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____

Renewable Natural Resource Nonrenewable Natural Resource 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 Intentionally: adding fertilizers Unintenionally: consequence of activities that generate pollution Thrive: certain fires have kept trees from coming in on the great plains therefore leaving room for an ecosystem to develop creating a home for new species

Environmental indicators: describe current state of environment 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) Indicators don’t always tell what is causing the change but can give an idea of when we need to dig deeper and look closer at a particular issue Sustainability: living on earth in a way that allows us to use its resources without depriving future generations of those resources

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

a. critical environmental indicator ex) frogs for environmental health 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 Species: paritcular group of organisms that are distinct from other groups http://blogs.thehindu.com/delhi/?p=13294

a. land area is used as a measurement of biodiversity (hectaresha) 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) Greater number of healthy and productive ecosystems means a healthier environment overall

Food Production Ability to grow food and nourish the human population Wheat, corn and rice Food shortages have led to higher food prices Wheat corn and rice provide more than half the calories and protein humans consume Grain production is influenced by climatic conditions, amount and quality of land under cultivation irrigation and human labor and energy required to plant harvest and bring grain to market 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 Easter Island Used to be lush with forests and inhabitated thousands of people but then they overused their resources by cutting down all of the trees leading themselves into starvation and conflict

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 Unsustainable: lifestyle requires more land than is available therefore using up resources more quickly than they can be produced If every person on earth lived the average lifestyle of people in the US, we would need around 5 earths

Scientific Method Case Study: The Chlorphyrifos Investigation Organophosphates may have serious effects on human central nervous system Experimental group: rats fed small doses of chlorpyrifos and control group: no drug * Performed in controlled conditions 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 Baseline data: every part of the earth has been altered in some state by humans Subjectivity: different substances tend to affect the environment differently Interactions: very complex

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