Hello, geographers.

My name's Mrs. Formigo.

I'm going to be teaching you today.

I'm looking forward to it.

I hope you're going to enjoy the lesson and learn lots.

Let's get started.

Today's lesson looks at the effects of climate change.

Climate change has social, economic, and environmental effects.

By the end of today's lesson, you will understand how climate change affects people and the environment.

There are four keywords for today's lesson.

Extreme weather, when a weather event is significantly different from the average or usual weather pattern.

Social impact, the effect on people and communities due to an event or situation.

Biodiversity, a measure of the variety of living organisms within a particular habitats, ecosystem, biome, or all over Earth.

And food security, when people lack secure access to sufficient amounts of safe and nutritious food for normal growth and development and an active and healthy life.

There are three learning cycles for today's lesson.

Environmental impacts of climate change, impacts of climate change on people, and future projections for climate change.

Let's get started on the first one, environmental impacts.

An increased concentration of greenhouse gases in Earth's atmosphere is leading to a rise in the average global temperatures, and this is shown here on the graph.

You can see, as CO2 concentration increases, the global temperature also increases.

Rising temperatures are causing climate changes and an increase in extreme weather events.

These changes are having impacts on people, and the environment.

These are the main environmental impacts that this lesson is going to consider, declining in arctic sea ice, sea level rise, ocean warming and acidification, and increase in extreme weather events.

We're gonna look at all of these in a little bit more detail now.

Polar ice is melting, especially in the Arctic and the Antarctic.

We have an image here of this Arctic sea ice.

The yellow line shows the average extent of sea ice between 1981 and 2010, and as we can see, global sea ice is shrinking.

This shows its extent in 2024, and this shows that it shrank almost 2 million kilometres squared below that average area.

It's been monitored for the past 46 years, and persistent trends have been seen, where we have more melting in the summer and less ice formation in the winter.

By monitoring these sea ice changes, it's seen a wide ranging impacts on the Arctic ecosystems. We've seen losses and changes in polar wildlife habitat, which is having an impact on species that live there.

For example, the polar bears who rely on the sea ice for hunting.

This image here shows regional means sea level change, and as we can see from the colours on the map, regional mean sea level is rising in the majority of places across the world.

The warming of oceans causes sea water to expand, which contributes to sea level rise through the idea of thermal expansion.

Melting ice sheets and glaciers, particularly in Greenland and Antarctica, release large volumes of water into the oceans, which further raise sea levels.

And the areas that are particularly vulnerable are the coastal areas and the low-lying areas.

For example, Small Island Developing States, coastal megacities, and deltas, as we can see on that map.

Check for you now.

The environmental effects of climate change are affecting the survival of polar bears.

Is that true or false? Pause the video and come back when you're ready.

I hope you said true.

But why? Pause it again and discuss with your partner.

You might have said something like, "Arctic sea ice is declining due to global warming.

Polar bears use the ice for hunting, therefore it is harder for them to feed themselves and they're young." Low-lying areas such as Bangladesh and small island nations, for example Tuvalu, are at risk of being submerged.

We can see here this map of Bangladesh, which shows a significant proportion of it is at very low elevation, so very vulnerable to sea level rise.

Higher sea levels lead to faster erosion of cliffs and beaches and habitats can be destroyed and species lost as wetlands, mangroves, and salt marshes are lost to coastal flooding and erosion, and these ecosystems are unique to this particular location along the coast.

Seawater can also move into rivers and underground water supply, something that we call salt water intrusion.

This has an impact as it makes the water too salty for drinking and it affects ecosystems that rely on fresh water further inland.

Ocean warming caused by the rising global temperatures raises sea temperatures, and this map shows sea surface temperature anomalies in 2023.

The dark red and the orangey colours shows where it is higher than expected.

Ocean acidification driven by increased CO2 absorption from the atmosphere reduces the ocean pH, making them more acidic, so our oceans are becoming warmer and more acidic.

Ocean acidification and warming harms marine ecosystems and it's causing coral bleaching, it's disrupting food chains, and it's altering fish migration, threatening species like shellfish.

