Chapter - Kendall Hunt Publishing · Chapter 3: Earth System Science 41 Thickness of Earth’s crust is 0 to 70 kilometers (0 to 44 miles) Thickness of mantle is approximately 2,800

Chapter 3

39

In this chapter:

➢ Th e Earth System• Earth’s Lithosphere• Earth’s Hydrosphere• Earth’s Atmosphere• Earth’s Biopshere

➢ Climate Dynamics ➢ Past and Present Climates

“We travel together, passengers on a little spaceship, dependent upon its vulnerable reserves of air and soil, all committed for our safety to its security and peace; preserved from annihilation only by the care, the work, and, I will say, the love we give our fragile craft .”

— Adlai Stevenson, Former US Ambassador to the United Nations (1964)

Earth System Science

40 Introduction to Energy, Environment & Sustainability

The Earth System Fueled by the sun, our planet Earth travels through space and supports life, much like a spaceship. That perspective can be difficult to grasp, but it accurately describes the interconnected nature and vulnerability of Earth’s life-support systems. With continuous energy input from our sun and Earth’s geology, complex interactions among diverse, non-living systems originated and have evolved life (as we know it) on Earth for more than three billion years. Energy flows throughout Earth’s liv-ing and non-living systems determine their interactions and evolution throughout time. Earth’s living systems have intimately interacted with its non-living systems to sustain environmental conditions favorable for life on Earth. Within the past two centuries, human activities have made profound changes to living and non-living systems on Earth, affecting energy flows and disrupting long-term (>10,000 year) stability of environmental conditions (climate). Understanding these disruptions will help inform strategies to minimize the impact of human activities and adapt to abnormal environmental changes. However, we first need to learn how the Earth spaceship works, and if/how it can accommodate its most demanding passengers ever (humans).

Scientists frequently use the term Earth System to describe the complex, life-supporting interactions among Earth’s major living and non-living systems. Referred to as spheres to indicate their global extent, four (4) major system com-ponents interact in intricate ways to produce the environmental conditions found throughout Earth. Table 3.1 describes Earth’s four major system components, pre-sented in approximate order of their evolution.

Interactions among Earth’s major systems and their subsystems happen at drasti-cally variable time scales (seconds, days, centuries, millions of years) and distance scales (microscopic, local, regional, global). Meteorological metrics, e.g., tempera-ture, atmospheric pressure, cloud cover, sun position, precipitation, air-quality, etc. over a period of time are often used to describe the environmental conditions of a region. Changes in environmental conditions on an hour-to-hour, or day-to-day basis describe the region’s weather. If we consider average weather over seasons,

Earth SystemInterconnected system comprised of lithosphere, hydrosphere, atmosphere and biosphere which maintains favorable conditions for life

WeatherShort-term meteorological conditions in an area

Table 3.1 Earth’s Major Systems and Descriptions

Earth’s System Component Description

Lithosphere Earth’s crust covering its core (both ocean floor and all continents)

Hydrosphere Earth’s water in all forms (solid/liquid/vapor)

Atmosphere Thin layer of gas (air) covering Earth’s surface

Biosphere Life on Earth in all its variable forms

Chapter 3: Earth System Science 41

Thickness of Earth’scrust is 0 to 70 kilometers(0 to 44 miles)

Thickness of mantle is approximately2,800 kilometers (1,740 miles)

Thickness of lower mantle isapproximately 2,100 kilometers(1,300 miles)

Thickness of core isapproximately 3,500kilometers (2,175 miles)

Distance from Earth’ssurface to center isapproximately 6,370kilometers (3,960 miles)

Outer core

Innercore

Lowermantle

Uppermantle

Crust

Figure 3.1 Cross Section Schematic of Earth.

years, decades, or centuries we can describe the region’s climate. Weather and cli-mate are distinct and different—they measure the same things, but over drastically different time scales. Weather influences our choice of clothing, e.g., swimming suit or parka, whereas climate influences our choice of crops, e.g., tropical fruits or potatoes. Climate conditions also affect how living systems evolve and migrate. Al-though occurring at different time scales, both climate and weather are products of complex interactions among Earth’s four major system components. We now review these systems in approximate order of their evolution on Earth. (Table 3.1).

