Human Impact on the Biophysical Environment: What Science has learned (Geog 109)
Human activities have changed and will continue to change the face of the earth. This course examines the history, manifestation, mechanisms, and consequences of the interactions between humans and the environment in five aspects: vegetation, soil, biodiversity, water and landforms. Specifically, this course explores three thematic topics: deforestation, desertification, and greenhouse gas increase. The new discoveries from general circulation models and remote sensing will be presented. This is an interdisciplinary course that introduces fundamental knowledge needed for students to understand the general prospect of human and environmental interactions. Students will be trained to develop a specific research interest through interactive discussions.
A brief introduction to the physical elements of the environment establishes their relationships to the discussion topics. In addition we will differentiate the problems that are natural and problems that arise from human impact on the environment. The history of human/environmental interaction, the evolution of the human perspective on environmental issues, and the progress achieved in tackling these issues in the past forty years will also be discussed.
Four basic environmental subjects are presented after the introduction. The section on "biodiversity loss" discusses the main human causes of the biodiversity loss, with the focus on habitant loss and modification, pollution, and overexploitation. This section also discusses the conservation measures taken to solve this problem. The section on "the human impact on soil" covers soil salinity, soil erosion and compaction. Issues explored include physical and chemical causes of the soil erosion and salinity and the local and remote consequences. The remedies that have been developed to cure soil degradation will also be introduced. The section on "water" explores the water resources in the world and the alternation due to human activities, which includes the inland waterway, reservoirs, ground water depletion and water pollution. Indirect alternations, such as vegetation transformation of water are to be discussed in desertification and deforestation. The section on "geomorphology" covers the issue of landform changed caused by excavation, construction, sedimentation, ground subsidence, and seismicity.
After we finish covering the four environmental subjects, we begin exploring the three thematic topics. In this part, the latest scientific development, including the results using computer models and remote sensing, will be presented and discussed. Vegetation change is probably one of the most important issues. Humans have had a greater influence on plant life than on any of the other components of the environment. Deforestation and desertification will be discussed in depth. The section on "deforestation" examines the fundamental causes of deforestation, and its impact on secondary forest, soil degradation, CO2 flux, fauna, and water problems. The section on "desertification" discusses land cover change in marginal dry land. The controversy in the definition and understanding of desertification and the causes of desertification, such as overgrazing, are presented. A case study, Sahel desertification on the decadal regional climate and environmental change, will be studied in detail. In these two sections, the simulated results from global models with deforestation and desertification scenarios will be discussed. The section on "human impact on atmospheric composition" discusses the main causes of ozone depletion and its consequences, the increases of greenhouse gases during past centuries, and computer simulated temperature increases and changes in water cycle, terrestrial ecosystem, glacial, and geomorphological processes.
This is a multidisciplinary course suitable for both physical geography and environmental studies, and is also appropriate for other disciplines related to climate and environmental research.
Prerequisites:
Geography 1, Geography 5, or equivalent.
Text Book:
Andrew Goudie, 2000: The Human Impact on the Natural Environment. The MIT Press. Fifth Edition.
Nick Middleton: 1999: The Global Casino. An Introduction to Environmental Issues. Arnold. Second Edition.
Grading:
Home work (30%); midterm examination (30%); an abstract and abstract presentation (10%); and a final paper (30%).