Page 63 - Environment: The Science Behind the Stories

analyzing agricultural practices, managing water resources, ever-increasing demand for energy, understanding the nature
reforming energy policy, conducting toxicological studies, of energy is vital to a sustainable future.
and finding ways to mitigate global climate change. Physical processes of geology such as plate tectonics
Likewise, an understanding of energy is both of funda- and the rock cycle are centrally important because they shape
mental scientific importance and of considerable practical Earth’s terrain and form the foundation for living systems that
relevance. For example, can Japan (whose nuclear reactors overlie the landscape. But geologic processes also generate
supplied one-third of its electricity prior to the Tohoku quake) phenomena that can threaten our lives and property, including
or any other nation transition from fossil fuels to energy earthquakes, volcanoes, landslides, and tsunamis. The Tohoku
sources that do not emit greenhouse gases if nuclear power quake also showed how geological processes in one location
is not a part of that transition? Can we develop new technolo- (an earthquake and tsunami in Japan) can initiate events whose
gies and approaches that maximize energy conversion effi- impacts (global perceptions of the safety of nuclear power) go
ciency? As population increase and economic growth lead to far beyond that location.

Reviewing Objectives

You should now be able to: Distinguish photosynthesis, cellular respiration, and
chemosynthesis and summarize their importance to
Explain the fundamentals of matter and chemistry and living things
apply them to real-world situations
• In photosynthesis, autotrophs use carbon dioxide, water,
• Understanding matter and chemistry is important for devel- and solar energy to produce oxygen and the sugars they
oping solutions to environmental problems. (p. 41) need. (p. 50)
• Matter in the universe is conserved; it cannot be created or • In cellular respiration, organisms extract energy from sug-
destroyed. (p. 41) ars by converting them in the presence of oxygen into car-
bon dioxide and water. (p. 50)
• Atoms can form molecules and compounds, and changes at
the atomic level can result in alternate forms of elements, • In chemosynthesis, specialized autotrophs use carbon
such as ions and isotopes. (pp. 41–44) dioxide, water, and chemical energy from minerals to pro-
duce sugars. (p. 51)
• Water’s chemistry facilitates life. (pp. 44–45)
• The pH scale quantifies acidity and alkalinity. (pp. 45–46)
Explain how plate tectonics and the rock cycle shape
• Living things depend on organic compounds, which are the landscape around us and the earth beneath our
carbon-based. (pp. 46–47) feet

• Macromolecules, including proteins, nucleic acids, carbo- • Earth consists of distinct layers that differ in composition,
hydrates, and lipids, are key building blocks of life. (p. 47) temperature, density, and other characteristics. (p. 52)
• Plate tectonics is a fundamental system that shapes
Differentiate among forms of energy and explain the Earth’s physical geography and produces earthquakes and
basics of energy flow
volcanoes. (p. 52)
• Energy can convert from one form to another—for • Tectonic plates meet at three types of boundaries: divergent,
instance, from potential to kinetic energy, and vice versa. transform, and convergent. (pp. 52–54)
Chemical energy is potential energy in the bonds between
atoms. (pp. 47–49) • Matter is cycled within the lithosphere, and rocks trans-
form from one type to another. (pp. 54–57)
• The total amount of energy in the universe is conserved; it
cannot be created or destroyed. (p. 48)
List major types of geologic hazards and describe
• Systems tend to increase in entropy, or disorder, unless ways to mitigate their impacts
energy is added to build or maintain order and complexity.
(pp. 48–49) • The circum-Pacific belt, or “ring of fire,” spawns most of
the world’s volcanoes and earthquakes. (pp. 57–58)
• Earth’s systems are powered mainly by radiation from
the sun, geothermal heating from the planet’s core, and • Earthquakes result from movement at faults and plate
gravitational interactions among Earth, the sun, and the boundaries. We cannot prevent them, but we can build
moon. (pp. 49–51) structures and cities in safer ways. (p. 58)
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