Lesson video

Hello, my name's Mr. Marsh and I'm here today to teach you all about developing unconventional oil and gas sources in sensitive or remote areas.

So grab everything that you need for today's lesson and let's get going.

So by the end of today's lesson, you will be able to explain the environmental costs associated with developing unconventional sources of oil and gas, oil from tar sands and gas from shale.

There are two key terms for today's lesson and those are unconventional and water quality.

Unconventional refers to sources of oil and gas that are relatively difficult to extract because the oil and gas is trapped and cannot flow freely towards an oil well or a gas well.

Water quality refers to whether what is in a supply of water, for example, its chemical or biological contents, make it suitable for a particular kind of use.

There are two learning cycles for today's lesson.

We're gonna start with learning cycle one, which is all about what are the costs of developing shale gas? Unconventional sources of oil and gas are much more difficult and costly to extract than conventional sources.

Now, on the screen in front of you then, we can see a brilliant illustration showing how conventional gas and oil sources are actually tapped into.

Conventional oil and gas is able to flow through porous rock to a well.

And now porous rock basically means rock with really minute spaces for that liquid or that gas or that oil to penetrate and flow through.

Shale gas, however, is trapped inside pores in shale.

Tar sands are made of bitumen, which are mixed with sand.

In order to extract that oil and gas from shale rocks, there is a process called fracking.

And this is a process by which gas and oil is actually extracted from the shale rocks.

And this is the process in which it happens.

So a well is drilled vertically and then horizontally into a layer of shale rock.

A mixture of water, sand, and chemicals is pumped into the well at high pressure.

This creates small cracks in that rock, allowing trapped gas or oil to actually flow out of it.

And finally, the sand keeps the cracks open so the gas or oil keeps flowing out into the well.

So a quick learning check.

It says: Why is shale gas an unconventional source of energy? You can see you've got three options on the screen there.

What you need to do is pause the video here whilst you read through those options and then select what you think is the correct answer.

And the correct answer was C, because it's trapped in shale rock formation.

So really well done if you were able to identify C as the correct answer.

Our next learning check says to identify the correct order for the fracking process.

Now once again, you can see you've got four different options on the screen, A, B, C, and D.

You need to put these into the correct order for how the fracking process actually happens.

So please then pause the video here whilst you consider and then select your answers.

And the correct order we were looking for is beginning with D, a well is drilled vertically and then horizontally into a layer of shale rock.

Then A, a mixture of water, sand, and chemicals is pumped into the well at high pressure.

Then C, this creates small rocks in the rock, allowing trapped gas or oil to flow out.

And finally, B, the sand keeps the cracks open so that the gas or oil keeps flowing out into the well.

So really well done if you too were able to get that correct order.

Unfortunately though the fracking process has many, many different environmental costs, including air pollution, climate change as a result of that air pollution, earthquakes, land use, and finally water contamination.

And we're gonna spend the next part of this lesson really trying to understand those different environmental costs.

So let's now have a look at those different environmental costs beginning with air pollution.

Because methane, which is a greenhouse gas, can escape from wells and toxic chemicals in stored fracking water can actually evaporate into the atmosphere.

Methane, as I said previously, is a greenhouse gas and adds to climate change if it leaks from wells.

What in terms of land use then? Well, although each fracking well pad only takes up a small area, when there is a lot of fracking wells, the impact is significant on that land.

In terms of earthquakes then, well, fracking can actually trigger or cause small or minor earthquakes.

This satellite photo shows an area of South Texas in USA and each of the pale coloured boxes that you can see on that image in front of you is actually a fracking well pad.

And you can really see the large quantity as well as their distribution on that satellite image.

Storage pits for water used in fracking can also be seen, as you can see on the left hand side of that image.

These are called impoundments.

When an area has a lot of fracking, the impact on land use can be significant, especially in ecologically sensitive areas.

Water contamination is also a really big environmental risk of fracking because fracking uses a lot of water, which is mixed with chemicals that can be toxic.

Now if these chemicals leak from perhaps faulty wells or are spilled at the surface, there is a risk, a real risk to water quality.

Now leaks can contaminate ground water, it can harm wildlife and it can actually cause health problems for nearby settlements and people.

So a quick learning check.

It says true or false? Fracking only uses water which means its environmental impacts are harmless.

So please then pause the video here whilst you consider and then select your answer.

And the correct answer was false.

Now, once again, I'd like you to pause the video here whilst you consider as to why that statement then is false.

And the reason it's false is that in fact, fracking fluid includes toxic chemicals and sand as well as water, which can have serious environmental impacts on water quality if spilled or released during the fracking process.

The wastewater left over from fracking also needs to be stored carefully.

So really well done if you were able to get those two answers correct.

Our next learning check says to add in the two missing environmental costs.

Now before we looked at five different environmental costs, and you can see that three are mentioned in front of you.