Earth’s LithosphereAbout four and a half billion years (4.5 × 109 years) ago, planet Earth formed dur-ing a process known as accretion, essentially gravity pulling together adjacent mass (from within our solar system) into the enormous molten mass that was the hot young Earth. After about a billion years passed and Earth cooled, it formed into a spherical shape with distinctive layers, as shown in Figure 3.1. Earth’s inner core is a hot and dense iron- and nickel-based solid sphere, held in shape by extreme pres-sure from the flowing liquid iron and sulfur core surrounding it. The movement of the iron (a magnetic material) in Earth’s core creates a convective dynamo, which generates a protective magnetic field, extending far beyond Earth’s atmosphere and shielding Earth’s surface (and life on it) from deadly radiation from the sun and elsewhere in space. Above Earth’s core are the two mantles, which are flowing layers of various molten (some radioactive) metals and their oxides, sulfides, and salts.

ClimateLong-term measurement of meteorological conditions of an area

AccretionGravitational collection of inter-stellar masses into planets and other orbiting bodies

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During the cooling process, Earth’s outermost layer formed into a thin rocky crust—its relative thickness like that of tinfoil covering a basketball. As the crust formed over Earth, it separated into about a dozen individual pieces, called tectonic plates. The plates continue to form and push into and under one another, building continents and mountains and powering earthquakes, geysers, and volcanoes, as illustrated in Figure 3.2. These tectonic processes created the Earth’s surface to-pology (ocean floors, continents, mountains, ridges, valleys, etc.) and also ejected tremendous amounts of volatile gases and vapors above the crust, spawning the early atmosphere. Earth’s rocky crust, or lithosphere, contains many raw materi-als (metals, minerals, fossil fuels, etc.) that we use to support and power modern civilization.

Earth’s HydrosphereWater (H2O) is a unique chemical compound, and is often considered the universal solvent. Water is almost everywhere on and near Earth’s surface, it will dissolve everything over time, and its liquid form supports life (as we know it). Like many materials, water can exist in solid, liquid and gas forms, depending on environmen-tal conditions, such as temperature and pressure (ice, snow, rain, vapor or steam). The origins of water (and many other elements and compounds) on Earth are not entirely clear, but many scientists agree that it was likely a combination of “out-gassing” volatile compounds from the molten mantle, in addition to deposition from asteroids, and various chemical processes interacting with radiation from the sun. Soon after the Earth cooled, formed its crust, and developed a primitive

Tectonic PlatesLarge sections of Earth’s lithosphere that slowly generate and collide at their boundaries

Seafloor spreading

Continental meets oceanic

Oceanic meets oceanic

Continental meets continental

Figure 3.2 Plate Tectonics on Earth. R

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atmosphere, temperature and pressure conditions were favorable to form liquid water and Earth’s primordial oceans, which covered all but a few volcanic islands (before tectonic plate activity formed the continents).

As continents formed, and Earth’s surface topology began taking shape, the mod-ern version of the water cycle began, which transported water in its various forms throughout the continuously evolving lithosphere, atmosphere, and emerging bio-sphere. Illustrated in Figure 3.3, Earth’s water cycle is driven by heat (thermal and radiant energy) from the sun, which vaporizes water from its liquid and solid forms through evaporation, transpiration, and respiration processes. The water is then transported into and throughout the atmosphere in the form of invisible vapor and denser clouds. As the clouds cool, rain or snow forms and falls to the ground, where it builds up, melts or pools, and is transported down to the oceans via surface or underground routes. The water cycle is one example of a biogeochemical cycle—one of many life-supporting cycles within the Earth System.

Earth’s AtmosphereEarth’s atmosphere evolved through complex interactions with its lithosphere, (ejecting volatile compounds from volcanoes), hydrosphere (gasses dissolving in oceans or water vapor in air), and biosphere (respiration from plants and ani-mals). Earth’s atmosphere effectively functions to filter out ultraviolet (UV) radia-tion from the sun and maintain surface temperatures on Earth favorable for liquid water (on average). Earth’s present day atmosphere consists of several layers, as illustrated in Figure 3.4, which also defines the boundaries between these layers. While each layer has its own distinct composition and function, the two nearest

Biogeochemical CycleInterconnected cycle within the Earth System involving biosphere, lithosphere, hydrosphere and atmosphere

Figure 3.3 The Water Cycle on Earth.So

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layers, comprising over 90% of the atmosphere’s mass, are the strato-sphere and lower troposphere, which is the air we live in. Like the very outer skin on an onion, the layered atmosphere forms an extremely thin covering over Earth’s surface.

