r 3 earth’s environmental systems

3 Earth’s Environmental Systems C

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PT

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The Gulf of Mexico’s Dead Zone

• Nutrient-rich runoff causes plankton blooms and hypoxia—low oxygen levels—in the Gulf of Mexico.

• Hypoxia kills or displaces marine organisms, causing a decline in the fisheries and the fishing industry.

• U.S. government and farmers debate the need to cut down on fertilizer use.

Talk About It Do you think the distance between the source of the nitrogen and phosphorus and the dead zones themselves makes it difficult to manage this problem? Why or why not?

Lesson 3.1 Matter and the Environment

Water’s abundance is a primary reason there is life on Earth.

Atoms and Elements

• Atoms are the basic unit

of matter.

• Nucleus: Contains

protons and neutrons

• Electrons: Move around

the nucleus

• An element is a

substance that cannot

be broken down into

other substances. Did You Know? There are 92 elements

that occur naturally, and scientists have created about 20 others in labs.


Bonding

• Atoms combine by bonding:

• Covalent bonds: Electrons are shared.

• Ionic bonds: Electrons are transferred.

• Molecule: Two or more atoms joined by covalent bonds

• Compound: Substance composed of atoms of two or more different elements


Covalent bonding

Ionic bonding

CHNOPS – carbon hydrogen nitrogen oxygen phosphorus and sulfur make up approximately 98% of living organisms.

Heavy Metals – lethal to living organisms

• Build up and stay in the tissues

• As – arsenic

• Hg – mercury

• Pb - lead

Table 2-1, p. 38

Organic and Inorganic Compounds • Organic compounds:

Consist of covalently bonded carbon atoms and often include other elements, especially hydrogen

• ALL organic compounds contain 2 or more carbon atoms with one exception

• Methane CH4

• Hydrocarbons: Organic compounds, such as petroleum, that contain only hydrogen and carbon

• Inorganic compounds: Lack carbon-to-carbon bonds


Organic compounds include natural gas,

petroleum, coal, and gasoline.

•Mixtures can be solids, liquids, or gases.

SOLIDS

•Has definite volume

•Has definite shape

LIQUID

•Has definite volume •No definite shape – will

take the shape of its

container

GASES

•No definite volume or shape

•Will fill the volume and

take the shape of its

container

Macromolecules

• Large organic compounds that are essential to life

• Proteins: Serve many functions; include enzymes

• Nucleic Acids: Direct protein production; include

DNA and RNA

• Carbohydrates: Provide energy and structure;

include sugars, starch, and cellulose

• Lipids: Not soluble in water; many functions;

include fats, waxes, and hormones


Water • Water is required by all living things for survival.

• Hydrogen bonding gives water many unique properties:

• Cohesion – Water is sticky

• Resistance to temperature change – Keeps England warm

• Less dense when frozen – ice floats

• Water likes to dilute and dissolve.

• Osmosis – movement of water

• Polar molecule breaks many

bonds – salt and sugar

dissolve in water


What if lakes froze from the

bottom up?

Frontier Science, Sound Science, and Junk Science

Frontier science has not been widely tested (starting point of peer-review).

Sound science consists of data, theories and laws that are widely accepted by experts.

Junk science - a term for faulty scientific research, data, and claims created for financial or political gain – speculation presented as scientific information or research or data that has been skewed to reflect the beliefs or claims of the researcher.

Dihydrogen monoxide banning video http://www.youtube.com/watch?v=UXZRBJYX__E

http://www.youtube.com/watch?v=UXZRBJYX__E

Junk science is presented as sound science without going through the rigors of peer-review.

http://www.freedomforfission.org.uk

/deb/irrational.html

http://www.freedomforfission.org.uk/deb/irrational.html

http://www.freedomforfission.org.uk/deb/irrational.html

http://www.mitosyfraudes.org/Calen/correlaEng.html

http://www.mitosyfraudes.org/Calen/correlaEng.html

New satellite

images from

the European

Space Agency

show massive amounts of ice

are breaking

away from an

ice shelf on the

western side of the Antarctic

Peninsula,

researchers

said

Wednesday.

April 29,

2009 http://www.usnews.com/articles/sci

ence/2009/04/29/antarctic-ice-shelf-

collapse.html

New

measurement

s show the ice

in West

Antarctica is

thickening,

reversing

some earlier

estimates that

the sheet was

melting.

