Chapter 1: Fundamentals of Environmental Geology

Introduction

• three factors make life on earth possible;

  • temperature is in range for all three states of water to exist

  • the planet can retain its atmosphere so that water can cycle through all three states

  • there is a natural mechanism to remove CO_2 from the atmosphere, primarily the formation of carbonate rocks like limestone which prevents the build up of greenhouse gases and rising temperatures as what happened to Venus

• Humans only existed for the last 200,000 years vs the 4.5 billion year earth. Despite this, we have a profound impact on the earth.

• we can understand and modify our environments to suit our needs (nomadic→ agricultural settlements → natural disaster risk management → mineral and energy resource use → industrial revolution → modern day)

• unintended consequences and byproducts of advancement

• the tragedy of the commons: self-interest of individuals results in the destruction of a common good/resource

• Disconnection from the natural environment (primarily urban population) combined with the tragedy of the commons → environmental problems

What is Geology?

• geology is the study of the solid earth (materials that make up the planet and processes that shape it)

• geologists find and study important minerals and resources to make modern conveniences possible

• also risk management for natural disasters

• two subtypes; physical and historical geology

  • physical: study of the solid earth and process that shape and modify the planet.

  • historical: interpreting the past through information in geologic rock record.

  • newer; environmental geology - address issues from interactions of humans with the geological environment

Scientific Inquiry

• science is the systematic and logical process to explain the physical world

• a method using data to discover how the natural world operates

• how science operates

  • assumes that the physical world behaves in a predictable and consistent way

  • pattern recognition; repeated phenomenon like tides or volcanic eruptions.

  • scientific method: gather factual data/observations on a pattern that can be physically measured, propose an explanation (hypothesis) or several (multiple working hypotheses), then prove it

  • theory vs hypothesis, different concepts. a theory describes the relationship between accepted hypotheses to describe a broader idea

  • the central theory of geology is the theory of plate tectonics that explains how the Earth’s crust is broken into plates which move due to forces from the internal heat of the planet.

  • Influences the shape of continents and ocean currents → strong effect on the global climate and biosphere

  • despite meaning an educated guess in common speech, scientific theories are rigorously tested and widely accepted

  • a law is a phenomenon that is completely regular and predictable. like the law of superposition (in a sequence of layered rock, the top layer is the youngest and the bottom is the oldest)

  • laws and theories are expanded and changed as new research is done

• Science and Society

  • specialization advances science and improves lives

  • prediction come with a degree of uncertainty

  • fear of change plus ignorance of how science benefits us leads to resistance to important discoveries and changes

  • some cast intentional doubt on science in order to support their own interests (Tabaco industry, global climate change opposers)

  • junk science used to confuse and delegitimize → bias in data and passing peer review process

Environmental Geology

• there are two geology issues; hazards and resources

• geologic hazards are any geological condition whether natural or artificial that potential risks human life or property. (earthquakes, volcanic eruptions, floods, pollution).

• Some hazards are important processes in maintaining a habitable environment. human activity can also increase the risk of a hazard (minimizing flooding in one area can cause flooding to increase in another area)

• Pollution is a hazard because it effects important ecosystems and human health. Though it can occur naturally it is mostly caused by human activity

  • mercury from coal burning → creates dangerous compounds when combined with atmospheric CO_2 and moves through the food chain.

  • Greenhouse gases from fossil fuel burning → current amount disrupts the natural equilibrium

• earth resources: water soil, mineral, and energy

  • maintaining adequate supplies and minimizing pollution

  • Freshwater and soil are most important as they are critical to agricultural food supply

  • erosion, lack of water supply, and sediment pollution are big issues

  • overreliance on nonrenewable energy and mineral resources (iron, copper, limestone, etc)

  • some minerals are so common that they’re virtually inexhaustible but others like cobalt and chromium are very important and relatively rare.

  • Energy resources like crude oil is critical and quickly exhausted

Environmental problems and time scales

• time scale influences risk perception (earthquakes are fast and have immediate effects while pollution is slow and the effects are hard to see in a given stretch of time)

• some sporadic events are once-in-a-lifetime so when the last to experience it die off, we become complacent and don’t take steps to minimize risk. Sporadic events that happen frequently are more likely to be taken in to account

• Geologic time

  • geologic time scale classifies rocks according to relative and chronological age.

