Introduction to Environmental Geology
Environmental geology: Interaction of humans and the geologic
environment
Areas: Geologic hazards (earthquakes, floods, landslides)
Resources (e.g. water, fossil fuels, soils)
Environmental geologist uses Scientific method:
Makes observations in laboratory and/or in nature
Formulates hypotheses based on observations
Test hypothesis (example: see global warming)
Tools: various kinds of maps important
GIS: Geographic information systems
Digitally generated maps- superimposed on each other
E.G. map of soil type, superimposed on topography, superimposed on
population centers.
Population Dynamics
Carrying capacity: # of people Earth can support (maybe 10- 15 billion).
Current population about 6 billion.
Growth rate: birth-rate minus death-rate
Recent population growth due to better global health (lower deathrate).
Doubling time: Years it takes for population to double
Doubling time (years)
1500
330
100
44
Date
1 A. D.
1500
1830
1930
1977
Population
0.25 billion
0.5
1.0
2.0
4.0
Formula for doubling time: 70/% /growth rate
E.g. 2% growth rate: 70/2 – 35 years
Pop. growth in USA: mainly immigration
Japan: birthrate very low: population decrease predicted
Sustainable Society
Pass on natural resources to later generations:
conserve, share, re-cycle.
Oil predicted to become scarce either by year 2010 or 2030.
Need new energy source.
Environmental issues
Global warming: greenhouse gas effect
Certain gasses in atmosphere let heat in, but not out of atmosphere (do not
confuse with ozone depletion)
Greenhouse gases: CO2 most important;
Others: Methane (CH4); Nitrous oxide (N2O)
Atmosphere CO2: 175 - 280 ppm (pre-industrial revolution). Today 330 ppm.
Today highest in last 160, 000 yrs.
Evidence: Melting of glaciers (Table 1.3)
Rising sea level rising:
1) melting of ice,
2) expansion of ocean water due to Temp. increase
Soil degradation
Salt contamination in coastal areas – sea level rise
Acid rain- depletes soil of nutrients
Logging/deforestation: increases erosion by runoff.
Farming practices: increase soil erosion by wind/water
Fresh water
Limiting resource in terms of population growth
(no water, no food)
Fresh water only 3% of all water (including ice)
Major users: agriculture, industry, homes
Energy (or power)
Energy measured in Watts (units of work/time)
1000 watts = 1kW (kilowatt)
Electric bulb: 100 watts
Burn 10 100 watt bulbs for 1 year = 1 kilowatt-year
History of energy consumption with time:
Past: wood, coal, oil, natural gas,
Future: nuclear?, solar?, hydrogen?
END