teaching - Earth Science Teachers' Association

TEACHING EARTH SCIENCES ● Volume 26 ● Number 3, 2001
Earth System Science:
A Better Way to Teach Science Enquiry
RICHARD A. DUSCHL
This paper was delivered as the Keynote Lecture at the Annual Conference of the Earth Science
Teachers Association at Kingston University in September 2001. It provides an overview of the
context in which Earth System Science has emerged as the dominant perspective on global
issues. This then provides the platform for the consideration of the Earth System curriculum
frameworks which have been developed over the last decade. The lecture and this article are
based on the chapter by Duschl and Smith in “Subject-Specific Instructional Methods and
Activities”, Advances in Research on Teaching, Volume 8 (Duschl & Smith 2001).
Introduction
The second half of the 20th Century has been a time of
rapid change in the character of the Earth sciences. The
transition is one moving away from a focus on the surface
geology of mapping and mining and toward a focus
on global change and Earth systems (Mayer & Armstrong,
1990). A science once dominated by historical
types of explanations revealing the ‘story in the rocks’ is
slowly evolving into a causal modelling science for
making predictions (e.g., climate changes, Earthquakes,
volcanic eruptions, flooding, hurricanes) and understanding
how human activity effects global change.
Thus, not surprisingly, the information or subject matter
and the cognitive and the material tools needed to
engage in Earth science inquiry have shifted as well.
John McPhee elegantly captures the character of this
change in his book Rising From the Plain. The story is
about the geology of Wyoming told through the experiences
of a high country, Rocky Mountain regional field
geologist – Dave Love. For Love, geology was a kind of
story telling. Through experiences of touching different
geologic structures, you piece together the implied tectonics;
i.e., the story in the rocks. He, like many other
geologists, relate to the Hindu fable of blind men and
the elephant (each individual feeling a different part of
the elephant comes to different opinions of what it is).
But field geologists like Dave Love are a dieing breed.
In recent years, the number of ways to feel the elephant
has importantly increased. While science has
assimilated such instruments as the scanning transmission
electron microscope, the inductively coupled plasma
spectrophotometer, and the 39 Ar/ 40 Ar laser microbe
. . . .the percentage of geologists has steadily diminished
who go out in the summer and deal with rock, and the
number of people has commensurately risen who work
the year around in fluorescent light with their noses on
printouts. (McPhee 1986, p 146).
Feeding facts and fragments of the Earth into laboratory
machines is referred to as “black-box geology” carried
out by “analog geologists” (McPhee 1986, p 146).
At the beginning of the 1900s and well into the 20th
Century geology and the other Earth sciences were
essentially atheoretical disciplines. The theories and
paradigms that influenced geological inquiry came
from the physical sciences – i.e., physics and chemistry.
In the words of Thomas Kuhn (1970), geology and the
other Earth sciences (e.g., oceanography, climatology,
planetary geology, meteorology) were immature sciences
since they lacked an organizing paradigm.
The rapid changes in technology during the 20th
Century have significantly impacted all the sciences.
But the impacts on the Earth and geological sciences
were nothing short of revolutionary. For during this
past century the geological sciences made the transition
from an immature science to a mature paradigm-driven
science. Furthermore, observational techniques, tools
and guiding conceptions (e.g., theoretical frameworks)
have evolved and along the way shifted what comes to
count as doing Earth science research and inquiry. In
brief, descriptive inquiry approaches to the Earth sciences
have given way to model-based inquiry
approaches. The focus on local mapping and mining,
and human-observational techniques have yielded to
global mapping and modelling, and instrument-observational
techniques. New tools like websites and CD-
Roms have literally made it possible for students of the
Earth sciences to have direct access to the raw data and
models being used to study planet Earth.
Consider the release of classified satellite imagery
data. For approximately 30 years, Landsat satellites
snapped pictures of the surface of the Earth. Employing
5 bands of electromagnetic radiation (3 visible light
bands and 2 infrared light bands), details about the surface
of the Earth are revealed. The amount of information
is enormous and computer technologies have now
made this data available for public use. Schools with
online capabilities can access the data. Such databases
allow local, regional, and global groups to conduct
inquiries about environmental and climatic changes.
Consider the Terra mission that monitors the vital
signs of the planet (King & Herring, 2000). Terra is a
89 www.esta-uk.org