The pressure of the atmosphere is equivalent to the average amount of force the atmosphere exerts against a given area. At sea-level on Earth, the air pressure is about 1 atmosphere (1 atm = 14.7 pounds per square inch, or psi), a common unit for measuring pressure. As we climb above sea level, the air pressure decreases substantially. At about 3.4 miles above sea level (~18,000 ft. or ~5,500 m.), the pressure is about half its value at sea level, or about 0.5 atm. Going approximately 3.4 miles fur-ther up to ~6.8 miles above sea level where commercial airliners cruse (~36,000 ft. or ~11,000 m.), the pressure is again halved, to about 0.25 atm. This approximate elevation also forms the boundary between the troposphere and stratosphere. The stratosphere then continues upwards for more than 30 miles (158,400 ft. or 48,280 m.), before reaching the wispy outer atmosphere layers (mesosphere, thermosphere and exo-sphere) interfacing with outer space.

Figure 3.5 illustrates the gradients of temperature within the atmospheric layers. Like pressure, temperatures also change dramatically within tropo-sphere and stratosphere, however, they do not continually decrease with

Figure 3.4 Schematic of Earth’s Atmospheric Layers with Boundary Layers Defined.

Figure 3.5 Temperature Profile in Earth’s Atmosphere.

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GHG Emissions

Reflected Solar Energy

Energy Absorbed

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Radiation from surface into space

Incoming Solar Energy

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elevation. At the surface (near sea level), on average, the Earth’s temperature is about 15°C (~60°F). As we climb above sea level, the temperature drops. Where commercial airliners fly, the temperatures are a frigid -40°C. Temperatures remain low and stable as we climb higher into the interface with the stratosphere before increasing again within the stratosphere. This is an important observation in understanding Earth’s atmosphere and climate. The troposphere effectively traps higher temperatures close to the Earth’s surface, making liquid water (and physical conditions for life) favorable.

Two of the functions of Earth’s atmosphere are to block UV radiation and maintain favorable surface temperatures. The first function is primarily provided by a thin layer of ozone (O3) gas within the stratosphere, which absorbs UV radiation before it gets to the Earth’s surface, protecting life against genetic damage. The second function occurs in the troposphere, where a small fraction (<4%) of the gases in the air trap heat by absorbing infrared (IR) radiation, which is re-radiating from Earth after it is warmed by the sun. This process, known as the greenhouse effect is illus-trated in Figure 3.6, and it plays a critical role in Earth’s climate dynamics. Carbon dioxide (CO2) is a major greenhouse gas, and its concentration substantially regu-lates the average surface temperature on Earth, which governs the amount of water vapor in the troposphere (another strong, but more transient greenhouse gas). Wa-ter vapor only lasts a few days in the atmosphere before returning to the terrestrial water cycle, whereas carbon dioxide can remain in the atmosphere for centuries.

Earth’s BiosphereSimple forms of life on Earth are thought to have first developed soon after the oceans formed over three billion years ago. One model speculates that volatile gases from volcanoes, combining with energy from lighting formed basic organic chemi-cals, which, when dissolved in water, react to form basic amino acids—the building

Greenhouse EffectEffect of retaining radiation within a system, similar to transparent walls of greenhouses


blocks of life. From its rudimentary form of single-cell species of archae and eu-bacteria, life evolved slowly over billions of years into five distinctive kingdoms, as shown in Figure 3.7. These kingdoms (plants, animals, fungi, protist, and bacteria) differ in the way they process energy within their environments. Within each of the kingdoms, life is further classified into phylum, class, order, family, genus, and finally species, all related to the ecological niche and genetic code that define them. Simple bacteria can parasitically use the energy within a human or other animal host to survive. These microscopic bacteria species interact with the host animal’s sub-systems in symbiotic ways to promote the health of the animal, and therefore the bacteria’s environment. Symbiotic relationships form the foundation for very successful living systems. In fact, human bodies have more bacterial cells than hu-man cells (by orders of magnitude). These bacterial cells help humans in everything from digestion to breast feeding.

