Past, Present, and Probable Future of

Atmospheric Carbon Dioxide

Dr. Robert MacKay

Outline•Introduction/ Motivation•Natural and Anthropogenic sources of change•Recent temperature record•Past CO2•Present CO2•A simple mathematical/conceptual model•Future projections•Future emissions•Discussion

Natural and Anthropogenic Climate Forcing

No Atmosphere http://cs.clark.edu/~mac/meteor/Animations/greenhouse.jnlp

Today’s Atmosphere

Greenhouse Gases•Water Vapor•Carbon Dioxide•Ozone•Methane•Nitrous Oxide•Chlorofluorocarbons

Cooling to offset warming

http://data.giss.nasa.gov/gistemp/graphs/

pH change between 1751 and 1990s. Estimate are that globally ocean surface water pH levels have decreased by as much as .12 units for atmospheric CO2 change from 280 to 360 ppm.

http://www.terrain.org/articles/21/burns.htm

Carbon Dioxide in Prehistoric times

Vostok Ice Core data

http://cs.clark.edu/~mac/physlets/GlobalPollution/CO2assign.htm

http://cs.clark.edu/~mac/physlets/GlobalPollution/carbon_dioxide.htm

http://cs.clark.edu/~mac/physlets/GlobalPollution/carbon_dioxide.htm

Because of long time delays for the carbon cycle, drastically different scenarios yield very similar results for a 20 year time horizon, but drastically different result for a 50 to 100 year time horizon.

http://www.newscientist.com/article/dn10507-carbon-emissions-rising-faster-than-ever.html

http://cdiac.ornl.gov/trends/emis/em_cont.htm

US Carbon emissions through 2004

http://cdiac.ornl.gov/trends/emis/em_cont.htm

China’s carbon emission through 2004

http://cdiac.ornl.gov/trends/emis/em_cont.htm

Russia’s carbon emission through 2004

http://cdiac.ornl.gov/trends/emis/em_cont.htm

India’s carbon emission through 2004

Fossil Fuel Reserves

~40 yrs Oil~80 yrs Natural gas

~200 years coal

World Population

http://www.physicstoday.org/vol-57/iss-7/p47.html

Fossil Fuel ReservesOil

http://www.physicstoday.org/vol-57/iss-7/p47.html

http://www.eia.doe.gov/pub/oil_gas/petroleum/feature_articles/2004/worldoilsupply/oilsupply04.html

Fossil Fuel ReservesNatural Gas

http://www.physicstoday.org/vol-57/iss-7/p47.html

Fossil Fuel Reservescoal

http://www.physicstoday.org/vol-57/iss-7/p47.html

http://chooseclimate.org/jcm/index.html

http://chooseclimate.org/jcm/index.html

A -developing countries B-Industrialize countries

http://cs.clark.edu/~mac/CarbonCycle.ppt