Despite reports to the contrary, ice in the Antarctic is growing

in area and density and has been consistently doing so for at

least 30 years now. Western Antarctica has shed several ice

shelves over time, but Eastern Antarctica has grown greatly

in the same time.

04/22/2009 02:09 PM http://www.foxnews.com/story/0,2933,517035,00.html

http://www.foxnews.com/story/0,2933,517035,00.html

How marvelous. And what are those inaccuracies?

The film claims that melting snows on Mount Kilimanjaro evidence global warming. The Government's expert was forced to concede that this is not correct.

The film suggests that evidence from ice cores proves that rising CO2 causes temperature increases over 650,000 years. The Court found that the film was misleading: over that period the rises in CO2 lagged behind the temperature rises by 800-2000 years.

The film uses emotive images of Hurricane Katrina and suggests that this has been caused by global warming. The Government's expert had to accept that it was "not possible" to attribute one-off events to global warming.

The film shows the drying up of Lake Chad and claims that this was caused by global warming. The Government's expert had to accept that this was not the case.

The film claims that a study showed that polar bears had drowned due to disappearing arctic ice. It turned out that Mr Gore had misread the study: in fact four polar bears drowned and this was because of a particularly violent storm.

The film threatens that global warming could stop the Gulf Stream throwing Europe into an ice age: the Claimant's evidence was that this was a scientific impossibility.

The film blames global warming for species losses including coral reef bleaching. The Government could not find any evidence to support this claim.

The film suggests that the Greenland ice covering could melt causing sea levels to rise dangerously. The evidence is that Greenland will not melt for millennia.

The film suggests that the Antarctic ice covering is melting, the evidence was that it is in fact increasing.

The film suggests that sea levels could rise by 7m causing the displacement of millions of people. In fact the evidence is that sea levels are expected to rise by about 40cm over the next hundred years and that there is no such threat of massive migration.

The film claims that rising sea levels has caused the evacuation of certain Pacific islands to New Zealand. The Government are unable to substantiate this and the Court observed that this appears to be a false claim.

Acids, Bases, and pH

• The separation of water

molecules into ions causes

solutions to be acidic, basic,

or neutral.

• The pH scale measures how

acidic or basic a solution is.

• pH of 7—Neutral: Equal

concentrations of H+ and OH-

• pH below 7—Acidic: Relatively

high concentration of H+

• pH above 7—Basic: Relatively

high concentration of OH-


REMEMBER – this is a logarithmic scale!!!!!

Figure 2-5

pH

• The measure of the acidity of a solution – the amount of H+ ions present.

• Neutral solution pH = 7

• Acidic solutions pH = 0-6.999

• Alkaline (basic) solutions pH = 7.4-14

• pH scale is a logarithmic scale • What is the difference between a substance with a pH of 6

and a pH of 4?

We Cannot Create or Destroy Matter

• Law of conservation of matter

• Whenever matter undergoes a physical or chemical change, no atoms are created or destroyed

Types of Pollutants

•Factors that determine the severity of a pollutant’s effects: chemical nature, concentration, and persistence.

Types of Pollutants

• Pollutants are classified based on their persistence: • Degradable pollutants – broken down – completely reduced

by natural processes

• Biodegradable pollutants – broken down by natural processes – usually bacteria

• Slowly degradable pollutants – takes decades or longer to degrade – DDT/plastics

• Nondegradable pollutants – will not break down naturally – toxic elements – Pb As Hg

Systems Respond to Change through Feedback Loops

• Positive feedback loop • Causes system to change further in the same direction

• Can cause major environmental problems

• Negative, or corrective, feedback loop • Causes system to change in opposite direction

Positive Feedback Loop

Fig. 2-18, p. 49

The Effects of Deforestation on the Loss of Water and Soil Nutrients

Fig. 2-1, p. 31

• This controlled field experiment measured the effects of deforestation on the loss of water and soil nutrients from a forest. V–notched dams were built at the bottoms of two forested valleys so that all water and nutrients flowing from each valley could be collected and measured for volume and mineral content. These measurements were recorded for the forested valley (left), which acted as the control site, and for the other valley, which acted as the experimental site (right). Then all the trees in the experimental valley were cut and, for 3 years, the flows of water and soil nutrients from both valleys were measured and compared.

