Toni Menninger - http://de.slideshare.net/amenning/presentations

Stock and Flow System Models in Sustainability Science Toni Menninger - http://de.slideshare.net/amenning/presentations

For an introduction to stock and flow diagrams, see the book Thinking in Systems by

Donella Meadows, or https://www.systemdynamics.org/DL-IntroSysDyn/stock.htm.

The Global Food System: Sustainability and Food Security

Which variables are related to the sustainability of the food system?

The model is far from complete. Can you identify additional variables?

Where would you intervene to increase food security?

Toni Menninger - http://de.slideshare.net/amenning/presentations

The Global Carbon Cycle and CO2 Buildup in the Atmosphere

How do humans modify the carbon cycle?

How can we reduce the CO2 buildup in the atmosphere?

Toni Menninger - http://de.slideshare.net/amenning/presentations

The Climate System and Global Warming

Exercise: What are the drivers of the climate system?

Identify positive (reinforcing) and negative (balancing) feedback loops. Can you identify leverage points?

In the table below, identify the following variables and mark them in columns A to E:

A) Variables that are drivers of the climate system (directly influence surface heat/temperature)

B) Variables directly influenced by human agency

C) Variables indirectly influenced by human agency

D) An increase in the variable causes an increase in global temperature

E) An increase in the variable causes a decrease in global temperature

Variable name A B C D E

Solar Output

Distance from Sun

Albedo

Green house gas (GHG) concentration in the atmosphere

Extent of ice cover

Ocean acidity

Sea Level

Fossil fuel combustion

Deforestation

Emissions from Agriculture

Global Mean Temperature

Toni Menninger - http://de.slideshare.net/amenning/presentations

© by Toni Menninger MSc.

Use of the present materials for educational purposes permitted.

Questions or comments please email toni.menninger@gmail.com.

Related lectures and problem sets available at

http://www.slideshare.net/amenning/presentations/:

• The Human Population Challenge

• Energy Sustainability

• World Hunger and Food Security

• Economics and Ecology

• Exponential Growth, Doubling Time, and the Rule of 70

• Case Studies and Practice Problems for Sustainability Education:

• Agricultural Productivity, Food Security, and Biofuels • Growth and Sustainability

Answers to exercise:

Variable name A B C D E

Solar Output X X

Distance from Sun X X

Albedo X X? X X

GHG (green house gas) concentration in the atmosphere X X X

Extent of ice cover X X

Ocean acidity X

Sea Level X

Fossil fuel combustion X X

Deforestation X X

Emissions from Agriculture X X

Global Mean Temperature X