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ENVSCI 101 The Global Environment Spring, 2022

Exercise 3 40 points YOUR NAME ____________________


DATE March 10 2022

DUE DATE March 22, 2022


Please answer all of the questions to the best of your ability. Use the textbook, lecture slides, and the internet as your reference guide.

Part 1: Vocabulary

Use once or two sentences to define the following term. You can use your textbook or the internet as a source.

Mineral =

Lithosphere =

Sedimentary Rock =

Metamorphic Rock =

Igneous Rock =

Magma =

Lava =

Convergent Margin =

Divergent Margin =

Transform Margin =

Subduction =

Pangaea =


Depletion time=

Geologic time=

Part 2: General Questions

1. What properties must a substance have to be considered a mineral?

2. Draw a diagram of the structure of the Earth. Be sure to include the inner core, outer core, mantle, asthenosphere, and crust.

3. Describe the Rock Cycle. A diagram can be used in addition to your description. Be sure to include the 3 major types of rocks.

4. What is the driving force behind the Earth’s plates moving? Draw a diagram of this process including the asthenosphere, crustal plates, and convective cells.

5. Draw a diagram of the three types of convergent boundaries (ocean-ocean, ocean-continent, continent-continent). Be sure to include the landscape feature(s) associated with each (i.e. mountains, volcanoes, trenches, island arc chains). Also provide a real world example of where each occurs.

Page 1 of 9


Lecture 8

More Than Half of the World’s People Live in Urban

” Urbanization
” Creation and growth of urban and suburban

? 55% of people live in such areas

” Urban growth
” Rate of increase of urban populations
” Immigration from rural areas

” Pushed from rural areas to urban areas

” Pulled to urban areas from rural areas

Three Major Urban Trends

” Three major trends
” Proportion of global population living in urban areas is


” Number and sizes of urban areas are increasing
” Megacities: more than 10 million residents

” Hypercities: more than 20 million residents

” Poverty is becoming increasingly urbanized
” Mostly in less-developed countries

Three Major Urban Trends

Urbanization in the United States

” Three phases between 1800 and 2015

” Migration from rural areas to large
central cities

” Migration from large central cities to
suburbs and smaller cities

” Migration from North and East to South
and West

” Aging infrastructure

” Deteriorating services

Urban Sprawl

” Urban sprawl

” Low-density development on the
edges of cities and towns

” Contributing factors to U.S. urban sprawl

” Abundant, affordable land

” Automobiles

” Federal and state funding of highways

” Inadequate urban planning

Urban Sprawl

” Suburban sprawl destroys forests, wetlands,
and cropland

” Forces people to drive almost

” Contributed to economic deaths of many
central cities

Urbanization Has Advantages

” Cities
” Centers of economic development,

innovation, education, technological
advances, social and cultural diversity,
and jobs

” Better medical care than rural areas
” Recycling economically feasible
” Reduce stress on wildlife habitats
” Mass transportation typically available

Urbanization Has Disadvantages

” Large ecological footprints
”Consume 75% of the world’s resources

” Lack of vegetation
” Water problems

”Runoff, flooding, wetland degradation
” Pollution and health problems

”Air and water pollution
”Solid and hazardous wastes

Urbanization Has Disadvantages

” Excessive noise
” Noise pollution impairs or interferes with

hearing, and causes stress and accidents

” Local climate effects and light pollution
” Cities tend to be warmer, rainier, foggier, and

cloudier than rural areas
” Urban heat island
” Artificial light has affected some species

(disorientation, natural behavior, higher
predation levels, disrupts light sensitive cycles,
higher mortality rates).

