002 - Global Energy Balance

Geographic Knowledge and Understanding

Changes in the global energy balance, and the role of feedback loops, resulting in:

Solar radiation variations, including global dimming due to volcanic eruptions

Terrestrial albedo changes and feedback loops

Methane gas release and feedback loops

Key Concepts

The process of change to the global energy balance is created by variations in solar radiation, terrestrial albedo and releases in methane gas. The changes can create the possibility of positive and negative feedback looks.

Aims

  • To have knowledge of what a positive and negative feedback loop are.
  • To understand how solar radiation and volcanic eruptions can change the global energy balance.
  • To have knowledge of how the terrestrial albedo fluctuates and how this creates change to the feedback loops.
  • To understand how methane gas is released into the atmosphere and how this impacts the global energy balance.

Key Terminology

            • Positive feedback loops
            • Negative feedback loops
            • Permafrost

Define the words above by using the 'Useful Links' below.


Useful Links

Activity One - Watch

In the previous lesson we discussed what a climate budget may be and the factors that may impact it. We now need to focus on how these factors can impact feedback loops. Remember that a feedback loop can either accelerate or decelerate the warming of the planet. Positive feedback loops cause global warming but negative feedback loops brings the cycle back to a equilibrium by cooling the planet. Watch the youtube clip below and write down all the different factors that can cause either a positive or a negative feedback loop.

Activity Two - Draw and Annotate

You now know what a feedback loop is and have created a systems diagram in the previous lesson. You are now going to watch a series of youtube clips and create a feedback look systems diagram to show how solar radiation variations can cause both positive and negative feedback loops. You may want to initially make notes from the youtube clip using www.videonot.es and then create the diagram on A4 paper. Remember you need to annotate the digram to show you understand the process. Make sure you include the following reasons for the variations in solar radiation.


                    • Volcanic emissions and global dimming
                    • Changes in solar output
                    • Changes in Earth's orbit (Milankovitch's theory)
                    • Cosmic collisions


One of the skills required of a geographer is the ability to draw and you could be potentially asked to draw a systems diagram in the exam.

Useful Resource

'Geography Global Change. Study and Revision Guide' by Simon Oakes Page 39

Activity Three - Draw and Annotate

You now know what a feedback loop is and have created a systems diagram in the previous lesson. You are now going to watch a series of youtube clips and create a feedback look systems diagram to show how terrestrial albedo variations impact global temperatures. You may want to initially make notes from the youtube clip using www.videonot.es and then create the diagram on A4 paper. Remember you need to annotate the digram to show you understand the process.

Useful Resource

'Geography Global Change. Study and Revision Guide' by Simon Oakes Page 39 and 40

The Conversation - How Antarctic Ice melt can be a tipping point

Activity Four - Draw and Annotate

You now know what a feedback loop is and have created a systems diagram in the previous lesson. You are now going to watch a series of youtube clips and create a feedback look systems diagram to show how methane gas impact global temperatures. You may want to initially make notes from the youtube clip using www.videonot.es and then create the diagram on A4 paper. Remember you need to annotate the digram to show you understand the process.

Useful Resource

'Geography Global Change. Study and Revision Guide' by Simon Oakes Page 41

Exam Style Question

Using an annotated diagram, explain how variations in solar radiation can cause a negative feedback loop. [4 marks]