There are two missing though.

What you need to do is pause the video here whilst you try to recall those two pieces of information.

And the two correct answers we were looking for were land use and earthquakes.

Really well done if you were able to recall those two pieces of information.

We're onto our two practise tasks now for our first learning cycle.

And the first one says to list the potential environmental costs of developing this location on the screen in front of you for shale gas extraction, otherwise known as fracking.

And the second question says, explain which of these risks would be in your view the most significant.

So please then pause the video here whilst you attempt these two practise tasks.

Best of luck.

In terms of feedback then, for the first question, your answer may include the following: So we have air pollution, climate change, earthquakes, land use, and finally water contamination.

These are all potential environmental costs of developing this site on the screen in front of you for fracking.

The second question then, one possible answer could be the following: In my view, water contamination would be the most significant risk.

The chemicals used in fracking can be toxic.

And if these get into the groundwater from cracks in the well or are spilled at the surface, then there are risks to wildlife and people living nearby.

Another possible answer though could be: In my view, climate change is the biggest risk because it causes environmental damage at a global scale.

Fracking risks releasing methane into the atmosphere, which is a powerful greenhouse gas.

And burning shale gas for energy produces carbon emissions too.

So really well done if you are able to include anything like that in your own answer.

We're on now to our second and final learning cycle, and this one is all about what are the costs of developing tar sands? Tar sands are an unconventional source of oil.

Water and bacteria can change oil into bitumen, a thick and sticky substance.

It is similar to the tar used for road repairs.

Tar sands are a mix of sand, clay, water, and as I said previously, bitumen.

Separating the bitumen from the sand and clay takes a lot of energy and the bitumen can then be refined into different grades of oil.

It's time now for a learning check, and it says: which of the following is extracted from tar sands? You can see you've got three options on the screen there.

What you need to do then is pause the video here whilst you consider and then select your answer.

And the correct answer was A, bitumen.

So really well done if you were able to get that answer correct.

Some tar sand deposits are really deep underground and some are actually near the surface.

The process for extracting the oil differs in very different ways.

So the first then is looking at underground mining, because wells are drilled into the tar sand deposit, steam is then injected to heat the bitumen so it can actually then flow more easily.

The bitumen can then be pumped up to the surface.

What about surface mining then? Well, vegetation and soil is first removed.

Heavy machinery is used to dig up the tar sand and deposit it into trucks.

In a processing plant, the tar sand is mixed with hot water and chemicals to then separate the bitumen.

The bitumen in both of these sort of scenarios can then be refined into crude oil, which can then be used for our energy needs.

Time once again for a learning check.

And it says: what type of tar sand extraction do you think is occurring at this location? So you can see on the right hand side, you've got a satellite image and then you've also got an aerial photo of tar sand extraction in Alberta in Canada.

On the left hand side then, you can see you've got two different options, A and B, A: underground tar sands mining and B: surface tar sands mining.

So what you need to do right now then is pause the video here whilst you consider and then select your answer.

And the correct answer was B, surface tar sands mining.

Really well done if you were able to get that answer correct.

Now, just like fracking that we saw in learning cycle one, developing tar sands also has some really significant environmental costs, those being deforestation and habitat loss, climate change, air pollution, water use, and finally water contamination.

And once again, we're gonna try to understand each and every one of these.

So a quick learning check, it says: which of the following is an environmental cost of fracking but not of tar sands extraction? So you've got on the screen there four different options.

What you need to do then is pause the video whilst you consider and then select your answer.

And the correct answer was C, earthquakes.

Really well done if you were able to get C as the correct answer.

So let's start by looking at deforestation and habitat loss.

Because surface mining is the most common form of tar sands extraction.

Surface mining removes vegetation and soil and this can be done over an extremely large area.

In Alberta, Canada, as we saw previously on that previous slide, surface mining has cleared an area of 140,000 kilometres squared.

In Alberta, taiga forest has been cleared for tar sand extraction and this means habitat loss for a wide range of ecologically important species, including moose, bears, wolves and caribou.

Now on the right hand side you can see an example of the food web from Canada in the taiga.

And clearly, what we can see is that any effect on any animal within that food web would also have a knock on effect to the other species around it.

And what about climate change? Well, extracting the bitumen from tar sands is really energy intensive.

Natural gas is used to heat water to extract the bitumen, and burning gas actually releases carbon dioxide.

Now this is going to release greenhouse gases into our atmosphere, which is then driving climate change.

Underground tar sand mining has particularly high energy costs because it requires boiling water.

The huge trucks used to transport tar sands also have high carbon emissions.

In remote areas, oil then needs to be transported long distances to market, once again, releasing more carbon emissions.

Tar sand extraction actually releases 30% more carbon emissions than conventional oil extraction.

And this is another contributor towards climate change, which is of course affecting us on a global scale.