Poverty and Urban Living

” Slums
” Areas dominated by dilapidated housing
” Squatter settlements and shantytowns
? Scavenged materials, on unoccupied land

without the owner’s permission

” Terrible living conditions
? Lack basic water and sanitation
? High levels of pollution

Cities Can Grow Outward
or Upward

” Compact cities
” Hong Kong, China

” Tokyo, Japan

” Mass transit

” Dispersed cities
” The United States and Canada

” Car-centered cities

Pros and Cons of Motor Vehicles

” Advantages
” Mobility and convenience

” Provides jobs

” Production and repair of vehicles

” Supplying fuel

” Building roads

Pros and Cons of Motor Vehicles

” Disadvantages
” Accidents kill 1.25 million people per

year globally and injure another 50

” Kill 50 million wild animals and
pets per year

” Largest source of outdoor air pollution

” Helped create urban sprawl and car
commuter culture

” Traffic congestion

Reducing Automobile Use

” Full-cost pricing–environmental gas tax
” Consumer education

” Funds for mass transit and bike lanes

” Opposition from car owners and industry

” Raise parking fees

” Charge tolls on roads, tunnels, and

” Car-sharing networks

Alternatives to Cars

” Foot power
” Bicycles
” Buses
” Heavy-rail systems

” Subways, elevated rail, and metro trains

” Light-rail systems
” Streetcars, trolleys, and tramways

” Rapid-rail system between urban areas

Conventional Land-Use Planning

” Land-use planning
”Governments control uses of certain parcels of land by legal and

economic methods
” Zoning

”Land designated for certain uses
”Mixed-use zoning

Smart Growth

” Set of policies and tools that encourage
environmentally sustainable development

” Uses zoning laws to channel growth and
reduce ecological footprint

” Reduces dependence on cars
” Discourages sprawl
” Many European countries

” High taxes on heating fuel and gasoline
encourages compact cities

Preserving and
Using Open Space
” Urban growth boundary

” U.S. states: Washington, Oregon, and

” Greenbelts
” Canadian cities: Vancouver and


” Western European cities

” Municipal parks
” U.S. cities: New York City and San


New Urbanism

” Conventional housing development
” Rows of houses on standard-size lots

” Cluster development
” Mixed housing types and green space

” New urbanism: environmental
” Walkable, bike friendly neighborhoods
” Mixed use and diversity
” Quality urban design; smart transportation
” Sense of community

The Eco-City Concept: Cities for People, Not Cars

” Eco-city (or green city)
” New model for urban development

” People-oriented, not car-oriented

” Walk, bike, or use mass transit

” High percentage of MSW reused, recycled, or

” Tree planting

” Vertical farms

” Environmental justice

The Eco-City Concept in Curitiba, Brazil

” Ecological capital of Brazil

” Superb bus rapid-transit system
” 85% of the city’s commuters

” Streams and parks

” Recycling programs

” Care for the poor

” High literacy rate

” Population increased fivefold since


” 50–150 people come together to design and
live in more ecologically, economically, and
socially sustainable villages in rural and
suburban areas
” Solar and wind power

” Energy-efficient housing

” Organic farming

” 2014: more than 400 eco-villages in over 70

  • Urbanization
  • More Than Half of the World’s People Live in Urban Areas
  • Three Major Urban Trends
  • Three Major Urban Trends
  • Urbanization in the United States
  • Urban Sprawl
  • Urban Sprawl
  • Urbanization Has Advantages
  • Urbanization Has Disadvantages
  • Urbanization Has Disadvantages
  • Poverty and Urban Living
  • Cities Can Grow Outward? or Upward
  • Pros and Cons of Motor Vehicles
  • Pros and Cons of Motor Vehicles
  • Reducing Automobile Use
  • Alternatives to Cars
  • Conventional Land-Use Planning
  • Smart Growth
  • Preserving and Using Open Space
  • New Urbanism
  • The Eco-City Concept: Cities for People, Not Cars
  • The Eco-City Concept in Curitiba, Brazil
  • Eco-Villages

Food Resources

Why Is Good Nutrition Important?

