processes and are also used in manufacturing. They do not significantly
deplete the stratospheric ozone layer, but they are powerful greenhouse
gases with global warming potentials ranging from 140 (HFC-152a) to
11,700 (HFC-23).
Hydrofluoroolefin (HFO)
A compound consisting of hydrogen, fluorine, and carbon. Hydrofluoroolefins
(HFOs) are alternatives to ozone-depleting substances that typically have very
low global warming potentials.
Hydrologic cycle The process of evaporation, vertical and horizontal transport of vapor, condensation, precipitation, and the flow of water from continents to oceans. It is
a major factor in determining climate through its influence on surface vegetation, the clouds, snow and ice, and soil moisture. The hydrologic cycle is
responsible for 25 to 30 percent of the midlatitudes’ heat transport from the
equatorial to polar regions.
Hydrosphere
The component of the climate system comprising liquid surface and subterranean water, such as oceans, seas, rivers, freshwater lakes, underground
water, etc.
Ice core
A cylindrical section of ice removed from a glacier or an ice sheet in order to
study climate patterns of the past. By performing chemical analyses on the air
trapped in the ice, scientists can estimate the percentage of carbon dioxide and
other trace gases in the atmosphere at a given time. Analysis of the ice itself
can give some indication of historic temperatures.
Indicator
An observation or calculation that allows scientists, analysts, decisionmakers, and others to track environmental trends, understand key factors
that influence the environment, and identify effects on ecosystems and
society.
Indirect
emissions
Indirect emissions from a building, home, or business are those emissions of
greenhouse gases that occur as a result of the generation of electricity used in
that building. These emissions are called “indirect” because the actual emissions occur at the power plant which generates the electricity, not at the
building using the electricity.
Industrial
revolution
A period of rapid industrial growth with far-reaching social and economic
consequences, beginning in England during the second half of the eighteenth
century and spreading to Europe and later to other countries including the
USA. The industrial revolution marks the beginning of a strong increase in
combustion of fossil fuels and related emissions of carbon dioxide.
Infrared
radiation
Infrared radiation consists of light whose wavelength is longer than the red
color in the visible part of the spectrum, but shorter than microwave radiation.
Infrared radiation can be perceived as heat. The earth’s surface, the atmosphere, and clouds all emit infrared radiation, which is also known as terrestrial or long-wave radiation. In contrast, solar radiation is mainly short-wave
radiation because of the temperature of the Sun.
Intergovernmental Panel on
Climate Change
(IPCC)
The IPCC was established jointly by the United Nations Environment
Programme and the World Meteorological Organization in 1988. The purpose
of the IPCC is to assess information in the scientific and technical literature
related to all significant components of the issue of climate change. The IPCC
draws upon hundreds of the world’s expert scientists as authors and thousands
as expert reviewers. Leading experts on climate change and environmental,
social, and economic sciences from some 60 nations have helped the IPCC to
prepare periodic assessments of the scientific underpinnings for understanding
global climate change and its consequences. With its capacity for reporting on
climate change, its consequences, and the viability of adaptation and mitigation measures, the IPCC is also looked to as the official advisory body to the
world’s governments on the state of the science of the climate change issue.
30
L. K. Wang et al.
deplete the stratospheric ozone layer, but they are powerful greenhouse
gases with global warming potentials ranging from 140 (HFC-152a) to
11,700 (HFC-23).
Hydrofluoroolefin (HFO)
A compound consisting of hydrogen, fluorine, and carbon. Hydrofluoroolefins
(HFOs) are alternatives to ozone-depleting substances that typically have very
low global warming potentials.
Hydrologic cycle The process of evaporation, vertical and horizontal transport of vapor, condensation, precipitation, and the flow of water from continents to oceans. It is
a major factor in determining climate through its influence on surface vegetation, the clouds, snow and ice, and soil moisture. The hydrologic cycle is
responsible for 25 to 30 percent of the midlatitudes’ heat transport from the
equatorial to polar regions.
Hydrosphere
The component of the climate system comprising liquid surface and subterranean water, such as oceans, seas, rivers, freshwater lakes, underground
water, etc.
Ice core
A cylindrical section of ice removed from a glacier or an ice sheet in order to
study climate patterns of the past. By performing chemical analyses on the air
trapped in the ice, scientists can estimate the percentage of carbon dioxide and
other trace gases in the atmosphere at a given time. Analysis of the ice itself
can give some indication of historic temperatures.
Indicator
An observation or calculation that allows scientists, analysts, decisionmakers, and others to track environmental trends, understand key factors
that influence the environment, and identify effects on ecosystems and
society.
Indirect
emissions
Indirect emissions from a building, home, or business are those emissions of
greenhouse gases that occur as a result of the generation of electricity used in
that building. These emissions are called “indirect” because the actual emissions occur at the power plant which generates the electricity, not at the
building using the electricity.
Industrial
revolution
A period of rapid industrial growth with far-reaching social and economic
consequences, beginning in England during the second half of the eighteenth
century and spreading to Europe and later to other countries including the
USA. The industrial revolution marks the beginning of a strong increase in
combustion of fossil fuels and related emissions of carbon dioxide.
Infrared
radiation
Infrared radiation consists of light whose wavelength is longer than the red
color in the visible part of the spectrum, but shorter than microwave radiation.
Infrared radiation can be perceived as heat. The earth’s surface, the atmosphere, and clouds all emit infrared radiation, which is also known as terrestrial or long-wave radiation. In contrast, solar radiation is mainly short-wave
radiation because of the temperature of the Sun.
Intergovernmental Panel on
Climate Change
(IPCC)
The IPCC was established jointly by the United Nations Environment
Programme and the World Meteorological Organization in 1988. The purpose
of the IPCC is to assess information in the scientific and technical literature
related to all significant components of the issue of climate change. The IPCC
draws upon hundreds of the world’s expert scientists as authors and thousands
as expert reviewers. Leading experts on climate change and environmental,
social, and economic sciences from some 60 nations have helped the IPCC to
prepare periodic assessments of the scientific underpinnings for understanding
global climate change and its consequences. With its capacity for reporting on
climate change, its consequences, and the viability of adaptation and mitigation measures, the IPCC is also looked to as the official advisory body to the
world’s governments on the state of the science of the climate change issue.
30
L. K. Wang et al.