Part 1. Causes of Global Climate Change

Conceptual Understanding:

Key Question:

How do natural and human processes affect the global energy balance?

Key Content:

1. The atmospheric system, including the natural greenhouse effect and energy balance (incoming shortwave radiation and outgoing longwave radiation)
2. Changes in the global energy balance, and the role of feedback loops, resulting from:
   • terrestrial albedo changes and feedback loops
   • solar radiation variations, including global dimming due to volcanic eruptions
   • methane gas release and feedback loops
3. The enhanced greenhouse effect and international variations in greenhouse gas sources and emissions, in relation to economic development, globalization and trade

Synthesis, evaluation and skills opportunities

The complexity of the dynamic climate system and the spatial interactions of different processes and feedback mechanisms

Tuesday 29 October 2024

The Atmospheric System

Objective: To be able to describe the functioning of the atmospheric system in terms of the energy balance between solar and long wave radiation.

Lesson 1. The Atmospheric System (Google Doc)

Starter: Watch the video below about the Earth’s Atmosphere.

After watching the video, label the diagram in the Google Doc with the names of the five layers of the atmosphere!

Task 1. Watch the YouTube video below.

Now complete the wordfill exercise on the Google Doc using the words from the word bank.

​Task 2. Key Terms and Definitions

Match the key terms with the correct definition in the table on the Google Doc.

The Atmospheric Energy Budget 

The earth and its atmosphere constantly receives solar radiation but there are long and short term variations in the earth’s climate & recent decades have seen the general rise in global temperatures. This is global warming and will be covered a little later on in the unit. 

Task 3. Make a copy of the Atmospheric Energy Budget Diagram below. Then watch the video: How Does the Climate System Work? Use the information to make annotated (around the diagram) notes on how the energy budget works and transfers at each stage.

Task 4. Using the video above, answer the questions on your worksheet.

Task 5.  Click here to be taken to Cool Geography. Read the information carefully on the page before completing the four activities in full, at the bottom of the page. Make copies of the maps and diagrams where necessary.

Thursday 31 October and Friday 01 November 2024

Starter: Quick Quiz: 5, 4, 3, 2, 1.

5 – Layers of the atmosphere.

4 – Reasons for energy surplus and deficit.

3 – Greenhouse gases.

2 – Types of radiation.

1 – Definition of insolation.

Natural Causes of Climate Change

When explaining climate change it is important to make the distinction between the more recent industrial age, which only covers the last 200 years or so and the period preceding the industrial age. Temperature changes before the industrial age can only be explained by natural factors. There are many causes, but the ones that we are going to investigate are:

1. Changes in Insolation (Milankovitch Cycles)
2. Albedo Changes and Feedback Loops
3. Sun Spot Activity
4. Volcanic Eruptions

Cause #1. Changes in Insolation (Milankovitch Cycles)

Cause #1. Changes in Insolation (Google Doc)

Serbian scientist Milutin Milankovitch hypothesized the long-term, collective effects of changes in Earth’s position relative to the Sun are a strong driver of Earth’s long-term climate, and are responsible for triggering the beginning and end of glaciation periods (Ice Ages).

Specifically, he examined how variations in three types of Earth orbital movements affect how much solar radiation (known as insolation) reaches the top of Earth’s atmosphere as well as where the insolation reaches. These cyclical orbital movements, which became known as the Milankovitch cycles, cause variations of up to 25 percent in the amount of incoming insolation at Earth’s mid-latitudes (the areas of our planet located between about 30 and 60 degrees north and south of the equator).

The Milankovitch cycles include:

1. The shape of Earth’s orbit, known as eccentricity;
2. The angle Earth’s axis is tilted with respect to Earth’s orbital plane, known as obliquity; and
3. The direction Earth’s axis of rotation is pointed, known as precession.

Task 1. Open the Google Doc linked above and follow the instructions to complete the tasks set out.

• Milankovitch Background Info
• Milankovitch Cycles Applet

Cause #2 Terrestrial Albedo Changes and Feedback Loops

Cause #2. Albedo Changes and Feedback Loops (Google Doc)

Task 1. Use the information and the videos linked below to complete the worksheet linked above.

Albedo

Albedo refers to the fraction of Sun’s radiation reflected from a surface. The term has its origins from the Latin word albus, meaning “white”. 

It is quantified as the proportion, or percentage of solar radiation of all wavelengths reflected by a body or surface to the amount incident upon it. An ideal white body has an albedo of 100% and an ideal black body, 0%.

The image below shows the albedo values for various surfaces.

Feedback Loops

What are Feedback Loops?

Negative and positive feedback systems keep a system in dynamic equilibrium. A negative feedback decreases the amount of change by reducing some of the inputs, returning the system to stability. Positive feedback is less common. It increases the amount of change. This leads to an imbalance. 