SymbioticRelationship among living organisms with mutual benefits

Protoctista(Protista)

Bacteria(Monera,Prokaryotae)

Plantae

Fungi

Animalia

Eukarya(Eukaryotes)

Anthophyta(flowering plants)

Coniferophyta(conifers)

Ginkgophyta(ginkgo)

Filicinophyta(ferns)

Sphenophyta(horsetails)

Cycadophyta(cycads)

Lycophyta(club mosses)

Bryophyta(mosses)

Hepatophyta(liverworts)

Anthocerophyta(hornworts)

Basidiomycota(club fungi)

Ascomycota(sac fungi)

Zygomycota(conjugating fungi)

Craniata(vertebrates)

Mollusca(molluscs)

Hermichordata(acorn worms)

Crustacea(crustaceans)

Annelida(segmented

worms)

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(insects)

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(jellies)

Rotifera(rotifers)

Platyhelminthes(flatworms)

Porifera(sponges)

Chlorophyta(uni– and multicellular

green algae)

Phaeophyta(multicellularbrown algae)

Rhodophyta(multicellular

red algae)

Diatoms

Oomycota(water molds)

Rhizopoda(sarcodines)

Actinopoda(heliozoans)

Discomitochondria(flagellates)

Myxomycota(slime molds) Dinomastigota

(dinoflagllates)

Ciliophora(ciliates)

Apicomplexa(sporozoans)

Cyanobacteria

EndosporaActinobacteria

Gram-positiveBacteria

greennonsulfurbacteria

Gram-negative Bacteria

purplebacteria

mycoplasmas

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methanogens

halophiles

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Archaea

Deinococci

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Eubacteria

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Plants form a basic foundation for more complex life through a process known as photosynthesis. Using direct solar energy, photosynthetic species convert carbon dioxide (CO2) and water (H2O) into oxygen (O2) and basic carbohydrate (CH2O), as shown in Equation 3.1.

PhotosynthesisProcess of converting Radiant Energy into Chemical Energy


CO2 + H2O + Energy = CH2O + O2

Equation 3.1

A simplified representation of the process is illustrated in Figure 3.8. Carbohydrate molecules, such as sugars, form the basic building blocks for biomass, and through various energy-converting biological processes (governed by genetic codes), car-bohydrates are used in the transformation and synthesis of numerous complex biochemicals that comprise life on Earth. Since photosynthesis consumes carbon dioxide and emits oxygen, it also changes the Earth’s atmospheric composition.

Bacteria (monera) and algae (protista) coexist with animals, plants, and fungi in complex communities that have co-evolved throughout time. These living commu-nities interact with all Earth system components in extremely diverse and complex ecosystems. In concert with non-living systems, ecosystems provide various services in terms of basic food production and waste absorption for its inhabitants. Ecosystem services are a very important feature in Earth’s climate system and human society.

Over millions of years, ecosystems evolved diverse and complex energy flows in the form of food webs, with trophic levels describing where species within the com-munity rank in the energy flow. A generic North-American ecosystem is presented in Figure 3.9. The trophic levels include the producers (all photosynthetic species on land or in sea), the primary consumers (small animals, birds, and fish eating the producers), the secondary and tertiary consumers (larger animals, birds, and fish that eat smaller ones and the producers), and the decomposers, or micro-consumers (fungi and bacteria that eat the dead producers and consumers and produce nutri-ents for the producers). The number and complexity of different interacting spe-cies in ecosystems is called biodiversity, which also provides a metric to assess the health and resilience of ecosystems.

Ecosystems can have numerous levels of consumers; however, the effective energy transfer efficiency between each trophic level is only about 10% (from the original

EcosystemCommunity of evolving living and nonliving components linked together by energy flows

Trophic LevelsFood chain levels within an ecosystem

BiodiversityMeasurement of quantity and diversity of living species within ecosystem

Figure 3.8 Basics of Photosynthesis.

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conversion of solar energy in producers), which limits the number of levels. For ex-ample, if the tertiary consumers only eat the secondary consumers, they are living from only 0.1% of the ecosystem’s original solar energy input (that was converted into biomass by photosynthesis, which is itself only ~5% efficient). From 100% of the solar energy converted into biomass by the producers, the energy conversion efficiency to primary consumers is about 10%, that of the conversion from primary to secondary consumers is about 10%, and the final conversion to tertiary con-sumers is about 10% (100% × 10% × 10% × 10% ∙ 0.1%). Depending upon the long-term climate conditions, incredibly diverse ecosystems have evolved in differ-ent regions and at different rates on Earth for over three billion years. Millions, if not billions, of living species have come and gone throughout this time, constantly evolving to adapt to environmental conditions and carry out life’s basics; survival, procreation, and endurance.

Earth’s climate is a product of complex interactions among its major systems and subsystems. Throughout Earth’s climate history, changes have been happening as a result of various internal and external forcing factors and responses through interacting components. An illustration of this process is provided in Figure 3.10. Historically (before humans), three (3) primary forcing factors have acted upon Earth’s climate. These are changes in:

1) plate tectonics;

2) Earth’s orbit; and,

3) solar intensity.

