Summary
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The Atmosphere and Climate 218- Weather is the condition in the atmosphere at a given
place and time; it includes temperature, atmospheric
pressure, precipitation, cloudiness, humidity, and wind. Earth’s
overall climate is determined by the sun’s intensity, Earth’s
distance from the sun, tilt of the Earth relative to its rotational
axis, distribution of water and landmasses across Earth’s
surface, and composition of gases in Earth’s atmosphere.
The typical weather patterns that occur over a period of years
determine a region’s climate. The two most important
factors that define an area’s climate are temperature
and precipitation. - Sunlight, or insolation, is the primary (almost sole) source
of energy available in the biosphere. The sun’s energy runs
the hydrologic cycle, drives winds and ocean currents,
powers photosynthesis, and warms the planet. Of the
solar energy that reaches Earth, 31 percent is immediately
reflected away, and the remaining 69 percent is absorbed.
Ultimately, all absorbed solar energy is radiated into space
as infrared radiation, electromagnetic radiation with
wavelengths longer than those of visible light but shorter
than microwaves. - Precipitation is greatest where warm air passes over the
ocean, absorbing moisture, and is then cooled, such as
when mountains force humid air upward. Deserts develop
in the rain shadows of mountain ranges or in continental
interiors.
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Global Climate Change 222- Greenhouse gases are gases that absorb infrared
radiation; they include carbon dioxide, methane, nitrous
oxide, chlorofluorocarbons, and tropospheric ozone. The
enhanced greenhouse effect is the additional warming
produced as human activities increase the amount of gases
that absorb infrared radiation. Radiative forcing is the term
used to describe the ability of different gases to cause the
atmosphere to retain heat. - Global climate change will continue to cause sea level to
rise, precipitation patterns to alter, extinction of many
species, and problems for agriculture. It could result in
the displacement of millions of people, thereby increasing
international tensions.
✓✓THE PLANNER
- Mitigation (slowing down the rate of global climate change)
and adaptation (making adjustments to live with climate
change) are two ways to address climate change. Mitigation
includes developing alternatives to fossil fuels; increasing
energy efficiency of automobiles and appliances; planting and
maintaining forests; and instigating carbon management,
by finding ways to separate and capture the CO 2 produced
during the combustion of fossil fuels and then sequester it.
Adaptation includes strategies to help various regions and
sectors of society prepare for warmer temperatures, higher
sea level, and altered precipitation patterns.
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Ozone Depletion in the
Stratosphere 231- Ozone (O 3 ) is a human-made pollutant in the troposphere
but a naturally produced, essential component in the
stratosphere. The stratosphere contains a layer of ozone
that shields the surface from much of the Sun’s ultraviolet
(UV) radiation, that part of the electromagnetic spectrum
with wavelengths just shorter than those of visible light; UV
radiation is a high-energy form of radiation that can cause
skin cancer in humans, and be lethal to organisms at high
levels of exposure. - Ozone thinning is the natural and human-caused removal
of ozone from the stratosphere. The primary chemicals
responsible for ozone thinning in the stratosphere are
chlorofluorocarbons (CFCs), human-made organic aerosol
compounds that contain chlorine and fluorine. CFCs are now
banned because they attack the stratospheric ozone layer.
Ozone thinning causes excessive exposure to UV radiation,
which can increase cataracts, weaken immunity, and cause
skin cancer in humans. Increased levels of UV radiation may
also disrupt ecosystems. - The Montreal Protocol is an international agreement that
has phased out much CFC production worldwide, leading to
decreased stratospheric ozone thinning.
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Acid Deposition 234- Acid deposition is a type of air pollution that includes
sulfuric and nitric acids in precipitation as well as dry acid
particles that settle out of the air. Acid deposition develops
Summary 239