Dr. Charles Ess - Philosophy and Religion Department - Drury University
Web Resources on Global Warming, a very comprehensive collection of web sites, including links to NASA, NOAA, etc. (probably the best place to start)
The United Nations maintains its Climate Change Bulletin on-line, as part of a web site on The United Nations Framework Convention on Climate Change
The web site includes four important documents:
Synthesis of Scientific-Technical Information Relevant to Interpreting Article 2 of the Convention [saved under "UN Summary on climate change"]Working Group I Summary for Policymakers: The Science of Climate Change, IPCC Working Group I (1995) [saved under "UN science summary"]
Working Group II Summary for Policymakers (Scientific-Technical Analyses of Impacts,
Adaptations, and Mitigation) [saved under "UN mitigation summary"]
Working Group III Summary for Policymakers (The Economic and Social Dimensions of
Climate Change) [saved as"UN WG III summary"]
A "student conference on global warming web pointers" has some good leads, including a link to the Global Climate Perspectives System (a joint project of two NOAA labs), which provides data sets, software for generating visualizations, and the GFDL Global Climate Models
"Global Change: Electronic Edition" includes comprehensive bibliographic listings
The Hadley Centre for Climate Prediction and Research (U.K), listing of historical temperature records
The U.S. Geological Survey Global Change Research Program (description of projects, some project papers and abstracts)
An upper-level student project on global warming, with some good cartoons, models, and links
points out the limits to the Global Climate Models, including:
ResolutionOne of the biggest problems with GCM's is the processor speed of the
computer. As technology improves, the resolution of the simulation will
improve. Models cannot simulate processes that occur on smaller scales than
each box. Methods have been developed to correct for this, but these methods
involve many assumptions. For example, clouds are processes which are too
small for the model's resolution. To accomodate for this, the overall effect
of clouds is modeled, or the overall moisture content of the box is
correlated to the cloud cover.
Clouds
Also, the feedback of clouds is unknown. It is not certain whether or not
the net effect of clouds is a heating or cooling of the Earth. For example,
clouds reflect the short wave radiation from the sun which can keep the
earth cool, but reflected radiation can be absorbed by clouds which can warm
the earth. One fundamental problem is in the difficulty of modeling water in
its three phases (solid, liquid, vapor). Further study of clouds should
improve models.
Momentum Sources and Sinks
Present approaches to the modeling of momentum sinks in the atmosphere are
very crude considering how momentum effects general circulation. More study
needs to be done.
Interactions with the rest of the climate
Interactions of the atmosphere and the other components of the climate
system are not all fully understood or modeled. Improvements are needed for
land surface processes, hydrology, biology, snow cover, sea ice, and
ocean-atmosphere interaction.
A summary of the models' results:
In 1896, the Swedish chemist Svante Arrhenius, realized the CO2 wasincreasing in the atmosphere, made some calculations, and concluded that if
GHG's tripled, the global average temperature would increase 8 to 9 degrees
Celcius.
This is a very reasonable estimate, and is near some of the estimates of
GCM's. Most models attempt to predict the effects of doubling CO2. The GCM's
usually double the CO2 in two ways:
* Equilibrium - CO2 is doubled instantly, and the system comes to
equilibrium
* Transient - CO2 is slowly and realistically increased until it is
doubled
The equilibrium model results show that the average global temperature will
increase 2-5 degrees Celcius. This results from a combination of factors,
such as feedback of water vapor, clouds, and snow and ice albedo changes.
The equilibrium model seems to be less accurate than the transient model
because many feedback mechanisms are ignored.
The transient model results show that the average global temperature will
increase 1-2 degrees Celcius. This results from the slow release of CO2,
other feedbacks, and incorporating a full dynamic ocean. Warming is greatest
in mid and high-latitudes. Although the models show the stratosphere cools,
the earth's surface temperature increases.
References:
1. Global Warming: "Throwing Cold Water on a Hot Debate." Electrical World.
v. 205, 3. p 9-11. 3/91
2. Brummond, David J., et al. "Symposium on financing catastrophe losses in
the property and casualty insurance industry." Journal of Insurance
Regulation. v12, 4. p. 446-514. 1994
3. Frankhauser, Samuel. "The Social Costs of Greenhouse Gas Emissions: An
Expected Value Approach." Energy Journal. v. 15, 2. p. 157–184. 1994
4. Mathews, Jessica T. Preserving the Global Environment . Am. Assembly.
1991
5. Mendelsohn, Robert., Nordhaus, William D. Shaw, Daigee. "The Impact of
Global Warming on Agriculture: A Ricardian Analysis." American Economic
Review. v. 84, 4. p. 753–7. 9/94
6. Trenberth, Kevin E., Climate System Modeling . Cambridge U. 1992.
7. Wade, Joanne., Holman, Claire., Fergusson, Malcolm. "Passenger Car Global
Warming Potential." Energy Policy. v. 22, 6. p. 509–522. 6/94
8. Source of information Tellus Institute Home Page -- G2S2: The Greenhouse
Gas Scenario System
see also their document, GHG Emissions Modeling