Each of these forcing factors can have significant impact on the interactions within the Earth System. Plate tectonics shift continents, build mountains, and spawn vol-canoes, all of which change the climate. Changes in Earth’s orbit bring it closer and

Forcing FactorsChanges in Earth’s system, which produce changes in global climate

Climate Dynamics

Figure 3.9 Trophic Levels in an Ecosystem.

Heat

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further from the sun, thus changing solar energy inputs. And, changes in the sun’s intensity have a direct relationship with changes in Earth’s climate. All of these changes affect the energy flows within the Earth System at different time scales, and directly influence both short and long-term environmental conditions (weather and climate).

When these climate forcing factors change, Earth’s four major systems react and interact, resulting in fast or slow responses. The continuous energy from the sun drives various life-supporting biogeochemical cycles on Earth, such as the water cy-cle presented in Figure 3.3, and the carbon cycle, which is illustrated in Figure 3.11.

Figure 3.10 Climate Dynamics, Forcing Factors, System Interactions and Responses.

Figure 3.11 Global Carbon Cycle.

Changes in plate tectonics

Changes in Earth’s orbit

Changes in Sun’s strength

CLIMATE FORCING FACTORS

CLIMATE SYSTEM(internal interactions)

CLIMATE VARIATIONS(internal responses)

Atmosphere

Atmosphere

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HydrosphereBiosphere

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The carbon cycle largely governs global surface temperatures by heat trapping gases (like carbon dioxide) in the atmosphere, through the greenhouse effect (Figure 3.6). The carbon on the Earth’s surface is delivered to the atmosphere via respiration, de-composition, exchange with carbon dissolved in the oceans and the combustion of fuels. The carbon is removed from the atmosphere by photosynthesis on land and in the oceans (forming biomass) as well dissolving into the oceans and the combustion of fuels. The carbon is stored for longer time periods (millions of years) in the deep ocean and in fossil fuels (ancient sunlight). Overall, human activities are adding an additional 9–10 gigatons (9–10,000 million tons) of carbon to the atmosphere each year. About half of the additional carbon emitted by humans into the atmosphere is absorbed by biomass and the oceans, with the remainder accumulating in the atmosphere (4–5 gigatons per year). Beyond water and carbon, other important biogeochemical cycles include those involving nitrogen, oxygen, phosphorous, and sulfur. In the past two centuries, human activities have also had a significant impact on each of these cycles.

Earth System science focuses on how Earth’s major systems interact to produce envi-ronmental conditions favorable for life. Legendary British scientist, James Lovelock, described this interaction as a feed-back between life (biology) and its physical and chemical components, such that physical and chemical conditions were maintained to sustain life on Earth. He hypothesized that the Earth is itself a sort of super-organism that maintains an environment favorable for life by balancing complex biogeochemical processes and cycles. The super-organism was named Gaia after the Greek goddess of the Earth. Dr. Lovelock defined Gaia as, “a complex entity involv-ing the Earth’s biosphere, atmosphere, oceans, and soil; the totality constituting a feedback system which seeks an optimal physical and chemical environment for life on this planet.”

It is important to appreciate the complex interactions within the Earth System, and how these sustain life as we know it. As our understanding of past global climate changes improves through increasingly available data, global climate models are being developed to describe how various forcing factors affect internal system interactions, and compare these with past climate records. The better refined the global climate models in describing past changes, the better we will be in predicting changes in the future. Next, we explore climates of the ancient past and until today.

Forcing factors on Earth’s climate change over time, and Earth’s major systems (lithosphere, atmosphere, biosphere, and hydrosphere) interact in complex ways, which in turn creates changes within Earth’s climate, and therefore in each of the spheres (Figure 3.10). This continual forcing, feedback, and response has occurred throughout Earth’s four billion years, resulting in dramatic changes in global cli-mate. Since geological time is so immense, we break down Earth’s history into eons, which are divided into eras, which are then further divided into periods, epochs,

Past and Present Climates


and ages. Difficult to describe using conventional linear graphics, the magnitude of geological time and major events in the biosphere are often presented using succes-sive linear scaled and spiraling time graphics, such as that presented in Figure 3.12. Look closely at these graphics to get a feel for how little time humans have existed—the Holocene Epoch marked the beginning of the Agricultural Revolution. In fact, if we were to compress all time since the beginning of the universe, with the Big Bang on January 1, the Earth would have only formed by about mid-September, the first mammals evolved about December 26, and all of human history occurred during the last half hour of New Year’s Eve.

