Lecture 1
Introduction to Environmental Geology
I. What are Geology and Environmental Geology?
Geology - the study of the rocks that make up the earth's surface and interior, and the natural processes that shape the earth's surface over time. These processes include plate tectonics (i.e. continental drift), earthquakes, volcanism, landslides, and erosion, and other processes related to movement of the earth's surface or interior.
Environmental Geology - The study of the interactions between geologic processes and the surface and near-surface environment, particularly where such interactions are influenced by or otherwise impact living organisms.
Environmental geology as "applied" geology - brings collective geologic knowledge to bear on problems that are important to people. Examples will be provided throughout the course.
Why is Environmental Geology Important?
Concept of "Spaceship Earth"- near zero net flux of material onto and off from planet implies that resources are finite. In the past 20 years, the sheer numbers of humans and their increasing demand for material goods have done the following:
II. Collision Course of Humans and the Environment
One emphasis of this course is the rapid increase in human population and migration of people into geologically hazardous environments about which they understand little or nothing. Examples include building in areas prone to hurricanes (i.e. 100,00 people left southern Florida in the year after Hurricane Andrew blasted Dade County), urban development in earthquake-prone regions such as Los Angeles County, overbuilding in the flood plains of major rivers, develpment in areas of high coastal erosion, and building in areas where the land surface is unstable. These topics concern the exposure of large populations to infrequent, large-scale catastrophes.
Some of this course will focus on the slow, small-scale processes such as loss of top-soil through poor farming practices and the resultant decline in food production that affects many people. We often fail to notice or heed subtle warning signs from our environment until they reach crisis proportions and begin to degrade the quality of life of many more people than are ever affected by catastrophic events.
Population now stands at 5.6 billion, over double that of 1950. It took humanity until 1830 to reach a total population of 1 billion, 1930 to reach 2 billion (100 year interval), 1960 to reach 3 billion (30 year interval), 1975 to reach 4 billion (15 year interval), 1986 to reach 5 billion (11 years), and ~1998 to reach 6 billion (12 years). Every year, ~90 million new people must be supported, equivalent to a nation the size of Mexico. The additional resources required to sustain the additional people at even a minimal level of existence is staggering. Since 1984, global grain production has increased at a level of 12 million tons per year, only one-third the 38 million tons per year of additional grain required by existing population growth over the same period.
Even as population increases, requiring more food, clean water, and resources, the space required by and waste generated by additional people takes the farmland required to feed them, drives species into extinction, impoverishes our biological heritage, and pollutes our environment. Current estimates are for 25% of all species to go extinct in the next few decades. Such a loss of biological diversity has been exceeded only once in the earth's 4 billion year history.
Stanford U. biologists estimate that earth's potential annual production of all biological matter is 150 billion tons. Man has directly destroyed 12% of that through pollution, urbanization, and deforestation, and utilizes over 25% of the remainder directly for food and other material production. The human species thus now diverts 40% of planetary biological production for its own use, raising serious questions about what we are leaving for other species.
Ultimately, everyone must understand the term "carrying-capacity", which is the number of people in a given area that can be supported by its environment at some predefined standard of living. If we were to strive for a standard of living comparable to that in the U.S., the earth has enough resources to support roughly half the present global population of 5.6 billion. At present, as many as 40% of the people on earth live in poverty and the earth's natural resource base is so diminished and over-exploited that the prospect of increasing production enough to give everyone an adequate standard of living often seems dismal.
The encroachment of humanity on wildlife habitat and general decrease of open, quiet space raises serious philosophical questions about the obvious tradeoffs between maximum carrying capacity and the right of other species to exist as well as the innate human need for undisturbed, quiet natural places.
III. Teaching Goals
Facing these gloomy statistics, why aren't we all just sipping margaritas on the beach and waiting for the end of the world? Because it is human nature to face challenges. For us, the challenge this semester is to give you a much better understanding of important physical processes in geology, their impacts on humans, and ways in which humans can mitigate natural hazards. We also will discuss resource issues that I believe will dominate the political and social arena during our lifetimes, and we'll discuss the positive role that individuals and institutions such as the government can play in issues regarding resource conservation and hazard mitigation.