Time for a learning check.

And it says true or false? Extracting unconventional sources of energy costs more economically, but extracting conventional fossil fuels produces higher carbon emissions.

So what you need to do right now is really read back through that statement and consider whether this is true or false.

And the correct answer was false.

Now once again, I'd like you to pause the video whilst you consider as to why or how that statement is false.

And the reason it's false is that although it is true that extracting unconventional sources of energy can be more expensive economically than conventional oil or gas, extracting oil from tar sands also emits around three times as much carbon as extracting oil from conventional sources.

So really well done if you were able to get those two answers correct.

What about air pollution? Well, extracting bitumen from tar sands releases chemicals and tiny particles into the air, which can be really harmful to people's health.

Recent studies have indicated that tar sand processing in Canada can produce air pollution levels that are 60 times worse than for other industries.

In Alberta, many First Nations communities, which are the indigenous peoples of Canada and other regions in Canada in this example, live in tar sand areas.

These communities have been raising concerns about air pollution for many, many years because of the obvious implications for their health.

And what about water use? Well, extracting bitumen from tar sands requires a huge amount of water.

And our estimates for water use include the following: The fact that 2.

8 litres of water is needed to extract just one litre of bitumen using underground tar sand mining.

28 litres of water are needed to extract one litre of bitumen using surface tar sands mining.

This very high demand for water really puts stress on ecosystems and can put ecosystem health at risk, especially in sensitive areas, for example, in water-stressed areas.

This risk is reduced by water recycling.

And currently up to 95% of water used in extraction is actually recycled.

So it's trying to limit the amount of environmental cost caused by the extraction of bitumen.

Water contamination is a significant environmental consequence of developing tar sands because the water used to extract the bitumen becomes contaminated by toxic chemicals, which is actually used in the extraction process and this really does affect water quality.

Now on the screen in front of you on the right hand side, you can see a satellite image of a tailing pond in Fort McKay in Alberta, Canada.

And this one has an area of three kilometres squared.

But what is a tailing pond? While a tailing pond is where this toxic water is actually stored.

In Alberta, these cover a total area of 220 kilometres squared and store 1.

2 trillion litres of contaminated water.

There is a clear risk of harm to health for wildlife that drink from these tailing ponds.

And the tailing ponds can actually leak and the contaminants can pollute rivers and groundwater and thereby affect further wildlife and perhaps even people as well.

Time once again for a learning check.

And it says which two environmental costs of developing tar sands are missing from this diagram? So we looked at this previously in this learning cycle where we looked at five different environmental costs.

Two are missing.

What I need you to do then is try to recall that piece of information to complete those two different environmental costs.

So please then pause the video here whilst you attempt this learning check.

And the correct answers were deforestation and habitat loss and the second one was water contamination.

So really well done if you were able to get those two answers correct.

We're on now to our two practise tasks for our final learning cycle.

And the first one says to study this satellite image of Fort McKay Alberta in Canada, suggest two possible local environmental costs of tar sand extraction and processing at this sensitive location.

The second one says to study this satellite image of Canada and the GIS layer showing biomes.

I would like you to explain two ways in which developing tar sands in Alberta could have really devastating environmental costs on a global scale.

So please then pause the video here whilst you attempt these two practise tasks.

Best of luck And now some feedback.

So your answer to the first question may have included the following: I've said that this location shows surface tar sands extraction and processing that affects an extensive area of 40 kilometres wide.

I can see large tailing ponds.

So one possible environmental cost would be water contamination.

For example, leaks of the toxic water in the tailing ponds into the Athabasca River.

A First nations town, Fort McKay is very close to the tar sand surface mines.

Tar sand extraction produces high levels of air pollution.

And so a second environmental cost could be health impacts of air pollution affecting the indigenous people of the local area.

The second question, then, once again, your answer may have included something like this.

I said that extracting and processing oil from tar sands emits around 30% more carbon than extracting oil from conventional sources.

That means that developing tar sands in Alberta contributes significantly to climate change, which is an environmental cost at a global scale.

Surface mining of tar sands is widespread in Alberta with 140,000 kilometres squared of taiga vegetation cleared to date.

Deforestation on that scale is a global problem and it means the loss of globally important habitat in the taiga biome with its amazing wildlife, such as moose, bears, and caribou.

So really well done if you were able to include anything like that in your own answer.

We're on now to our learning summary and what you need to know from today's lesson.

Well, we need to know that unconventional sources of oil and gas are more difficult and costly to extract than conventional sources.

Developing shale gas and tar sands both have a wide range of environmental costs, including impacts on water quality due to the methods of extracting unconventional gas and oil.

These gas, these costs, I should say, are potentially even higher in ecologically sensitive areas.

So really well done during today's lesson.

It was a pleasure teaching you and I will see you again on the next lesson.

Goodbye.