• Many people in less-developed countries have
health problems from not getting enough food

• One in 8 people are not getting enough food (800
million people)

• Many people in more-developed countries suffer
health problems from eating too much

• Greatest obstacles to providing enough food for

• Poverty, war, bad weather, and climate change

Chronic Hunger and Malnutrition
To maintain good health, people need:

• Macronutrients
• Carbohydrates
• Proteins
• Fats

• Micronutrients
• Vitamins

• Examples: A, B, C, and E
• Minerals

• Examples: Iron, iodine, and calcium

Many People Suffer from Lasting Hunger and

Low-income, less-developed people suffer from:

• Chronic undernutrition:
• Not enough food to meet basic energy needs

• Chronic malnutrition:
• Not enough protein or other key nutrients (eat mostly low

on the food chain – wheat, rice, and corn)

• Famine:
• Severe shortage of food

• Crop failures due to drought, flooding, or war

• Can cause mass starvation, many deaths, economic chaos,
and social disruption

Essential Micronutrients
• Two billion people deficient in one or more vitamins

and minerals

• Too little iron
• Causes anemia (fatigue and increased chance of infection)

• Iodine
• Essential for thyroid function
• Chronic lack causes stunted growth, mental retardation,

and goiter
• Irreversible brain damage

Health problems from eating too much food
People live in food deserts where diet is heavy in cheap
food filled with sugar and fats

• Overnutrition:
• Excess body fat from too many calories and too little


• Similar health problems to those who are underfed:
• Lower life expectancy

• Greater susceptibility to disease and illness

• Lower productivity and life quality

Poverty Is the Root Cause of Hunger and

• 28% of world’s people struggle to survive on
USD $3.10 per day

• Poverty prevents daily access to nutritious food

• Other obstacles to food security:
• War

• Corruption

• Bad weather

• Climate change

Poverty Is the Root Cause of Hunger and

• Generally, the number and percentage of people
suffering from chronic hunger has declined
since 1992

• Some continents, like Africa, still suffering

Food Production has Increased Dramatically

• Three systems produce most of our food:
• Croplands produce grains

• Primarily rice, wheat, and corn
• At least half the world’s people survive primarily by eating

three grain crops–rice, wheat, and corn–because they cannot
afford meat

• Rangelands, pastures, and feedlots produce meat and meat

• Fisheries and aquaculture provide fish products

• Important technological advances have increased food production:
• Irrigation, synthetic fertilizers, and pesticides

Industrialized Agriculture
• Industrialized agriculture (high input):

• Heavy equipment
• Large amounts of financial capital, fossil fuels, water, inorganic

fertilizers, and pesticides
• Single crop
• Major goal: Steadily increase crop yield
• Produces 80% of world’s food

• Plantation agriculture–cash crops (form of industrialized

• Primarily in less-developed countries
• Bananas, coffee, soybeans, sugarcane, palm oil and vegetables
• Mostly for export to other countries

Traditional Agriculture
• Traditional agriculture provides about 20% of the world’s agriculture

• Traditional subsistence agriculture:
• Human labor and draft animals for family food
• Little leftover or for sale

• Traditional intensive agriculture:
• Higher yields through increased labor, animal manure, and

• May have some leftover for sale

• Polyculture:
• Several crops grown on same farm
• Benefits over monoculture


• One type of polyculture–slash and burn

• Burning and clearing small plots of land, growing
multiple types of crops until soil is depleted of
nutrients, and then shifting to other plots to start the
process again

Increasing Influence of Organic Agriculture
• Crops grown without synthetic pesticides or fertilizers:

• No genetically engineered seed varieties

• Animals must be raised with 100% organic feed without
antibiotics or growth hormones

• More labor-intensive than conventionally produced

• Costs more

Impacts of Green Revolution
• Farmers have two ways to get more food–farming more land or getting higher yields

• Green Revolution–using high input industrialized agriculture to increase crop yields (1950-

• Develop and plant monocultures of high-yield key crops
• Rice, wheat, and corn

• Use large amounts of fertilizers, pesticides, and water
• Use multiple cropping

• Second Green Revolution (1967)
• Fast growing varieties of rice and wheat were introduced to India, China, and Brazil

• World grain production quadrupled between 1950 and 2018

• https://www.youtube.com/watch?v=ymMajMVCFhk

Crossbreeding and Genetic Engineering
• Scientists have used crossbreeding to produce new varieties of food

