Past, Present, and Probable Future of

Atmospheric Carbon Dioxide

Dr. Robert MacKay

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

Acknowledgement

• Aslam Khalil, PSU Physics

• Clark College

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

Today’s Atmosphere

John Tyndall ~1867

“The aqueous vapour constitutes a local dam,

by which the temperature at the earth's surface

is deepened; the dam, however, finally

overflows, and we give to space all that we

receive from the sun.”

John Tyndall ~1867“Aqueous vapour is a blanket more necessary to

the vegetable life of England than clothing is to

man. Remove for a single summer-night the

aqueous vapour from the air which overspreads

this country, and you would assuredly destroy

every plant capable of being destroyed by a

freezing temperature. The warmth of our fields

and gardens would pour itself unrequited into

space, and the sun would rise upon an island

held fast in the iron grip of frost.”

Greenhouse Gases

•Water Vapor

•Carbon Dioxide

•Ozone

•Methane

•Nitrous Oxide

•Chlorofluorocarbons

Cooling to offset warming

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

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

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

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