1-1: Overview of Global Change

"Today the scale of our interventions in nature is increasing and the physical effects of our decisions spill across national frontiers. The growth in economic interaction between nations amplifies the wider consequences of national decisions. Economics and ecology bind us in ever tightening networks. Today many regions face risks of irreversible damage to the human environment that threaten the basis for human progress."

Our Common Future
The World Commission on
Environment and Development 1987

Pre-Class Preparation

There is no pre-class preparation for Overview of Global Change. Welcome to the course!!!

Objectives

To understand the importance of global environmental change.
To identify the general areas of our environment that are changing and explore the potential consequences of these changes.

Procedure

Read the learning unit.
Class images
Take the learning unit quiz. Quizzes are available from your portfolio. You may access your portfolio via the list of students participating in this years course, as represented by the icon below.

Additional Required Reading. Although you are not ultimately responsible for content listed in this section, we encourage you to fully explore the links in order to provide a better scope on the upcoming class discussion.

	An Introduction to the Science of Man-made Climate Change. (From UNEP.)
	Subcategories of Global Change.
	The United States Global Change Research Program (USGCRP). Note: This page is still under construction...
	1993 Report on the U.S. Global Change Research Program

Class Discussion

Problem to ponder...
What distinguishes a "global change" environmental issue from other environmental issues? We will be discussing this question, plus other questions raised by students during class.
Class Discussion Summary: by classmate Matthew Emht

This class followed the notes pretty closely. First the potential of a species (relative to carbon dioxide) was discussed. This was defined as a ratio of integrals of the concentration and forcing ability of respective species. Also noted was the fact that atmospheric lifetimes is a third important factor. The concentration of a species is related to the past emissions minus the amount decayed to more benign species.
Next the cumulative effect of each species was considered. CO₂ scored highest at 61%. Methane was next (low concentration, short life, but high forcing ability) at 15%. NO_x, N₂O, and all CFCs came in last at about 5-6%. CFCs are interesting because of their super low conc. combined with very high forcing and lifetimes.
Finally four economic scenarios were presented. Scenario A showed no decrease in pollution rates. Scenario B presented modest reductions eventually reaching a pollution rate constant around 2050. Last scenarios C and D showed drastic switches to renewables and nuclear by 2100 and 2050 respectively.
After looking through the atmospheric effects of all four it was concluded that moderate reductions (Scenario B) would give the most improvement for the transition work required. Therefore they would serve the best giving our current conditions.

Post-Class Materials

Participate in the electronic dialog. Use this forum for:

continuing class discussion;
posing new questions to students or the instructor;
responding to issues/questions raised by students in class/electronic dialog.

Visitor Access (Visitors are welcome to participate in the dialog. Just click on the icon below)	Student Access (Students must post all dialog from their portfolio. Click on the icon below to access the student list.)

Recommended Reading Materials

	UNEP Climate Change Fact Sheets
	Bloom, David E., 1995: International Public Opinion on The Environment. Science 269, 354-358.
	Houghton, J. T., L. G. Meira Filho, B. A. Callander, N. Harris, A. Kattenberg, and K. Maskell, 1996: Climate Change 1995. The Science of Climate Change. Cambridge University Press, 55-57.

References

	Global Change Course Earthreview - Links on the current state of the planet.
	Global Change Glossary (J through L)
	Global Climate Change Acronyms and Glossaries
	Global Warming and Climate Change Brochure. From the U.S. Global Change Research Information Office.
	Glossary of Climate Change Terms.
	The Intergovernmental Panel on Climate Change Homepage (through EPA).
	Bruce, J., H. Lee, and E. Haites, 1996: Climate Change 1995: Economic and Social Dimensions of Climate Change, (IPCC Working Group I Report) Cambridge University Press.
	Houghton, J. T. et al., eds., 1996: Climate Change 1995: The Science of Climate Change, (IPCC Working Group I Report). Cambridge University Press .
	Lubchenco, Jane, 1998: Entering the century of the environment: A new social contract for science. Science 279, 491-497.
	Watson, R.T., M. C. Zinyowera, and R. H. Moss, 1996: Climate Change 1995: Impacts, Adaptations and Mitigation of Climate Change, (IPCC Working Group I Report). Cambridge University Press.