  • absolute age is the actual age of a rock and was impossible to quantify

  • until it was discovered you could use the half-life of uranium into lead atoms to calculate it.

  • radiometric dating are dating techniques using radioactive elements and their decay products (lead-uranium dating)

  • since the earth is so old, analogies are used to describe geological time, like thinking of history as a full calendar year. In this analogy, dinosaurs existed for only 15 days, and humans for only 23 minutes

  • catastrophism theorized that the earth’s features were formed from sporadic events (early formation of volcanic islands)

  • uniformitarianism explains that the features were formed by slow processes over long periods of time (creation of the grand canyon).

• Environmental risk and human reaction

  • environmental risk is the chance of a natural process or event producing negative consequences for an individual or society

  • risk level is the probability of an event vs it’s consequences - there is a small chance of a mile wide asteroid hitting the earth but the consequences would be huge

  • risk management is the steps taken to identify and reduce a specific risk. Getting in a car accident (risk), and wearing a seatbelt (minimize impact) and drive defensively (minimize chance)

  • how people respond to risk is affected by the time scale of the event/process

  • incremental process generates small changes over time with little consequence in the day-to-day

  • sporadic processes are somewhat random and commonly called hazards. They produce sudden and dramatic changes. Ones with extreme consequences are called disasters. Despite being random they occur at somewhat regular intervals

  • events that occur regularly and more frequently are taken into account in risk management, but events that don’t happen very frequently (once in a lifetime) aren’t which results in huge catastrophes

  • incremental processes are hard to address because of how hard it is to recognize that they are an issue

Earth as a system

• considerations in environmental risk management; time scale, humans as participants in a complex global system

• specialization keeps scientists from seeing the larger picture sometimes

• there is growing interest in interconnections of scientific fields and the interconnected nature of the earth’s systems

• earth systems science studies earth science as a dynamic system of the four subsystems; atmosphere, hydrosphere, biosphere, and geosphere.

• changing one subsystem can affect every subsystem (damming the Columbia river)

• deforestation; removes the biosphere which in turn degrades the geosphere through erosion which pollutes the hydrosphere and atmosphere through the water cycle and increased greenhouse gas effect, etc, etc

The earth and human population

• population growth

  • growth is categorized as linear or nonlinear (exponential)

  • industrialization and advanced medicine led to rapid human population growth in the last few hundred years.

  • Is there a limit to human population growth?

• limits to growth

  • Malthus - linear food production growth compared to exponential population growth, once humans hit the carrying capacity/outstripped food production, there would be cycles of famine and prosperity

  • innovation/the green revolution increased food production so this prediction never came true (as of now)

  • urbanization/urban sprawl is the increase in size of cities and percentage of a population that lives in them

  • second wave malthus ideology in the 70s → population rises, reaches the carrying capacity, everything crashes and population levels out at a new carrying capacity.

  • infinite population/economic growth is impossible; topsoil erosion, water supplies, crude oil supplies, etc

• sustainability

  • the ability of a system to sustain itself indefinitely

  • the ability to live within the earth’s capacity to provide resources and leave enough for future generations (not spending more than we’re saving)

  • demographic transition; developing (high birth rate high death rate, solid working population)→ early development (low death rate high birth rate still a high working population)→ final developed (low death rate and low birth rate, low working population). Stable population to population boom to population stability/fall.

  • developed countries overly rely on developing nations to support their populations while the increased population of developing nations stresses global and national resources.

• Ecological footprint

  • the concept of how much productive land is needed to support a single person

  • currently approx 2.8 hectares (size of a soccer field) per person

  • people in developed nations have a high footprint while developing is relatively low.

  • the current footprint is 70% larger than what the earth can support and the current population is is unsustainable

  • overshoot and collapse is the most realistic outcome at the current course

Environmentalism

• 60s and 70s early environmentalism movement (clean air and water acts)

• misconception of environmentalism as valuing nature over humanity → in actuality it’s protecting humanity from themselves. The earth will recover from what we’ve done, we won’t