Negative Feedback Example: 

A good supply of grass for rabbits to eat will attract more rabbits to the area, which puts pressure on the grass, so it dies back, so the decreased food supply leads to a decrease in population because of death or out migration, which takes away the pressure on the grass, which leads to more growth and a good supply of food which leads to a more rabbits attracted to the area which puts pressure on the grass and so on and on…. 

Positive Feedback Example: 

Polar ice reflects light from the sun. As this ice begins to melt, less sunlight gets reflected into space. It is instead absorbed into the oceans and land, raising the overall temperature, and fueling further melting. This results in a positive feedback loop called ice albedo feedback, which causes the loss of the sea ice to be self-compounding. The more it disappears, the more likely it is to continue to disappear.

Feedback Video – Introduction

Feedback Video – Example #1 Forests

Feedback Video – Example #2 Permafrost

Feedback Video – Example #3 Atmosphere

Feedback Video – Example #4 Albedo

Cause #3 Solar Radiation Variation from Sunspots

Cuase #3. Solar Radiation Variation from Sunspots (Google Doc)

Task 1. Conduct some research into sun spots, starting with the videos below, and explain how they are linked to the amount of short wave energy that the earth receives.

Task 2. Using the graph below, answer the questions on the Google Doc.

1. Describe the pattern of sunspot activity between 1960 and 2010. 
2. Is there a relationship between sunspot activity and global temperatures? (don’t forget to look for anomalies)

Task 3. Click on this link from the BBC and print out and read the article carefully. 

1. What is the Maunder Minimum?
2. What is blocking?​
3. Outline the impacts of sunspots on continental Europe and its populations. 

Cause #4 Volcanic Eruptions

​Focus: Mount Pinatubo.

Eruption: 1991 in the Philippines. 

Task 1. Familiarise yourself with this specific eruption by clicking on this link. Create a 5 W’s graphic organiser for the eruption (who, what, where, why, when).

Task 2. Using the information within this Live Science Link, particularly focusing on the section entitled ‘Pinatubo’s global reach’, the section above on Global Dimming and the graph below, explain how volcanic eruptions can influence climate.

Tuesday 05 November 2024

Starter: Complete this online crossword.

The Enhanced Greenhouse Effect

The enhanced greenhouse effect, is the impact on the climate from the additional heat retained due to the increased amounts of carbon dioxide and other greenhouse gases that humans have released into the earths atmosphere since the industrial revolution.

The increase in world’s greenhouse gases is linked to industrialisation, trade and globalisation. As industrialisation has increased so too has the increase of atmospheric CO2.

Common Misconception!

Do not confuse the enhanced greenhouse effect with the greenhouse effect! The greenhouse effect is vital for life on Earth!

Global variations in greenhouse emissions

The source of greenhouse gases varies by both country and the type of activity. In general, countries that have a higher level of economic development tend to have higher energy use, which in most countries means they burn more fossil fuels. The graphic below shows the 2009 data for emissions by country. It’s clear that the more economically developed countries of Europe, North America and Asia have higher levels of emissions than the relatively less economically developed areas of South America and Africa.

Source: https://www.visualcapitalist.com/mapped-air-pollution-levels-around-the-world-2022/

Global variations in greenhouse gas sources

However, there is not a simple relationship between economy and emissions.

• In High Income Countries (HICs), energy requirements are high because of domestic consumption as well as industry. However, HICs often have strict environmental laws and are switching to relatively expensive new technologies to produce renewable energy with no or few emissions. This is demonstrated by the graphic below, showing that richer countries can reduce emissions while enhancing their economy (Aden, 2016).
• In Middle Income Countries (MICs) that have emerging manufacturing industries, industrial energy use is very high, while domestic consumption is lower. Many MICs that are industrialising burn large amounts of fossil fuel because the technology is inexpensive and widely available. Even so, some MICs such as China are strongly promoting renewable energy sources.
• In Low Income Countries (LICs), emissions are generally low as there are few industries and also a smaller demand for domestic consumption. When the per capita income is low, there is less money for products that use energy such as air conditioners.

Source: Aden, 2016

The graphic below shows the world’s top ten greenhouse gas emitters in 2012. This data is still pretty much the same in 2024. The interactive version on the original website allows you to check exact figures and is well worth a look. The overall spread of the top ten, which contains a mixture of HICs (USA and the countries of the European Union) and MICs, reinforces this complex picture.

Source: Friedrich, 2015.

The growth in these gas emissions over time shows that although the amount from HICs is roughly stable, it is the industrialising regions of the world – especially Asia, led by China and India – that are now producing the most emissions. The two graphs below show the cumulative share of emission and economy and demonstrate the link between the two.

The benefit of looking at total emissions by country is that it shows where the political power lies in terms of making big changes. By looking at the graphs above, it is clear that China, USA and OECD European countries make up the biggest share of the emissions. If those countries change their emissions levels it will have a big impact on total emissions.