• First gene revolution:
• Crossbreeding through artificial selection

• Slow process (15 years or more to create a new product)
• Amazing results (ears of corn used to be size of your finger)

• Genetic engineering–second gene revolution:
• Alter an organism’s DNA
• Genetically modified organisms (GMOs)–transgenic organisms
• Altering organisms to produce better products

Growing Meat Consumption

• Meat production increased more than six folds between 1950
and 2018:

• Pork, poultry, and beef top products

• Increased demand for grain
• Greater reliance on grain imports

• China

• About half of the world’s meat raised on rangeland:
• Half in factory farm system

Fish and Shellfish Production
• Fishery:

• World’s third major producing food system

• Concentration of a particular species suitable for
commercial harvesting

• 29% are overfished

• 61% harvested at full capacity


• Aquaculture:
• Fish farming

• Amount of fish and shellfish produced globally
through aquaculture increased 21% from 2000 to 2016

• Wild catch leveled off and declined

• Farming of meat-eating species growing rapidly
• Fed fish meal or fish oil produced from other fish and

their waste

Energy Inputs in Industrialized Food Production
• Mostly use nonrenewable energy for food production:

• Oil and natural gas

• Ten units of fossil fuel energy used for every unit of food energy in the U.S.:
• Amount of energy per calorie used to produce crops in the U.S. has declined 50%

since the 1970s
• Less energy required to produce nitrogen fertilizer

• Rising use of conservation tillage (reduces harmful effects of plowing)

Environmental Effects of Industrialized Food
• Factors that may limit future food production:

• Soil erosion and degradation

• Desertification

• Irrigation water shortages

• Air and water pollution

• Climate change

• Loss of biodiversity

Producing Food Has Major Environmental Impacts
• Industrialized agriculture has harmful environmental impacts:

• Uses about 70% of freshwater removed from aquifers and surface waters worldwide

• Emits 25% of the world’s greenhouse gas emissions

• Produces 60% of all water pollution

• Some say industrialized agriculture is unsustainable

Topsoil Erosion
• Topsoil has several necessary nutrients and provides vital ecosystem


• Need healthy soils for agriculture

• Soil erosion:
• Movement of soil by wind and water
• Natural causes
• Human causes (agriculture)

• Three major harmful effects of soil erosion:
• Loss of soil fertility
• Water pollution
• Release of carbon stored in the soil as CO2

The Phosphate Crisis
• Phosphate is needed for fertilizer

• Availability from mines is limited

• Potential solutions
• Water crops with phosphate-rich wastewater
• Reduce soil erosion
• Applying fertilizer so that less of it is lost

• Desertification:

• Productive potential of topsoil falls by 10% or

• Caused by prolonged drought and human

• Human agriculture accelerates desertification

• Dust bowl:
• Severe wind erosion of topsoil

Excessive Irrigation, Soil Salinization and

• Irrigation has downsides: Most irrigated water is a dilute solution of
various salts

• Water not absorbed leaves behind a crust of mineral salts in the topsoil

• Soil salinization:
• Gradual accumulation of salts in the soil from irrigation water
• Lowers crop yields and eventually kills plants
• Affects 10% of world croplands

• Waterlogging:
• Irrigation water gradually raises water table
• Can deprive plants of oxygen
• Affects 10% of world croplands

Pollution and Climate Change
• Eroded topsoil flows into streams, lakes, and wetlands:

• Aquatic organisms ingest pesticide residues

• Smothers fish and shellfish

• Farmers contribute to pollution through over fertilizing:
• Use of fertilizers has grown forty-five-fold since 1940

• Causes eutrophication

• Nitrates contaminate groundwater used for drinking

Pollution and Climate Change
• Agricultural activities can also cause air pollution:

• Comprise more than 25% of human generated CO2 emissions

• Warms atmosphere and contributes to climate change which can affect crops

Food production and biodiversity loss

• Biodiversity threatened when forest and grasslands replaced
with croplands

• Example: Brazil–areas of the Amazon basin tropical forest are
being lost (burned or cleared for cattle)

