Human Energy Use

Do Now:

Define: Energy

Where does most of the energy used by humans come from?

Energy

• Physics: The ability to do work (=Fd)

• General: The ability to cause change.

• Units: Joule (SI) Calorie (English) kCal (dietary calorie

• Laws of thermodynamics:– 1: Energy cannot be created or destroyed– 2: No transformation of energy is 100%

effiicient (entropy increases in a closed system)

Human Energy

• 80-90% of the energy used by Homo sapiens is produced by the combustion (oxidation) of fossil fuels…

It all started waaaaaay back…

The energy stored in the fossil fuel we use today was first captured by plants millions of years ago.

Geology Takes a Turn

Coal formationOil & gas accumulation

Getting it out of the ground

Offshore oil rig

Open pit coal mine

Crude Oil is Organic Chemicals

There’s thousands of different chemicals in oil that comes out of the ground.

The different parts or

“fractions” must be

separated before

they’re used

Oil Refinery

What about coal?

The combustion of coal produces more CO2 than equal amounts of any other fossil fuel

Most Coal is Used to Produce

Electricity

What Homo sapiens Use Energy To Do

Consequences

Humans have consumed more crude oil than they have discovered for over 20 years now.

Metabolism with Global Consequences

Human Population Growth

The Effect of Resource Depletion and Toxin

Accumulation on a Population

What to do?We must begin using less energy – whether

we want to or not.

Life on Earth has relied on the sun’s light as it’s primary energy source for

billions of years.

Solar Panels: 2 designs

Our technology is what truly makes our species unique on Earth. Use the best brain and hands that evolution has ever produced to make a difference.