Transcript Studying the State of our Earth

Studying the State of our Earth
Chapter 1
What is Environmental Science?
• Environmental Science: field that looks at
interactions among human systems and those
found in nature
http://bcs.whfreeman.com/friedlandapes/#t_668210____
Natural Resources
Renewable Natural
Resource
Replenished over short
periods of time
Nonrenewable Natural
Resource
Available in finite supply
and formed much more
slowly
Once depleted, no longer
available
Sunlight, wind, soil, water
Mineral ores, crude oil
• System: set of interacting components that
influence one another by exchanging energy or
materials
a. environmental system (man-made or natural)
- ecosystem: includes biotic and abiotic
components
Humans Altering Natural Systems
• Humans manipulate environment more than any
other species intentionally and unintentionally
• Human activities have created opportunities for
certain species to thrive
• As the human population grows, their effect on
the environment will grow
• Environmental services: provided by natural
environment such as clean water, timber, fisheries
• Environmental indicators: describe current state of
environment
ex) human population, extinction rate
- used to help guide towards sustainability
- five global (biodiversity, food production, carbon
dioxide concentrations, human population and
resource depletion)
Biological Diversity or Biodiversity
• “diversity of life forms in an environment”
• 3 scales
a. genetic, species, and ecosystem diversity
• Important indicator of environmental health
and quality
• Genetic diversity: measure of genetic variation
among individuals in a population
a. high genetic diversity = responding to
environmental change
• Species Diversity: number of species in a
region or in a particular type of habitat
a. critical environmental indicator
ex) frogs for environmental health
b. speciation: evolution of new species
http://blogs.thehindu.com/delhi/?p=13294
• Ecosystem diversity: measure of the diversity
of ecosystems or habitats that exist in a given
region
a. land area is used as a measurement of
biodiversity (hectaresha)
Food Production
• Ability to grow food and nourish the human
population
• Wheat, corn and rice
• Food shortages have led to higher food prices
http://www.goldismoney2.com/showthread.php?8330-A-world-wide-food-shortage-will-it-hit-here
Average Global Surface Temperature and Carbon
Dioxide Concentrations
• Greenhouse gases: heat trapping gases
ex) CO2
a. help keep Earth’s surface within a range of
temperatures
b. have risen over time (anthropogenic reasons)
http://content.bfwpub.com/webroot_pubcontent/Content/BCS_4/Friedland,%20Environmental%20Scien
ce%20AP/Art%20Notebook/friedland_ch01.pdf
Human Population
• Current population: 6.9 billion and growing
• Agricultural Revolution
• Industrial Revolution
Resource Depletion
• As the human population increases, the resources
needed for survival decreases
• Renewable (timber) and nonrenewable (coal)
• Tragedy of the Commons
- resources become overused due to unregulated
exploitation
- Garret Hardin
- Easter Island
http://www.cnn.com/2013/01/02/travel/easter-island-travel/index.html
Ecological Footprint
• “the output from the total amount of land
required to support a person’s lifestyle”
• Unsustainable living v. Sustainable living
• Human Ecological Footprint = 14 billion hectares
(______ acres?)
 125% of Earth’s total usable land area
Scientific Method
http://www.sciencebuddies.org/science-fair-projects/project_scientific_method.shtml
Controlled v. Natural Experiments
• Controlled Experiments
a. controlled settings such as laboratory
• Natural Experiments
a. environment
b. example: volcano destroying large amounts
of land showing forest regrowth
Unique Challenges in Environmental
Science
•
•
•
•
Lack of Baseline data: no “control planet”
Subjectivity
Interactions
Human Well-Being
Sustainable Development
• Obtained 3 ways
a. environmental systems must not be damaged
beyond their ability to recover
b. renewable resources must not be depleted
faster than they can regenerate
c. nonrenewable resources must be used
sparingly