- [Instructor] Today, let's talk about energy resources.
You've probably already done something today
that used energy resources,
even beginning from the moment you woke up.
For me, the beginning of my day
always starts with making tea.
I use energy in every step of this process.
My car uses oil when I drive to the grocery store
to get the tea,
my stove uses natural gas when I boil the water,
and my water heater uses coal-sourced electricity
when I wash my mug in hot water afterwards.
We use energy constantly in our daily lives.
Since the first law of thermodynamics
states that energy cannot be created nor destroyed,
where does it all come from and will we have enough?
When we talk about energy resources,
we could split it up into two groups:
renewable energy and nonrenewable energy.
I can always remember what renewable resources are
because the prefix re means again
and the root new refers the origin of the energy source,
so renewable energy sources
are the sources that we can use again and again
and are quickly restored by natural processes.
Renewable fuel sources include sunlight, wind,
moving water, biomass from fast-growing plants,
and geothermal heat from the earth.
The lifespan of renewable resources looks like a circle.
We can use them and then we can use them again
without worrying about them running out.
Nonrenewable energy sources on the other hand,
are sources that exist in a fixed amount
and cannot be easily replaced.
These energy sources must be extracted from the earth,
and they include things like nuclear fuel and fossil fuels,
which are things like coal, oil, and natural gas.
Fossil fuels were formed in the geologic past
from the remains of ancient organisms.
Plants and animals that died millions of years ago
became buried in the soil, partially decomposed,
and were exposed to a lot of heat and pressure.
This heat and pressure chemically rearranged
the energy contained within their bodies
into the fossil fuels we use today.
Because they take so long to form, we have a finite amount
of nonrenewable resources in the earth right now.
The lifespan for fossil fuels is a broken loop,
a one-way ticket.
First, the fossil fuel is found,
then it has to be extracted.
Extracting fossil fuels
can involve destructive mining processes
that can pollute surrounding habitats.
It then has to be transported to wherever it will be used.
And using fossil fuels means burning them,
which releases greenhouse gases
and other pollutants into the atmosphere.
Also, it can take energy
to refine and process some types of fossil fuel
so that they're more helpful to us,
like turning crude oil into petroleum gas,
diesel, and jet fuel,
and burning the fossil fuels transforms that energy
into a less organized form of energy like heat and ash.