This map here shows the northeast coast of Australia where we find the Great Barrier Reef.

This is experiencing coral bleaching as the sea temperatures rise.

This causes the corals to expel algae, which means that they lose colour and essential nutrients, which weakens the reef and endangers marine biodiversity.

Attribution studies assess how climate change affects the intensity, frequency, or impact of extreme weather events.

We look here at this map, we can see the red circles indicates events that were more severe or more likely due to climate change in 2024.

The statistics linked to this show us how severe this was.

74% of extreme weather events in 2024 were more likely or more severe due to climate change, 9% were less likely or less severe.

So overall, 83% of these extreme weather events were influenced by human-caused climate change.

Rising temperatures and more droughts create conditions that cause larger, more frequent wildfires, leading to habitat destruction and biodiversity loss, heat waves can lead to ecosystem stress and water shortages, and heavier rainfall and more intense storms result in flooding, damaging ecosystems and contaminating water sources with pollutants.

In 2019-2020, during the bushfire season in Australia, wildfires across the country were fueled by extreme heat and prolonged drought, and it became known as the Black Summer.

This had a huge impact on the environment, with over 18 million hectares burnt and around 3 billion animals affected, massively reducing the biodiversity.

And emissions, particulate emissions from burning the vegetation reduced the air quality.

Burned areas also suffered increased erosion, which degraded soil and water quality.

Another check for you now, true or false? In 2024, climate change did not affect extreme weather events.

Is that true or false? Pause the video and come back when you're ready.

It's false.

But why? Can you justify your decision? Come back when you're ready.

Hopefully you said something like this, "Overall, 83% of the extreme weather events in 2024 were affected by climate change.

74% were made more likely or more severe, and 9% made less likely or less severe." If so, well done.

First task for you now.

Can you explain how climate change is affecting the environment in two different ways? Use examples in your answer if you can.

And Jacob says, "As this says, 'Explain,' I need to give reasons and develop my ideas.

I might use sea level rise as one of my examples and explain how it affects the environment." Have a go and come back when you've got your answers.

Had you put something like this? "Increased ocean temperatures is affecting marine ecosystems. It causes coral reefs to expel the algae living inside them, leading to coral bleaching.

Reefs, like those in the Great Barrier Reef in Australia, are very sensitive to temperature changes.

And as the oceans warm, coral reefs suffer from mass bleaching events, threatening marine biodiversity." And the second point, "Sea level rise is leading the flooding of low-lying coastlines and small island nations, for example Tuvalu.

This is leading to increased coastal flooding, damage to mangrove forests, and loss of biodiversity as habitats are damaged." If your answers were similar to this, well done.

That's excellent.

Let's move now to our second learning cycle, the impacts of climate change on people.

These are the main things that we're going to look at in this lesson.

Economic impacts of extreme weather, health impacts, displacement of populations, and threats to food security.

Extreme weather event or weather events are becoming more frequent and more intense, causing significant economic and social impacts for people across the world.

If we look here at this graph, we can see the number of loss events between 1980 and 2019.

We can see those that are affected by climate change.

So the meteorological events, hydrological events, and climatological events are increasing in number and they are causing more severe effects across the world for people.

Climate-related disasters cost the global economy over $650 billion annually, and this is rising due to more extreme weather events because it leads to high repair costs and it disrupts economies.

Here's an example for you here.

Hurricane Harvey in the U.

S.

A.

in 2017 was estimated at $125 billion in economic costs, as it damaged homes, infrastructure and businesses, and it led to temporary and permanent job losses due to the damage to the environment and the industries.

Check for you now, which of these are economic and social impacts of climate change? Is it A, loss of habitats and reduced biodiversity, B, increased health risks, or C, the cost of repair to damaged infrastructure and buildings? Pause the video and come back when you have an answer.

Did you say B And C, increased health risks and the cost of repair to damaged infrastructure? If so, well done.

That's correct.

Loss of habitat and reduced biodiversity is an environmental impact.

So climate change could reduce global agricultural productivity, and that will affect food security across the world, but particularly for lower-income countries.

