evr- unique earth

1. Temperatures that permit liquid water- The unique characteristics of water

2. Oxygenated atmosphere- The unique characteristics of oxygen

What 2 things are needed for complex life? Why?

A molecule containing two hydrogen atoms (+) and one oxygen atom (-)

H20 (Water)

The positive (hydrogen) and negative (oxygen) poles of the water molecule can each form weak bonds with negative or positive (respectively) ions

What makes water an excellent solvent?

H+. OH-

Water molecules can break apart into ___ and ___ ions

Molecule

Two or more atoms bonded together

Ion

Electrically charged (positive or negative) molecules or atoms

energy

When positive and negative ions combine they release _____

Oxygen is highly attracted to electrons, and like to combine with other molecules in process that release energy

Oxygen is a highly reducing gas. What does this mean?

Organisms store energy in molecules (fats and sugars) that release energy when combined with oxygen

How is oxygen’s highly reducing gas characteristics applied to organisms?

21%

Oxygen gas comprises___ of Earth’s atmosphere

True

T/F: Oxygen gas was almost completely absent from the early Earth’s atmosphere

System

Set of components or parts that function together to act as a whole; responds to inputs and outputs

1. Open System

2. Closed System

3. Isolated System

3 Types of Systems

Open System

Energy or material moves into or out of system

Closed Sysetm

No material moves into or out of the system, but energy (e.g., heat) can move into or out of the system

Isolated System

no heat or energy moves into or out of the system

Static System

System with fixed condition; stays in that condition

Dynamic system

A system that changes continuously over time

Dynamic Equilibrium

A steady state balance between continuing processes; not maintained for very long

True

T/F: Natural systems tend to move towards dynamic equilibrium without influence of people

Average residence time

How long, on average, a quantity of something will remain in a reservoir of a system

Reservoir size and rate of input or output of material

Resident Time depends on

Feedback

When one part of the system changes, and those changes affect another part of the system, which affects the impact of the first change

Negative Feedback

an increase in output leads to a later decrease; self-regulating or stabilizing

Positive feedback

An increase in output leads to a further increase in the output; destabilizing

Positive; it amplifies the reaction, leading to a more impactful affect as opposed to dampening the effect

Is positive or negative feedback typically more serious for the envoirnment?

Stable System

A system that has a condition that it remains in unless disturbed, and returns to that same condition if disturbed from it and the cause of the disturbance stops (negative feedbacks)

Linear Response, Non-linear response, Lag time

System Response Concepts

Linear response

If you add the same amount of anything to a compartment in a system, the change will always be the same

Nonlinear response

A response that shows the effect of adding a specific amount of something changes, depending on how much has been added beforehand

Lag Time

The delay between a cause and the appearance of its

effect

Recurring relationships can be represented with a small number of

graphs

• Include responses of individual organisms, populations and species, &

entire ecosystems

• Each graph

– Has a mathematical equation that can explain the curve

– But, it is the shape of the graph and what that shape represents that are the keys

to understanding environmental systems

Characteristics of System Response Concepts

Linear Growth

add a certain amount of individuals each year; plotted on a graph with form a line

Exponential growth

Add a fixed proportion of the population each year (e.g. doubling every 20 years); plotted on a graph with form a j-shaped curve

1. Rate of growth measured as a percentage

2. Doubling time in years

2 Factors of Calculating Exponential Growth

positive, incompatible

Exponential growth is____ feedback and _____ with sustainability

Negative Exponential Curve

Equivalent to removing a fixed proportion of something over a specific

length of time; takes a very long time to return to background conditions

The Saturation Curve (represents the boundary where a system reaches maximum capacity)

What does this graph depict?

Overshoot and Collapse

What does this graph depict?

Environmental Unity

States it is impossible to change only one thing in the ecosystem; Earth and its ecosystems are complex entities in which any action may have several effects

Unfiromitarianism

By James Hutton (Father of Geology); The geological and biological processes presently forming and modifying Earth are the same now as they were in the past, and vice versa

Geologically short-lived landforms will continue to appear and disappear due to natural disasters

What does the concept of Uniformitarianism include regarding land formations?

Environmental problems are often complex, involving a variety of

linkages among the major components and within each componen

How are environmental problems/changes complex?

Gaia Hypothesis

Life manipulates the environment for the maintenance of life; the planet is capable of physiological self-regulation

The Earth’s atmosphere was primarily nitrogen and carbon dioxide until the evolution of cyanobacteria, which undergo photosynthesis, taking in carbon dioxide releasing oxygen into the atmosphere, gradually decreasing carbon dioxide and increasing oxygen

What caused the Earth’s atmosphere to become oxygenated?

• Decreased oxygen concentrations would lead to decreased respiration by animals – and oxygen would begin to increase again

• Increased oxygen concentrations would sustain higher frequencies of wildfires – and oxygen would be used up in the fires

How is Earth’s oxygen concentration is controlled by multiple negative feedbacks?

Refer to slides for real life examples of positive/negative feedbacks in Earth’s temperature regulation!!!!

Yes