Global variation in per capita emissions

However, looking at the levels of emissions by country and region can be misleading. For example, it’s natural that China has high levels of emissions because the population of China is so large. By switching to look at ‘per capita’ emissions, it is clearer to see which countries have the most unsustainable levels of emissions. The image below shows the ‘carbon footprint’ in graphic form; the left foot is for total emissions and the right foot shows per capita emissions. It is very clear that small states – especially island nations – have people with the individual lifestyles that lead to high emissions.

Source: Standford Kay Studio, 2007.

The impact of globalization and world trade

This complex picture of the sources of emissions and the countries responsible for them can be explained by the impact of economic development, globalization and world trade.

Countries that are more economically developed have high levels of resource consumption, including energy. As countries become more economically developed, their emissions will therefore increase. The increasing interconnectedness of the world – ‘globalization’ – has helped many economies to increase. One aspect of this is world trade: countries that trade more tend to be countries with high emissions either because they have a lot of manufacturing industries, or because they have a high consumption of resources.

This can include ‘hidden’ or ‘embedded’ emissions. Hidden emissions are those emissions that are physically released in one country at the point of manufacturing a product. For example, Apple makes its iPhones in China, where greenhouse gases are released. But the product is then sold to another country, which is therefore ‘responsible’ for the emissions. This is because the product would not be produced if it weren’t for the demand from the destination country. This is why some people consider the higher income countries to have even more responsibility than the figures shown on this page.

Learning Activities

• Describe the global distribution of greenhouse gas emissions. [3] Tip: This question is asking about the spread of emissions across the world.
• Outline the link between economic development and greenhouse gas emissions. [3]
• Describe the changes in emissions by region between 1990 and 2012 according to the graph below. [4] Tip: This question is asking about the changes in emissions in different regions over time, so you should mention things such as ‘increasing’ ‘decreasing’ ‘sharp rise’ etc.

• Suggest reasons why China is increasing its levels of greenhouse gas emissions. [4]
• Using named examples of countries, distinguish between the meaning of ‘total’ emissions and ‘per capita’ emissions. [4]
• Suggest how and why including embedded (hidden) emissions might affect the emissions totals for:
  1. China [2]
  2. The United States [2]

Assessment 2.1 | Carbon Sources New Report

Due: Tuesday 12 November 2024

Task: Write a script, and then create a video, for a 3-5 minute news report on the global variation in greenhouse gas emissions.

Success Criteria:

1. Include at least two graphics from this page as the visuals that will appear on screen.
2. Explain what the graphics show.
3. Try to include reference to the 4P’s – Power, Place, Possibility and Processes.
   • Place – Which countries emit the largest/smallest quantities of C02? Can they be categorised by level of economic development? Are there differences between overall emissions and those per capita? 
   • Processes – How are these emissions created? Do the emissions just affect the emitting countries or are there processes in place that disperse the problem?  What’s the link to the Enhanced Greenhouse Effect? Think about globalisation & trade.
   • Possibility – What could future patterns in emissions and targets be? (Think about SDG’s) How can we reduce emissions and reduce impacts on MIC’s & LIC’s?
   • Power – Who are those that aim to change these patterns? (Think about SDG’s, Climate Change Deals etc) as well as those governments who are promoting economic growth through industrialisation and processes of globalisation. 

IB DP Geography Script Assessment Rubric

Criteria	Level 1-2 (0-5 points)	Level 3-4 (6-10 points)	Level 5-6 (11-15 points)	Level 7 (16-20 points)
Knowledge and Understanding	Limited understanding of greenhouse gas emissions; minimal mention of the 4 P’s.	Some understanding; basic reference to the 4 P’s but lacking depth.	Clear understanding; detailed account of the 4 P’s are discussed with some examples.	Thorough understanding; insightful analysis of the 4 P’s, supported by relevant examples.
Application of Knowledge	Little to no application of relevant data; graphs are either missing or not explained.	Some application of data; graphs included but explanations are superficial.	Good application of data; graphs effectively integrated and explained.	Excellent application; graphs are well-chosen, clearly explained, and enhance the argument.
Organization and Clarity	Poorly organized; ideas are unclear or disjointed; difficult to follow.	Some organization; ideas are present but lack clear transitions; moderate clarity.	Well-organized; clear flow of ideas with effective transitions; generally easy to follow.	Exceptionally well-organized; logical flow with strong transitions; ideas presented clearly and compellingly.
Language and Communication	Limited use of appropriate geographical terminology; many errors in grammar and vocabulary hinder understanding.	Basic use of terminology; some errors in grammar and vocabulary, but meaning is generally clear.	Good use of relevant terminology; few grammatical or vocabulary errors; meaning is clear.	Excellent use of terminology; sophisticated vocabulary and grammar; highly engaging and clear communication.