Changes in systems may occur naturally or may be induced by humans. This presentation introduces Earth as a system. One of the most fruitful areas of environmental research remains the investigation of relationships between physical and biological processes on a global scale.

1. SYSTEMS AND CHANGE
Chapter 3 Environmental Science Part One
Mr. Thompson Environmental Science Systems and Change
1

2. LEARNING OBJECTIVES
•Why solutions to many
environmental problems
involve the study of systems
and rates of change.
•How positive and negative
feedback operate in a system.
Mr. Thompson Environmental Science Systems and Change
2

3. LEARNING OBJECTIVES CONTINUED
•What are the implications of exponential
growth and doubling time.
•That natural disturbances and changes in
systems such as forests, rivers, and coral
reefs are important to their continued
existence.
Mr. Thompson Environmental Science Systems and Change
3

4. LEARNING OBJECTIVES CONTINUED
•What an ecosystem is and why sustained life
on Earth is a characteristic of ecosystems.
•What the Gaia hypothesis is and how life on
Earth has affected the Earth itself.
•What the principle of uniformitarianism is and
how it can be used to anticipate future
changes.
Mr. Thompson Environmental Science Systems and Change
4

5. LEARNING OBJECTIVES CONTINUED
•Why the principle of environmental
unity is important in studying
environmental problems.
•How human activities amplify the
effects of natural disasters.
Mr. Thompson Environmental Science Systems and Change
5

6. UNDERSTANDING SYSTEMS
•How systems interact with each other.
•System – a set of components or parts
that function together to act as a whole.
i.e. your body is a system, your bedroom is
a system.
•The Earth is a system.
Mr. Thompson Environmental Science Systems and Change
6

7. TYPES OF SYSTEMS
• Open systems – is not generally contained within
boundaries and some energy or material (solid,
liquid or gas) moves into or out of the system. i.e. the
Ocean is an open system.
• Closed systems – no such movements take place.
Earth is a closed system with regard to material.
• Systems respond to inputs and have outputs. Your
body is a complex system.
Mr. Thompson Environmental Science Systems and Change
7

8. FEEDBACK
• Feedback occurs when the output of the system
also serves as an input and leads to further changes
in the system. i.e. human temperature regulation. If
you go out in the sun and get hot, the increase in
temperature affects your sensory perceptions
(input). If you stay in the sun, your body responds
physiologically. You are cooled by evaporating
water when you sweat. The cooling is output and
also input to your sensory perceptions.
Mr. Thompson Environmental Science Systems and Change
8

9. HOW EARTH WORKS AS A SET OF
INTERCONNECTED SYSTEMS
Mr. Thompson Environmental Science Systems and Change
9

10. HUMANS AFFECT THE EARTH SYSTEM
Mr. Thompson Environmental Science Systems and Change
10
• How we affect our environment
is important.
• Human activities increase and
decrease the magnitude and
frequency of some natural
Earth processes.
• As human population increases
a parallel increase in the extinction
of species has occurred.

11. HUMANS CHANGE THE EARTH
Mr. Thompson Environmental Science Systems and Change
11

12. PART TWO
Mr. Thompson Environmental Science Systems and Change
12

13. DIY BIOSPHERE
Mr. Thompson Environmental Science Systems and Change
13

14. ECOSYSTEMS
• A community of
organisms and its local
nonliving environment
in which matter
(chemical elements)
cycles and energy
flows.
Mr. Thompson Environmental Science Systems and Change
14

15. GAIA HYPOTHESIS
•Greek Goddess Mother Earth
•John Lovelock
•Life manipulates the
environment for the
maintenance of life.
Mr. Thompson Environmental Science Systems and Change
15

16. THE GAIA HYPOTHESIS
Mr. Thompson Environmental Science Systems and Change
16

17. STAGGERING AMOUNTS OF
ENVIRONMENTAL CHANGE
• In 10 years since launch,
Europe's Earth
observation
satellite data documents
changes in ozone,
pollution,
effects of natural
disasters
and more.
Mr. Thompson Environmental Science Systems and Change
17

18. HUMAN AMPLIFICATION OF
ENVIRONMENTAL CHANGE
• Natural change can
rearrange the
landscape almost
overnight by
earthquake, flood,
volcanic eruption or
hurricane.
• Catastrophe – an event
which damages people,
property and society.
Mr. Thompson Environmental Science Systems and Change
18

19. HUMAN ACTIVITIES POTENTIALLY
IMPACT NATURAL DISASTERS
•People had removed one-half of the forest of
Honduras.
•In addition, an 11,000 – km2 fire had damaged
the the region prior to the hurricane.
•Hillsides stripped of vegetation washed away
during the hurricane.
Mr. Thompson Environmental Science Systems and Change
19

20. GLOBAL WARMING
•Most changes
brought on by
human activity
involve rather
slow processes
with cumulative
effects.
Mr. Thompson Environmental Science Systems and Change
20

21. LESSONS LEARNED
•Land
rehabilitation
•Sustainable
development
•Maintenance
healthy
ecosystems
Mr. Thompson Environmental Science Systems and Change
21