Transcript Earth Spheres

The Earth as a
System
Earth’s Spheres
Earth System Science (ESS)
• The study of the interactions
between and among events and
Earth’s spheres
• A relatively new science (1988)
Earth’s Sphere
• Atmosphere
• Hydrosphere
• Lithosphere
• Biosphere
• Cryosphere
• Anthrosphere
Atmosphere
• A gaseous sphere
and it envelopes the
Earth,
• Consists of a mixture
of gases composed
primarily of nitrogen,
oxygen, carbon
dioxide, and water
vapor.
Hydrosphere
• All of the
water on
Earth
• 71% of the
earth is
covered by
water and
only 29% is
terra firma
Lithosphere
• The Earth's solid
surface, often
called the crust of
the earth. It
includes
continental and
oceanic crust as
well as the
various layers of
the Earth's
interior.
Biosphere
• All life on earth,
including man,
and all organisms.
• The life zone on
our planet
distinguishes our
planet from the
others in the solar
system.
Cryosphere
• The portion of
the Earth's
surface where
water is in a solid
form
• Snow or ice:
includes glaciers,
ice shelves,
snow, icebergs,
and arctic
climatology
Anthrosphere
• Man and his
direct
ancestors,
hominids.
• The human
population, it’s
buildings,dams,
and other
constructions.
Interconnected Spheres
• Spheres are closely connected
• Changes are often chain reactions
• A change in one sphere results in
changes in others - called an event
– Forest fire destroys plants in an area
• Interactions between spheres
– No plants => erosion
– Soil in water => increased turbidity
– Turbidity => impacts water plants/animals
Event <=> Sphere
• Causes & Effects
• Interactions
• Event <=>Sphere
• Sphere<=>Sphere
ESS Analysis
• Events
– Cause-effect events (usually not
simple)
– Interactions (weblike)
– Natural events
• Earthquake, hurricane, forest fires
– Human caused events
• Oil spill, air pollution, construction
ESS Analysis
• What spheres caused the event?
Sphere
Event
• What are effects of the event on the
spheres?
Event
Spheres
• How do changes in one sphere impact
on other spheres?
Sphere
Sphere
Understanding Interactions
• Global implications
• Helps people predict outcomes
• Preparation for natural disasters
• Environmental impacts of human
activities
1.The Earth System behaves as a
single, self-regulating system with
physical, chemical, biological, and
human components. The
interactions and feedbacks
between the component parts are
complex and exhibit multi-scale
temporal and spatial variability.
The understanding of the natural
dynamics of the Earth System has
advanced greatly in recent years and
provides a sound basis for evaluating
the effects and consequences of
human-driven change.
2. Human activities are significantly
influencing Earth's environment in
many ways in addition to greenhouse
gas emissions and climate change.
Anthropogenic changes to Earth's
land surface, oceans, coasts and
atmosphere and to biological
diversity, the water cycle and
biogeochemical cycles are clearly
identifiable beyond natural variability.
They are equal to some of the great
forces of nature in their extent and
impact. Many are accelerating. Global
change is real and is happening now.
3. Global change cannot be understood
in terms of a simple cause and effect
paradigm. Human-driven changes
cause multiple effects that cascade
through the Earth System in complex
ways.
These effects interact with each other
and with local- and regional-scale
changes in multidimensional patterns
that are difficult to understand and
even more difficult to predict.
4. Earth System dynamics are
characterized by critical thresholds and
abrupt changes. Human activities
could inadvertently trigger such
changes with severe consequences for
Earth's environment and inhabitants.
The Earth System has operated in
different states over the last half
million years, with abrupt transitions
(a decade or less) sometimes
occurring between them. Human
activities have the potential to switch
the Earth System to alternative modes
of operation that may prove
irreversible and less hospitable to
humans and other life.
The probability of a human-driven
abrupt change in Earth's environment
has yet to be quantified but is not
negligible.
5. In terms of some key environmental
parameters, the Earth System has
moved well outside the range of the
natural variability exhibited over the
last half million years at least
The nature of changes now
occurring simultaneously in the
Earth System, their magnitudes and
rates of change are unprecedented.
The Earth is currently operating in a
no-analogue state.