• Loss of agrobiodiversity:
• Genetic variety of animal and plant species used on farms to

produce food
• 75% lost since 1900
• For example, India once planted 30,000 varieties of rice–now more

than 75% of its rice production comes in only ten varieties

Controversy over Genetically Engineered Foods
• Genetic engineering could help improve food security

• Little is known about long-term health effects:

• Bt (bacillus thuringiensis) produces a chemical toxin that could trigger inflammatory

• Bt toxin can make leaves more resistant to damage from insects but could threaten human health

• Potential environmental effects of genetically modified populations in the wild:
• Threatens biodiversity and can cause a decline pollinators, which affect plants and animals
• Creating hybrids with natural organisms reduces the natural genetic biodiversity of wild strains

Industrialized Meat Production Harms the
• Pros:

• Increased meat supply

• Reduced overgrazing

• Kept food prices down

Industrialized Meat Production Harms the
• Cons:

• Uses large amounts of water to irrigate grain crops fed to animals
• According to Waterfootprint.org, producing a quarter-pound hamburger requires 1,752

liters (63 gallons) of water

• Livestock wastes pollute waterways and aquatic ecosystems

• Uses large amounts of energy (mostly from oil)

• As part of their digestion process, cattle and dairy cows release methane, a
greenhouse gas with about 25 times the warming potential of CO2 per molecule

• Antibiotic resistance

Environmental Impact of Aquaculture
• Aquaculture produces 47% of the world’s seafood and is

growing rapidly

• By 2030, aquaculture will produce 62% of all seafood

• Several environmental problems:
• Fish are caught to use as feed on fish farms

• Contributes to depletion of wild fish
• Environmental toxins

• Pesticides and antibiotics on fish farms a source of pollution
• Can destroy or degrade mangrove forests (systems are cleared

for aquaculture)

How Can We Protect Crops from Pests More
• Pesticide use can be sharply cut without decreasing crop yields by using a mix

• Cultivation techniques

• Biological pest controls

• Small amounts of selected chemical pesticides as a last resort (integrated pest

Nature Helps Control Many Pests
• Pests: Any species that interferes with human welfare

• Worldwide, only about 100 species of plants (weeds), animals (mostly
insects), fungi, and microbes cause most of the damage to the crops we grow.

• Natural enemies control pest populations:
• Predators, parasites, and disease organisms
• In natural ecosystems
• Free ecosystem service

• Biologists estimate that the world’s 46,700 known species of spiders kill far
more crop-eating insects every year than humans kill with insecticides.

Synthetic Pesticides

• Synthetic pesticides:
• Chemicals used to kill or control pests
• Include insecticides, herbicides, fungicides, and

rodenticides (rats and mouse)
• For nearly 225 million years, plants have been

producing chemicals to ward off, deceive, or poison
the insects and herbivores that feed on them.

• Biopesticides (learning from nature):
• Produced by plants to ward off insects and


Synthetic Pesticides
• First-generation pesticides:

• Borrowed from plants

• Second-generation pesticides: DDT
• Lab produced

• Broad-spectrum agents:
• Can be toxic to beneficial species

• Narrow-spectrum agents

• Persistence varies (length of time they remain deadly in the environment)

Advantages of Synthetic Pesticides
• Human lives saved from malaria (DDT)

• Increase food supplies and reduce food losses due to pests

• Help control erosion and build soil fertility:
• By avoiding plowing because farmers apply herbicide instead of weeding the soil by


• Help farmers reduce costs (higher crop yields)

• Newer pest control methods are safer, faster, and more effective

Disadvantages of Synthetic Pesticides
• Accelerate development of genetic resistance in pests

• Expensive for farmers because of genetic resistance

• Some insecticides kill natural predators or parasites that help control pests

• Cause environmental pollution

• Some harm wildlife

• Some are human health hazards

Alternatives to Synthetic Pesticides

• Pesticides are not necessary to feed the world, they are not tested rigorously for
safety, and there are alternatives.