This choropleth map gives us an overview of the world's food insecurity in 2021, and we can see that due to more severe droughts and changing rainfall patterns, Sub-Saharan Africa has reduced crop yields, particularly for crops like maize, which people rely on a daily basis.

This therefore affects their food security and it may well increase poverty within the farming communities as they don't have enough food to eat or to sell to make money for other aspects of their lives.

The World Health Organisation reported approximately 150,000 deaths annually from climate-related health issues, and that includes things like heat waves and diseases like malaria.

During the 2015 heat wave in India, over 2,000 people died from heat stroke, dehydration, and related illnesses, and vulnerable groups, particularly elderly and low-income communities, were affected very badly.

We can see there the temperatures that were experienced in Northern India.

Thinking again to the Black Summer wildfires in Australia in 2019 and 2020, it destroyed over 3,500 homes, displacing thousands of people, and sadly resulted in 33 deaths.

So not only did it have those impacts on the environment, it also had social and economic impacts as well.

It also caused widespread air pollution, which led to serious health issues, particularly respiratory problem.

In 2020, 30 to 40 million people were displaced due to climate events such as sea level rise, floods, and storms. Tuvalu is a Pacific island nation of the northeast coast of Australia.

Its average elevation is just two metres above sea level, making it particularly vulnerable to rising sea levels.

In recent years, 80% of Tuvalu's land has experienced flooding and salt water intrusion, which damages the crops and it threatens food security.

And many Tuvaluans have been forced to migrate.

They've been displaced and they are now resettling in New Zealand.

True or false for you here then.

Climate change does not affect people's health.

Pause the video and come back when you have an answer.

Did you say false? If so, well done.

But why? Can you justify it? Have a chat to the next to you.

Did your conversation say something like this? "Air pollution from increased wildfires can increase respiratory diseases, extreme heat waves can cause heat stroke and dehydration, and reduced food security can affect people's diet and well-being." If so, well done.

Task B for you now.

Can you annotate this world map to show the effects of climate change on people and the environment in specific regions? You might want to use examples that I've given you during this lesson, or you may want to go away and research some of your own, but try to refer to at least three different examples.

Pause the video and come back when you're ready.

Your maps might have looked something like this.

Pointing to Sub-Saharan Africa, we've got increased temperatures and prolonged droughts having an effect on food security in Sub-Saharan Africa.

Melting of ice in the Arctic is affecting species who use it for hunting and breeding, for example, polar bears and seals.

And rising sea levels are displacing people in low-lying coastal areas and small island nations, for example, Tuvalu and Bangladesh.

You might have done some research on your own examples.

If you had something similar to this, that's fantastic.

Well done.

Let's move now to the third learning cycle for today's lesson, future projections for climate change.

So we know that human activities are continuing to add greenhouse gases to the atmosphere, but what will the impact be of this in the future? Scientists use data and computer modelling to make projections about what will happen to global temperatures in the future and the impacts this may have on people and the environment.

Global climate models known as GCMs are computer models that simulate the Earth's climate.

They run on massive supercomputers using enormous amounts of power, and they work by taking the present-day conditions and running them forward in time, allowing projections to be made well into the future.

We have an example here of a GCM showing surface air temperature anomalies.

It's using previous data, current data that we know, and then it's projecting it into the future.

Check for you now.

A GCM is a type of computer model, but what does GCM stand for? General circulation model, global climate model or grand computer model? Pause the video come back when you decided.

Did you say global climate model? If so, well done.

GCMS simulate processes happening in the atmosphere, oceans, and on land, for example, the carbon cycle, which we can see here in this image, exchange of carbon between atmosphere, lands, and oceans.

Over time, the complexity and accuracy of GCMS has increased and the modelling is much more detailed.

Intergovernmental Panel on Climate Change uses climate models to make projections about global warming and climate change across the world.

It checks how well previous projections by GCMS and other models have done against actual changes and then uses the most accurate results for its projections.

And we have this graph here showing actual temperature change together with projections.

What do you notice about this graph though? What do you notice about the projection for global temperature change? Izzy says, "There's more than one projection," which is correct.

Well done, Izzy.