Core Case Study: A Story About a Forest

• Hubbard Brook Experimental Forest in New Hampshire

• Compared the loss of water and nutrients from an uncut forest (control site) with one that had been stripped (experimental site)

• Stripped site:

• 30-40% more runoff

• More dissolved nutrients

• More soil erosion

Negative Feedback Loop

Fig. 2-19, p. 50

Lesson 3.2 Systems in Environmental Science

Positive feedback loops can help erosion turn a fertile field to desert in just a few years.

Dust storm, Stratford Texas, 1930s

Spheres of Function • Earth can be divided into spheres that are defined

according to their location and function.

Lesson 3.2 Systems in Environmental Science

Lesson 3.3 Earth’s Spheres

The movement of Earth’s plates has formed the deepest ocean trenches and the highest mountains.

The Geosphere

• Crust: Thin, cool, rocky outer “skin”

• Mantle: Very hot and mostly solid

• Core: Outer core is molten metal, inner core is solid metal


• Rocks and minerals on and below Earth’s surface:

Rock formation, Ouray National Wildlife Refuge, Utah

Plate Tectonics

• Crust and mantle are divided into: • Lithosphere: Crust and

uppermost mantle; divided into tectonic plates

• Asthenosphere: Soft middle mantle; heated by outer core

• Lower mantle: Solid rock

• Convection currents in the asthenosphere move tectonic plates.

• Collisions and separations of the plates result in landforms.


Volcano lava

Tectonic Plates

• There are three major types of plate boundary:

• Divergent

• Transform

• Convergent


Divergent and Transform Plate Boundaries

• Divergent boundaries:

Rising magma pushes

plates apart.

• Transform boundaries:

Plates slip and grind

alongside one another.


Divergent plate boundary

Transform plate boundary

Convergent Plate Boundaries

• Plates collide, causing one of two things to happen:

• Subduction: One plate slides beneath another.

• Mountain-building: Both plates are uplifted.


• Biosphere: The part of Earth in which living and

nonliving things interact

• Atmosphere: Contains the gases that organisms

need, such as oxygen; keeps Earth warm enough

to support life

The Biosphere and Atmosphere


Earth’s atmosphere, seen from space

The Hydrosphere

• Consists of Earth’s water

• Most of Earth’s water

(97.5%) is salt water.

• Only 0.5% of Earth’s water

is unfrozen fresh water

usable for drinking or

irrigation.

• Earth’s available fresh

water includes surface

water and ground water.


Did You Know? If it is depleted, groundwater

can take hundreds or even thousands of years to recharge completely.

Greenlaw Brook, Limestone, Maine

The Water Cycle


Lesson 3.4 Biogeochemical Cycles

A carbon atom in your body today may have been part of a blade of grass last year, or a dinosaur bone millions of years ago.

Fossilized bones in a

Colorado dig.

Nutrient Cycling

• Matter cycles through the environment.

• Matter can be transformed, but cannot be created or destroyed.

• Nutrients, matter that organisms require for life process, circulate throughout the environment in biogeochemical cycles.


Did You Know? Organisms require several

dozen nutrients, such as nitrogen, phosphorus, and carbon, to survive.

The Carbon Cycle


The Phosphorus Cycle


The Nitrogen Cycle


BELLRINGERS

• DRAW AN ATOM OF LITHIUM. PUT THE CORRECT NUMBER OF PROTONS AND NEUTRONS AND ELECTRONS IN THE ATOM.

• IDENTIFY EACH COMPOUND AS ORGANIC OR INORGANIC PUT A * NEXT TO ANY COMPOUND THAT ARE A HYDROCARBON

1. CH2N

2. C2H2O2

3. CO2

4. CH2O

5. CH4

6. CN

•NAME 3 HEAVY METAL ELEMENTS AND EXPLAIN WHY EVEN SMALL AMOUNTS CAN BE DANGEROUS.

•WHAT 6 ELEMENTS MAKE UP MORE THAN 98% OF ALL LIVING ORGANISMS?

•WHAT IS THE DIFFERENCE BETWEEN COVALENT AND IONIC BONDING?

r 3 earth’s environmental systems

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