Mass Balance for the carbon cycle

Robert MacKay

Clark College and Washington State University Vancouver, WA

Camping

Student Learning Goals

Use a model to estimate the future concentrations of carbon dioxide under several different assumed emission scenarios.

Learn how different carbon dioxide emission scenarios influence our best prediction of future global temperatures.

Learn how a mass balance model applies to the global atmosphere. Calibrate a model with recent observations. Understand the sluggishness of the carbon cycle to anthropogenic

changes. Synthesize results into a well written summary. Accurately read graphical information. Read and interpolate data from a table of values.

http://serc.carleton.edu/quantskills/activities/co2_global.html

http://serc.carleton.edu/introgeo/teachingwdata/examples/CFCsModel.html

http://serc.carleton.edu/introgeo/mathstatmodels/examples/MassBalance.html

From page 212 IPCC “Climate Change 2007 The Physical Science Basis”

IPCC 2007 Figure 7.3

The Global Carbon Cycle for the 1990s . Red anthropogenic black preindustrial.

From the diagram above, estimate the fraction of total anthropogenic carbon emissions that are attributable to land use changes.

IPCC 2007 Figure 7.3

The Global Carbon Cycle for the 1990s . Red anthropogenic black preindustrial.

From the diagram above, estimate the fraction of total anthropogenic carbon emissions that are attributable to land use changes.1.6/(8.0)=0.20 =20%

IPCC 2007 Figure 7.3

The Global Carbon Cycle for the 1990s . Red anthropogenic black preindustrial.

From the diagram above, estimate the fraction of all carbon emitted from human activity that is still in the atmosphere.

IPCC 2007 Figure 7.3

The Global Carbon Cycle for the 1990s . Red anthropogenic black preindustrial.

From the diagram above, estimate the fraction of all carbon emitted from human activity that is still in the atmosphere.

165/(244+39)=58%

IPCC 2007 Figure 7.3

Basic Model

What’s missing from this carbon cycle model?

Basic Model

What’s missing from this carbon cycle model?

Rock (Lithosphere)

and Humans

[ ] ( ) ( ) ( ) ( )ttttttttt SaeASaeASaeASaACO *** 33/1

,322/1

,211/1

,10,012 +++++++= −−−+

τττ

a0=0.217a1=0.259a2=0.338a3=0.186

τ0= infiniteτ1=172.9τ2=18.51τ3=1.186

IPCC 2007 page 213

Introduction to multi-box models (lecture notes)http://www.atmosedu.com/WSU/esrp310-550/notes/BoxModels/MatrixPractice1.pdf

“Normal modes and the transient response of the climate system” , GRLMacKay and Ko, 1997 (http://www.atmosedu.com/WSU/esrp310-550/OceanModel.pdf )

Model and preliminary assignment

http://www.atmosedu.com/physlets/GlobalPollution/carbon_dioxideCLEAN.htm

Conclusion The model can be used in an interactive lecture

discussion or as an assignment. Implements the 2007 IPCC carbon impulse response

function. Captures both the fast response and the sluggishness of

the carbon cycle. Helps students understand how policy changes today

have limited short term (20 yr) influence but important long term (60 yr) influence.

Gives students more practice using graphical information.

Open ended questions allow student to think for themselves.