As evidence of the interaction of Earth’s system components, major changes in the biosphere, hydrosphere, and lithosphere during Earth’s history have generated significant changes in the composition of the atmosphere and lithosphere. In the early part of Earth, carbon dioxide (CO2) comprised as much as 30% of Earth’s atmosphere by volume. The process known as chemical weathering dissolves the carbon dioxide (CO2) in water (H2O) making carbonic acid (H2CO3), which is used by ocean organisms to grow shells of calcium carbonate (CaCO3), and ultimately forms limestone rock. As plants grew, they too consumed the carbon dioxide in the atmosphere and emitted oxygen (through photosynthesis), which now com-prises about 20% of our atmosphere (carbon dioxide is currently less than 1%). The current atmosphere on Earth now has the following approximate composition (by

Chemical WeatheringGeological process which changes rock composition, often incorporating atmospheric carbon dioxide into solid carbonates, e.g., limestone

Figure 3.12 Geologic History of Earth.R

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volume): 78% nitrogen (N2); 20% oxygen (O2); 1% argon (Ar); 0–3% water vapor (H2O); 0.04% carbon dioxide (CO2); and, other trace gases and vapors.

It is informative to analyze past climates in terms of average surface temperature, which in large part dictates the operation of the global climate system. This in-formation is often provided to us by isotope ratios within cores, drilled out from sediments or glacial ice to preserve the layering in which it was deposited through successive sedimentation or precipitation (snow) cycles (older layers on bottom, younger layers on top). The isotope ratio between oxygen-18 and oxygen-16 (18O/16O) within the ice provides us with proxy data for the surface temperature in which the ratio was created when it formed into snow. Oxygen-18 (18O) is a heavier isotope than oxygen-16 (16O), the most abundant form of oxygen. Simply stated, water molecules with 18O (H2

18O) require more energy to vaporize than that with 16O (H2

16O), so when temperatures are warmer, higher 18O/16O ratios are measured. A similar process occurs between deuterium (2H) and protium (1H), both isotopes of hydrogen. Isotope ratio data has been collected to describe average surface temperatures on Earth throughout the past 800,000 years or so. Figure 3.13 shows proxy temperature data from deuterium isotope ratios, as well as CO2 concen-trations from ice cores taken at Lake Vostok in Antarctica. CO2 concentrations (measured in air bubbles trapped in the ice) are correlated with average surface temperatures throughout this time, indicating the strong connection (correlation) between the Earth’s average surface temperature, and its CO2 concentration.

IsotopeAtom with more or less neutrons compared to most stable atom

300

50

–5–10

Carbon Dioxide (parts per million)

Antarctic Temperature (°C)

Data (Years Before Present)

250

200

800,000

800,000

600,000

600,000

400,000

400,000

200,000

200,000 0

0Figure 3.13 Temperature change relative to 1900 (dark lines) and CO2 concentrations (lighter lines) for past 800,000 years. So

urce

: NA

SA.


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Homework/Quiz(Open Book—Write Answers Below Questions—Show All Work)

Quiz

Write Answers in Spaces and Show All Work:

1. In your own words, describe the four (4) basic components of Earth’s climate.

2. What are the three (3) major (non-human) climate forcing factors?

3. In your own words, describe the difference between weather and climate.

4. Describe the order in terms of height above the Earth: the stratosphere, the lithosphere and the troposphere.

5. In your own words, describe how surface temperatures on Earth are maintained.


Problems

Write Answers in Spaces and Show All Work:

1. In the table below, describe processes in which Earth System Component #1 interacts with Earth System Component #2:

2. In your own words, describe the basic chemistry of photosynthesis.

3. Sketch and describe a simplified example of a local ecosystem in terms of life forms and energy exchanges.

Earth’s System Component #1 Earth’s System Component #2 Example Interactions

Lithosphere

Biosphere

Atmosphere

Hydrosphere

Biosphere

Lithosphere

Atmosphere

Hydrosphere

Atmosphere

Lithosphere

Biosphere

Hydrosphere

Hydrosphere

Lithosphere

Biosphere

Atmosphere

Documents

Chapter - Kendall Hunt Publishing · Chapter 3: Earth System Science 41 Thickness of Earth’s crust is 0 to 70 kilometers (0 to 44 miles) Thickness of mantle is approximately 2,800