Fossil Fuels


Hi. It’s Mr. Andersen and this is AP environmental
sciences video 24. It is on fossil fuels. We really do live in the age of fossil fuels.
Most of the energy that I am using and you are using right now is probably coming from
coal, oil and natural gas. And I have grown up around gasoline stations like this Sinclair
station. I remember thinking as a kid that fossil fuel meant that the fuel had to come
from the bones of ancient dinosaurs. It could come from that if that if that dinosaur was
stranded in an ancient ocean and was fragmented and deposited on the bottom of the ocean with
billions of microscopic plants and animals. And then quickly covered by sediment and then
heat and pressure were to squeeze it anaerobically to make oil and gas. But that is probably
what did not happen to most dinosaurs. Regardless, fossil means coming from once living material.
And it is formed anaerobically in an area underneath the earth where there is not oxygen
available for decomposition. It comes in three different types, solids, liquids and gases.
We have coal, petroleum and natural gas. Coal is formed when we have a swampy area that
over time is forested areas covered with sediment. We squeeze it. We remove a lot of the moisture
and then over time heat and pressure forms peat. And then lignite and then forms of different
types of solid coal. And we can simply combust this and we get a lot of energy out of it.
If we are looking at petroleum, crude oil is probably what you are most familiar with,
we pump that liquid out of the ground. And we can also take solids like oil sands and
oil shale. We can mine that and process it to make this liquid. And then finally we have
natural gas, which is going to be methane. Now all forms of fossil fuels are going to
have advantages and disadvantages. The big advantage of all of them is that they have
a huge amount of energy. The big disadvantage is the environmental impacts they are having
on our planet. There are impurities found that are released into the atmosphere. So
we have air pollution. Sulfur dioxide is an example of that. And then more importantly
we are putting carbon dioxide into the atmosphere which is leading to global warming. And then
finally they are nonrenewable. They are unevenly spaced on our planet and they are finite.
We are going to run out of fossil fuels over time. But right now it is the fuel of choice.
Oil, coal and natural gas is where the world is getting its energy. A little bit is coming
from nuclear. A little bit is coming from renewables and a lot of that is actually coming
from wood. But if we are to look at how they are formed, coal is formed where we have a
swampy area. It is covered over time. And as we squeeze it over time it forms something
called peat. We can actually combust that but we do not get as much energy. Over time
more heat and pressure can squeeze the moisture out. We are left with more of the carbon.
It forms something called lignite. And then it can form something called coal overtime.
But we can have different grades of coal. More impurities or less impurities. One of
the most pure is called anthracite. And it is just essentially all carbon and burns fairly
clean. So how do we use coal? You simply dig it up on the surface, on these huge strip
mines and sometimes underneath the surface. Then we move it where it needs to be. And
then we combust it. It generates a huge amount of steam and then we can generate electricity.
This is a huge power plant down in Utah. What are some advantages of it? It is super cheap.
It is easy to dig it up. We get a huge return on our investment. It is plentiful. It is
going to be found in lots of countries on our planet. And it is easily mined. What are
some disadvantages? It is really dirty. It has a huge amount of impurities in it. Some
coal will have up to four percent sulfur and that releases sulfur dioxide into the atmosphere.
We also have a lot of the ash that is left behind when we combust it. So we have to store
that. And then finally it is increasing carbon dioxide in the atmosphere. If we look at the
petroleum, how is that formed? It is formed in these ancient oceans where we have microscopic
life being deposited on the ocean floor. It is covered with sediment. And then over time
that sediment puts more heat and pressure. It is now covered so it is in an anaerobic
environment. And we eventually form oil. And a lot of the time we will have natural gas
bubbling up to the top. And so how do we get it out? We simply dig down and we pump that
oil out of the ground. That crude oil is then refined. So we will ship it to a refinery.
We can heat it and we can get things like diesel, petroleum, gasoline, fuel oil, depending
on how we process it. Now another form of petroleum are the oil shales and the oil sands.
So they are a solid. But we can mine that. We can process it. And we can make a liquid
fuel. And that is one of the big advantages of petroleum. It is a liquid and so we can
move it where it needs to be. And it is also super important in transportation. It works
really well in your car. It is energy dense, more energy dense then we are going to find
in coal. And it is actually a little bit cleaner than coal. Less impurities. Less carbon dioxide
per amount of energy that we are producing. What are the problems? It still has some impurities
in it. And also since it is moveable we are more likely to have accidents. So oil spills
for example as we move that oil around. And then finally it is a greenhouse gas. It is
putting carbon dioxide into the atmosphere. If we look at natural gas it is simply methane
gas. We burn it and we can get energy out of it. One of the big advantages of natural
gas is we can use it in heating. It is cleaner than oil and coal. Some people call in the
clean fossil fuel. It has lower carbon dioxide per amount of energy that is being used. What
are some of the disadvantages? It is methane which is a huge green house gas. So if some
of that is released it gets into the atmosphere and causes global warming. The exploration
of finding natural gas is going to destroy sediment a lot of the time. And then actually
taking it out, a big process they are now using is hydraulic fracturing, where we are
squeezing fluids into the crust and that can lead to earthquakes and also contamination
of the water table. If we look at big environmental impacts, the big one is the amount of carbon
dioxide in the atmosphere. So if we look at the amount of carbon being pumped into the
atmosphere world wide, you can see it is increasing over time, exponentially. Where are the big
culprits? It is going to be coal, oil, natural gas and actually the processing of cement
or making of cement is a huge greenhouse gas emitter as well. Aside from environmental
impacts, they are nonrenewable. This is the Hubbert curve. And what we are looking at
is as we discover something like oil in Texas or in the US or in Norway for example, we
will extract a lot of it but eventually it is going to drop off over time. And so we
have what is called peak oil. In other words we are not going to harvest anymore oil. If
we look at how that idea of the Hubbert curve works with the amount of oil that we are getting,
we will see that it does not necessarily match up. This is that Hubbert curve of peak oil.
But this is the actual oil, crude production. And the reason why it is not peaking off is
because we are discovering new ways of finding oil. If we look at where the fossil fuels
are formed, again thinking about how coal is made, it is going to be in areas that are
massive and have lots of forested regions. And so the biggest oil reserves are going
to be found in the US, Russia and China. China is actually using coal more than any other
country at this point. If we look at oil reserves, most of these are going to be in the middle
east so Venezuela, Saudi Arabia, Canada. But then we go to Iran, Iraq, Kuwait. That is
where most of our oil is going to be found. And then if we look at the gas reserves, we
are going to have gas in Russia, Iran, Qatar. But a lot of this again is going to be found
where the oil is. It is going to be found in those Middle Eastern countries. And so
did you learn the following? Could you pause the video at this point and fill in the blanks?
I will do it for you. Fossil fuels are formed in an anaerobic environment. Coal is formed
where we have vegetation squeezed to make peat, then lignite, then coal. Petroleum can
come in the form of crude oil or oil sand or oil shales. We are looking at natural gas,
that is methane. There are advantages and disadvantages of each. The big ones are environmental
impacts, especially carbon dioxide. And then the idea that they are nonrenewable. We have
reserves that are found on our planet, but they are finite and we are going to run out
of those and we are going to have to move towards renewable resources. So I hope you
learned all of that and I hope that was helpful.

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