Stock and Flow System Models

in Sustainability ScienceToni Menninger - http://de.slideshare.net/amenning/presentations

 

• The Global Food System: Sustainability and Food Security• The Global Carbon Cycle and CO2 Buildup in the Atmosphere• The Climate System and Global Warming

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?

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? 

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? 

The Climate System and Global WarmingExercise: What are the drivers of the climate system? 

In the table, 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 agencyC) Variables indirectly influenced by human agencyD) An increase in the variable causes an increase in global temperatureE) 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          

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? 

The Climate System and Global WarmingExercise: What are the drivers of the climate system? 

In the table, 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 agencyC) Variables indirectly influenced by human agencyD) An increase in the variable causes an increase in global temperatureE) An increase in the variable causes a decrease in global temperature

Variable name A B C D ESolar Output X     X  

Distance from Sun X       X

Albedo X ? X   X

Green house gas (GHG) 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    

Stock and Flow System Modelsin Sustainability Science

© 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