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

Nonrenewable Natural Resource

Replenished over short periods of time

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 (hectaresha)

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%20Science%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