There are good reasons why the IPCC has more than one projection for global climate change.

The main reason is that what happens to global temperatures depends on what happens to greenhouse gas emissions.

Emissions may continue to be very high or they may decrease and get down to being even very low.

The reasons for the uncertainty about global temperature predictions is that it is uncertainty about what will happen to the emissions.

The IPCC's projections are for very high, high, intermediate, low, and very low pathways for greenhouse gas emissions.

Uncertainty about how the earth system will respond.

For example, will cloud cover decrease? What impacts will this have? Uncertainty about technological developments, for example, renewable energy or carbon capture.

And uncertainty about how government societies and industry will will respond.

So it takes into account all of these uncertainties when it makes the different projections.

So the IPCC's projections include an uncertainty range, and that means that all likely uncertainties are taken into account in the projection.

So if emissions remain high or very high, it is likely that temperatures will increase by between three to five degrees Celsius.

True or false for you now.

Uncertainty about what will happen to emissions in the future means we cannot predict how global temperatures may change over the next 100 years.

True or false? Pause the video and make your decision.

Hopefully you said false.

But why? Can you justify your decision to the person next to you? I'm sure you will have said something like this.

"Although we cannot be about what will happen to emissions, the IPCC uses an uncertainty range to predict what will happen for different emission scenarios." Well done if you did.

So climate modelling relies on data and equations that accurately model natural processes.

And the same approach can be also applied to impacts of climate change.

One impact that can be modelled accurately is future sea level rise.

Other impacts such as future changes to regional rainfall patterns are harder to model because they are extremely complex.

For 30 years, satellites have been measuring the surface height of oceans around the world.

So we've got some very accurate data about this.

This graph from NASA shows the changes in average global sea level from the level recorded in 1993.

We see a rise of about 99.

5 millimetres.

The blue shading around that black line shows the uncertainty range about the measurements.

The factors that are causing sea level rise can be modelled accurately because they're well-understood.

Equations accurately model the thermal expansion of seawater, but there are still some areas of uncertainty.

The dynamics involved in ice sheet melting in Antarctica.

And also we must take into account feedback loops that can lead to faster ice melt than predicted.

Example, the melting ice exposes darker surfaces that increases the heat absorption and will accelerate further melting.

Check for you now.

Which of these factors involved in sea level rise can be modelled very accurately? A, what will happen to seawater when it warms by one degree celsius, B, what will happen to ice when it warms above zero degree Celsius, and C, what will happen to future greenhouse gas emissions? Pause the video and make your decision.

Did you say A and B? If so, well done.

Task C for you now.

Can you study this graph and answer the following questions? The graph shows the IPCC's projections for sea level rise to 2300.

RCP stands for Representative Concentration Pathways, and it refers to the different scenarios about what might happen depending on greenhouse gas emissions in the future.

Question number one says, "Why are there three projections rather than just one?" And number two, "Why is there shading around each line?" So think back to what we've discussed looking at other graphs during this learning cycle and come back when you have answers to questions one and two.

Did your answers read something like this? For number, why are there three projections rather than just one? Because the IPCC has made projections for different scenarios, one in which CO2 emissions reach zero by 2100, one where emissions stop growing by 2,100, and one where they stay high.

And high emissions will mean the most global warming, and therefore the highest sea level rises.

And for number two, why is there shading around each line? This is the uncertainty range, which indicates the extent to which the projection could vary because of uncertainties in the modelling.

Well done if you manage to answer those two questions.

Got to the end of the lesson now, so let's have a little look at the summary.

Climate change is causing sea levels to rise, polar ice to melt, more extreme weather, and ocean warming and acidification.

This is causing environmental impacts that include reduced biodiversity, loss of land, increased coastal erosion, and more frequent and intense extreme weather events.

This is affecting people through a range of economic and social impacts.

For example, loss of income, health risks, reduced food security, and displacement.

Projections for climate change in the future are based on computer modelling, which allows for uncertainties.

There's a lot of information covered in today's lesson, so well done.

I hope now that you can speak more confidently about the effects of climate change on both people and the environment.

Well done.

I look forward to seeing you again soon.