In this lecture you will be introduced to Earth system science a new holisitic approach to studying the Earth as a whole system of many interacting parts.

1. The Earth System
The Blue Planet: Chapter 1

2. Outline
• Earth System Science
• Systems
• Earth System Reservoirs
• Dynamic Interactions Among
Reservoirs
• How Science Works

3. Earth System Science
• Earth system science is the new
holisitic approach to studying the Earth
as a whole system of many interacting
parts
– The ocean -Soils
– The atmosphere -Plants
– The continents -Animals
– Lakes and rivers

4. Earth System Science
• Requires observations of Earth at
various scales
• The quintessential tool for making these
observations is remote sensing with
satellites
• Geographic Information Systems
provide ways for scientists to store and
analyze vast amounts of data

5. Earth System Science

6. Outline
• Earth System Science
• Systems
• Earth System Reservoirs
• Dynamic Interactions Among
Reservoirs
• How Science Works

7. Systems
• A system is any portion of the universe
that can be isolated from the rest for the
purpose of observing and measuring
changes
• By observing and measuring changes,
systems can be used to study complex
problems

8. Systems

9. Systems
• A model is a representation of
something, typically a simplification of a
complex original
• We can build models of processes,
which can represent some of Earth’s
systems

10. Systems

11. Systems
• A box model is a simple graphical
representation of a system
• It can show essential features
– The processes and rates by which matter
or energy enters and leaves the system
– The processes and rates by which matter
or energy moves within the system
– The amount of matter or energy in the
system and its distribution

12. Systems

13. Systems
• A key to understanding the Earth
system is to measure how volumes and
exchanges of materials and energy
between Earth’s reservoirs change over
time
• The challenge is to determine why the
changes happen, and how quickly

14. Systems
• The amount and of energy or matter that is
transferred is called flux
• The places where energy or matter is stored are
called reservoirs
– If the flux into a reservoir is greater than the flux out,
that reservoir is a sink
– If the flux into a reservoir is less than the flux out, that
reservoir is a source
• The length of time energy or matter spends in a
reservoir is its residence time, when this time is
so great that matter is isolated for very long
periods, it is called sequestration

15. Systems
• Earth comprises four vast reservoirs
with constant flows of energy and
matter among them
– The atmosphere
– The hydrosphere
– The biosphere
– The geosphere
• As a whole, Earth is essentially a closed
system

16. Systems

17. Systems
• Two important implications of Earth
being a closed system are
1. The amount of matter in a closed system
is fixed and finite
2. If changes are made in one part of a
closed system, the results of those
changes eventually will affect other parts
of the system

18. Outline
• Earth System Science
• Systems
• Earth System Reservoirs
• Dynamic Interactions Among
Reservoirs
• How Science Works

19. Earth System Reservoirs
• The place where Earth’s four reservoirs
interact most intensively is a narrow
zone called the life zone
• Conditions favorable for life are created
by interactions between the lithosphere,
hydrosphere and atmosphere, and
modified by the biosphere

20. Earth System Reservoirs

21. Earth System Reservoirs
• The Geosphere
– Is the solid earth
– Composed mainly of rock and regolith
– Where energy that comes into the Earth
system from outside sources meets energy
that comes from within the planet
– Energy sources combine and compete to
build up and wear down the materials of
Earth’s surface

22. Earth System Reservoirs
• The Hydrosphere
– The totality of Earth’s water
– Includes oceans, lakes, streams,
underground water, and all snow and ice
– The perennially frozen parts of the
hydrosphere are collectively the cryosphere
– The hydrosphere and the atmosphere store,
purify, and continually redistribute water

23. Earth System Reservoirs
• The Atmosphere
– The mixture of gases that surrounds Earth
– Predominantly Ni, O2, Ar, CO2, and H2O
– In the context of the planet it is a very very
thin layer, but it protects life from damaging
solar radiation, is the reservoir for oxygen
and carbon dioxide
– It is the outer boundary of the Earth system

24. Earth System Reservoirs

25. Earth System Reservoirs
• The Biosphere
– Includes all of Earth’s organisms and
matter that has not yet decomposed
– The biosphere greatly affects every other
of Earth’s systems
• Photosynthesis
• Oxygen as a highly reactive gas

26. Earth System Reservoirs
• The Anthroposphere
– The “human sphere”
– Comprises people, their interests, and their
impacts on the Earth system
– The part of the natural system that has
been modified by humans
– Includes the technosphere, specifically to
technology, machines, and the built
environment

27. Outline
• Earth System Science
• Systems
• Earth System Reservoirs
• Dynamic Interactions Among
Reservoirs
• How Science Works

28. Dynamic Interactions Among
Reservoirs
• Because energy flows freely into and out
of systems, all systems respond to inputs
and, as a result, have outputs
• A special kind of response, feedback,
occurs when the output of the system also
serves as an input
– Negative feedback: the system’s response is
in the opposite direction of initial input
• Often self-limiting or self-regulating

29. Dynamic Interactions Among
Reservoirs
• Positive feedback: an increase in output
leads to a further increase in output
– Vicious cycle
– Destabilizing

30. Dynamic Interactions Among
Reservoirs

31. Dynamic Interactions Among
Reservoirs
• The constant movement of material
from one reservoir to another is called a
cycle
• Natural cycles are not simple, and exist
in a state of dynamic equilibrium
• There are many important Earth cycles

32. Dynamic Interactions Among
Reservoirs
• The Hydrologic Cycle
• The Energy Cycle
• The Rock Cycle
• The Tectonic Cycle
• Biogeochemical Cycles

33. Dynamic Interactions Among
Reservoirs

34. Dynamic Interactions Among
Reservoirs
• Humans involve or affect natural cycles
• Significant changes are now taking
place in many Earth reservoirs, as a
result, many are changing in
unexpected ways
• Scientists have coined a term to
describe changes produced in the Earth
system as a result of human activities:
global change

35. Dynamic Interactions Among
Reservoirs

36. Outline
• Earth System Science
• Systems
• Earth System Reservoirs
• Dynamic Interactions Among
Reservoirs
• How Science Works

37. How Science Works
• Earth system science, like all other
forms of science, advances by
application of the scientific method
• The scientific method is based on
observations and the systematic
collection of evidence that can be seen
and tested by anyone with resources

38. How Science Works

39. How Science Works
• Scientists start with an observation and seek to
acquire evidence about it through measurement
and experimentation
• Scientists try to explain their observations by
developing a hypothesis
• Once a hypothesis has been examined and found
to make successful predictions and withstand
numerous tests, it may become a theory
• Eventually, a theory or group of theories whose
applicability has been decisively demonstrated,
may become a law or a principle

40. How Science Works

41. How Science Works
• The fact that nothing is absolutely
certain in nature is not problematic for
scientists, but can be difficult for non-scientists
to comprehend fully
• It is important to understand that
uncertainty does not imply a lack of
scientific knowledge or understanding