• Scientists urge to reduce the use of pesticides by using:
• Biological controls

• Natural predators and parasites
• Pheromones and hormones

• Ecological controls
• Use plant diversity to provide habitats for predators of pest species

• Cultivation controls
• Vary crops and adjust planting times to starve pests

Integrated Pest Management

• Integrated pest management (IPM):
• Program in which each crop and its pests are evaluated as parts of an

• When farmers using IPM detect an economically damaging level of pests

in any field, they start with biological methods (natural predators,
parasites, and disease organisms) and cultivation controls (such as
altering planting times and using large machines to vacuum up harmful

• Can reduce pesticide use by 50%
• Goal: Minimal use of synthetic pesticides

Integrated Pest Management
• Disadvantages

• Requires expert knowledge

• Methods applied in one area might not apply in another

• Initial costs higher

How Can We Produce Food More Sustainably?
• We can produce food more sustainably by:

• Using resources more efficiently

• Sharply decreasing the harmful environmental effects of industrialized food

• Eliminating government subsidies that promote such harmful impacts

Conserve Topsoil

• Soil conservation: reducing topsoil erosion and restoring
fertility (keeping land covered with vegetation):

• Terracing
• Contour planting
• Strip cropping with cover crop
• Alley cropping, agroforestry
• Windbreaks or shelterbelts
• Conservation-tillage farming

• Identify erosion hotspots

Restore Soil Fertility
• Another way to protect soil is to restore some of the lost plant nutrients that have been washed,

blown, or leached out of topsoil.

• Organic fertilizer from plant and animal materials:
• Animal manure
• Green manure
• Compost

• Manufactured inorganic fertilizer:
• Nitrogen, phosphorus, and potassium

• Biochar: A form of charcoal made from woody materials

• Crop rotation avoids the depletion of nutrients

Reduce Soil Salinization and Desertification
• Soil salinization:

• Costly solutions

• Desertification (can’t control the timing and location of droughts):
• Reduce

• Population growth
• Overgrazing
• Deforestation
• Destructive forms of planting, irrigation, and mining

• Plant trees that anchor topsoil

Reducing the Environmental Effects of Meat

• Shift from less efficient forms of animal protein to more efficient:
• Pork and poultry are more efficient than beef

• Reduce or eliminate meat intake

• Insects are another source of protein

• Some countries are finding alternatives to grain-based production:
• India’s dairy industry uses crop residues such as rice straw and corn

• Saves energy and reduces greenhouse gas emissions

Shifting to More Sustainable Aquaculture
• Aquaculture Stewardship Council:

• Developed sustainability standards
• Certified <5% of world’s aquaculture operations

• Open-ocean aquaculture (currents wash away fish wastes)

• Inland facilities with recirculating aquaculture
• Water is continually recycled

• Polyaquaculture
• Raise fish or shrimp with algae, seaweed, and shellfish (waste of one species feeds


Expand Organic Agriculture
• Some benefits of organic farming:

• Builds soil organic matter
• Reduces erosion and water pollution
• Uses less fossil fuel energy
• Cuts greenhouse gas emissions
• Match conventional yields
• More weed-tolerant
• Crops compare favorably in years of drought
• More profitable

How Can We Improve Food Security?
• Government policies have controlled food prices and provided subsidies:

• New Zealand and Brazil have ended farm subsidies successfully

• Government and private programs that target poverty can improve food

• Low interest loans

• Immunizations and vitamins for children

Grow and Buy More Food Locally and Cut Food

• Community supported agriculture:
• People buy a share of a local farmer’s crops

• Receive box of produce on a regular basis during
growing season

• Supports local economies and farm families

• Much food waste occurs in restaurants, homes,
and supermarkets:

• 30–40% of food supply thrown away each year

  • Food Resources
  • Why Is Good Nutrition Important?
  • Chronic Hunger and Malnutrition
  • Many People Suffer from Lasting Hunger and Malnutrition
  • Essential Micronutrients
  • Health problems from eating too much food
  • Poverty Is the Root Cause of Hunger and Malnutrition