Science%20and%20the%20Environment

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Chapter 1

• Science and the Environment

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Understanding Our Environment

• Environment a complex web of relationships that
  connects us with the world we live in
• Environmental Science the study of how humans
  interact with the environment

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Goals of Environmental Science

• To understand and solve environmental problems
• We must be able to identify causes and describe
  solutions

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Human Impact

• Humans live within the worlds ecosystems and
  therefore change them as a result of population
  growth, technology, and consumption
• Problems habitat destruction, pollution,
  atmospheric changes, over fishing the oceans,
  poaching, etc.

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Consequences

• If environmental problems are not addressed,
  ecosystems will be irreversibly damaged
• Human populations NEED natural resources in order
  to maintain and improve their existence

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Misconception

• News stories often focus on efforts to save
  threatened or endangered species
• There can also be problems with overpopulation of
  species within an ecosystem
• Ex zebra mussels, house sparrows, European
  starlings, fire ants, kudzu vine

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Many Fields of Study

• Environmental science is an interdisciplinary
  science (involves many fields of study)
• ECOLOGY the study of how living things interact
  with each other and with the nonliving environment

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Major Fields of Study

• Biology study of living organisms
• Earth Science study of the Earths nonliving
  systems and the planet as a whole
• Physics study of matter and energy
• Chemistry study of chemicals and their
  interaction
• Social Science study of human populations

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Scientists as Citizens

• Studying our environment is vital to maintaining
  a healthy and productive society
• Observations by nonscientists are often the first
  step of addressing a problem

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Our Environment Through Time

• Humans have always altered the environment to
  suit their needs, often without a regard for its
  long-term impacts
• Early humans were hunter-gatherers (H-G)
• (they obtained food by collecting plants and
  by hunting animals or scavenging their remains)

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Hunter-Gatherers (H-G)

• Early H-G groups were small and migrated from
  place to place depending on food abundance
• Some H-G societies today include aborigines and
  tribes in New Guinea

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Extinction

• Rapid climate change and over-hunting of some
  species led to their extinction
• Examples mastodons and mammoths

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Conservation

• Some H-G groups were very aware of the need for
  conservation
• Native Americans did not kill what they could not
  use
• Although they hunted buffalo, it was the American
  settlers who slaughtered them nearly to the point
  of extinction

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Agricultural Revolution

• H-G began collecting seeds to plant and
  domesticating animals to raise food
• Agriculture began more than 10,000 years ago

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Agricultural Revolution

• Through agriculture, an area of land was able to
  support 500X as many people
• As populations grew, they began to concentrate in
  smaller areas which placed pressure on
  surrounding environments

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Slash-and-Burn Agriculture

• Causes many areas to become unusable after a few
  years
• Common in rainforest areas

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Industrial Revolution

• Mid 1700s shift from energy sources such as
  animal muscle and running water to fossil fuels
  (coal, oil, natural gas)
• Caused major changes in society
• Increased the efficiency of agriculture,
  transportation, and industry

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Industrial Revolution (I-R)

• Large-scale production of goods became common
• Farm machinery decreased the amount of human
  workers needed

• Cotton picked by slaves vs. cotton gin

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Environmental Consequences

• Transportation rapidly developed allowing
  products to be distributed over greater distances
• As people experienced a new standard of living,
  the environment suffered at our expense

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Salt and Pepper Moth(Biston betularia)

• H.G. Kettlewells study both white and black
  moths exist
• BEFORE I-R, white moths were more common
  (camouflaged on white tree bark with lichens)
• AFTER I-R, black moths were more common
  (camouflaged on soot covered tree bark)

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Improving Quality of Life

• I-R introduced many changes that improved human
  lives such as indoor plumbing, nutrition, and
  medical care
• As human populations grow, environmental problems
  increase

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Rachel Carson

• By the 1900s, pesticides were widely used and
  caused many health problems that were ignored
• Rachel Carson wrote Silent Spring (1962) which
  called attention to the misuse of pesticides and
  began the environmental movement

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Spaceship Earth

• Earth is compared to a ship traveling through
  space that cannot dispose of waste or take on new
  supplies
• Closed system the only thing that enters is
  solar energy and the only thing that leaves is
  heat

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Closed System

• Resources can be used up!
• Wastes are produced faster than we can dispose
  of them

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Environmental Problems

• Exist on three different scales local, regional,
  and global
• LOCAL Columbiana County
• REGIONAL Northeast Ohio
• GLOBAL Affects the world

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Main Environmental Problems

• Resource depletion
• Pollution
• Extinction

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Resource Depletion

• Natural resources any natural substance that
  living things can use
• Examples air, water, sunlight, soil, minerals,
  plants, animals, forests, and fossil fuels
• When a resource is used up faster than it can be
  replaced, it will become depleted!

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Renewable Resources

• Resources that are continually being replaced
• Examples solar energy, water, soil, air, crops,
  livestock, trees
• Can still be depleted if not managed properly

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Nonrenewable Resources

• Resources that cannot be replacedonce depleted,
  they are gone FOREVER!
• Examples metals such as iron, copper, and
  aluminum, minerals such as salt, sand, and clay,
  fossil fuels

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Pollution

• Contamination of our air, water, or soil that
  affects the health, survival, or activities of
  humans or other organisms
• Human byproducts are the main causes of pollution
• Examples pesticides, radiation, petroleum
  products, PCBs, mercury, CO2

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Biodegradable Pollutants

• Pollutants that can be broken down by natural
  processes
• Example human sewage

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Nondegradable Pollutants

• Pollutants that do not break down easily
• Accumulate in the environment at dangerous levels
• Examples pesticides, mercury, lead, PCBs

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Loss of Biodiversity

• Biodiversity the number and variety of species
  that live in an area
• Many species become extinct due to habitat
  destruction or polluted ecosystems

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Extinction

• Every last individual of a species has died and
  the species is gone forever
• Examples dodo, passenger pigeon, great auk
• Animals and plants are natural resources that we
  depend on to exist

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Biosphere

• All life on Earth AND the physical environment
  that supports it
• Damage to any part of an ecosystem can have a
  ripple effect that can negatively impact the
  entire biosphere
• What can YOU do to help protect the world?