mine (Na); rock quarry (Ca); oil well (plastic); aluminum mine; iron mine; manganese mine; copper-molybdenum-gold mine; rare-earth element & indium mine; energy to process, transport, assemble materials, transport to consumer

Question 4

how much more copper does a hybrid car use than a similar car?

Answer 4

twice as much

Question 5

what rare chemical elements are critical to smartphone performance?

Answer 5

Lithium -batteries
Europium and erbium - used in screens
Tantalum- for use in smaller capacitors
Neodymium and Tungsten – critical to ‘vibrating alert’ function
Lanthanum- a key component that lengthens battery life

Question 6

Where does food get its nutrients?

Answer 6

Food consists of essential nutrients and metals: sodium (Na), potassium (K), phosphorous (P)
Elements derived from soil used to grow food
Soil comes from rock (100’s of years to form)
All the Na, K and P in a cheeseburger = 18 g of gran