For example, the IPCC organized the development of internationally accepted
methods for conducting national greenhouse gas emission inventories.
Kyoto Protocol
An international treaty that sets obligations and industrialized countries to
lower their emissions of greenhouse gases.
Mesosphere
Earth’s atmosphere is divided into five main layers: the exosphere, the
thermosphere, the mesosphere, the stratosphere, and the troposphere. Stratosphere is the region of the atmosphere above the troposphere. Mesosphere is
the region of the atmosphere above the stratosphere, but below thermosphere.
Methane (CH 4 )
(a) Colorless, odorless, flammable hydrocarbon (CH 4 ) that is a product of
decomposition of organic matter and of the carbonization of coal. Methane is
one of the greenhouse gas chemical compounds. (b) A hydrocarbon that is a
greenhouse gas with a global warming potential most recently estimated at
25 times that of carbon dioxide (CO 2 ). Methane is produced through anaerobic (without oxygen) decomposition of waste in landfills, animal digestion,
decomposition of animal wastes, production and distribution of natural gas
and petroleum, coal production, and incomplete fossil fuel combustion.
Natural gas
Underground deposits of gases consisting of 50 to 90 percent methane (CH 4 )
and small amounts of heavier gaseous hydrocarbon compounds such as
propane (C 3 H 8 ) and butane (C 4 H 10 ).
Natural
variability
Variations in the mean state and other statistics (such as standard deviations or
statistics of extremes) of the climate on all time and space scales beyond that
of individual weather events. Natural variations in climate over time are
caused by internal processes of the climate system, such as El Niño, as well
as changes in external influences, such as volcanic activity and variations in
the output of the sun.
Nitrogen cycle
The natural circulation of nitrogen among the atmosphere, plants, animals,
and microorganisms that live in soil and water. Nitrogen takes on a variety of
chemical forms throughout the nitrogen cycle, including nitrous oxide (N 2 O)
and nitrogen oxides (NOx).
Nitrogen oxides
(NOx)
Gases consisting of one molecule of nitrogen and varying numbers of oxygen
molecules. Nitrogen oxides are produced in the emissions of vehicle exhausts
and from power stations. In the atmosphere, nitrogen oxides can contribute to
formation of photochemical ozone (smog), can impair visibility, and have
health consequences; they are thus considered pollutants.
Nitrous oxide
(N 2 O)
A powerful greenhouse gas with a global warming potential of 298 times that
of carbon dioxide (CO 2 ). Major sources of nitrous oxide include soil cultivation practices, especially the use of commercial and organic fertilizers, fossil
fuel combustion, nitric acid production, and biomass burning. The GWP is
from the IPCC’s Fourth Assessment Report (AR4). Natural emissions of N 2 O
are mainly from bacteria breaking down nitrogen in soils and the oceans.
Nitrous oxide is mainly removed from the atmosphere through destruction in
the stratosphere by ultraviolet radiation and associated chemical reactions, but
it can also be consumed by certain types of bacteria in soils.
Non-methane
volatile organic
compounds
(NMVOCs)
Organic compounds, other than methane, that participate in atmospheric
photochemical reactions.
Nutrients
Chemicals (such as nitrogen and phosphorus) that plants and animals need to
live and grow. At high concentrations, particularly in water, nutrients can
become pollutants.
Ocean
acidification
(a) Increased concentrations of carbon dioxide in seawater causing a measurable increase in acidity (i.e., a reduction in ocean pH). This may lead to
reduced calcification rates of calcifying organisms such as corals, mollusks,
1 Effect of Global Warming and Climate Change on Glaciers and Salmons
31
methods for conducting national greenhouse gas emission inventories.
Kyoto Protocol
An international treaty that sets obligations and industrialized countries to
lower their emissions of greenhouse gases.
Mesosphere
Earth’s atmosphere is divided into five main layers: the exosphere, the
thermosphere, the mesosphere, the stratosphere, and the troposphere. Stratosphere is the region of the atmosphere above the troposphere. Mesosphere is
the region of the atmosphere above the stratosphere, but below thermosphere.
Methane (CH 4 )
(a) Colorless, odorless, flammable hydrocarbon (CH 4 ) that is a product of
decomposition of organic matter and of the carbonization of coal. Methane is
one of the greenhouse gas chemical compounds. (b) A hydrocarbon that is a
greenhouse gas with a global warming potential most recently estimated at
25 times that of carbon dioxide (CO 2 ). Methane is produced through anaerobic (without oxygen) decomposition of waste in landfills, animal digestion,
decomposition of animal wastes, production and distribution of natural gas
and petroleum, coal production, and incomplete fossil fuel combustion.
Natural gas
Underground deposits of gases consisting of 50 to 90 percent methane (CH 4 )
and small amounts of heavier gaseous hydrocarbon compounds such as
propane (C 3 H 8 ) and butane (C 4 H 10 ).
Natural
variability
Variations in the mean state and other statistics (such as standard deviations or
statistics of extremes) of the climate on all time and space scales beyond that
of individual weather events. Natural variations in climate over time are
caused by internal processes of the climate system, such as El Niño, as well
as changes in external influences, such as volcanic activity and variations in
the output of the sun.
Nitrogen cycle
The natural circulation of nitrogen among the atmosphere, plants, animals,
and microorganisms that live in soil and water. Nitrogen takes on a variety of
chemical forms throughout the nitrogen cycle, including nitrous oxide (N 2 O)
and nitrogen oxides (NOx).
Nitrogen oxides
(NOx)
Gases consisting of one molecule of nitrogen and varying numbers of oxygen
molecules. Nitrogen oxides are produced in the emissions of vehicle exhausts
and from power stations. In the atmosphere, nitrogen oxides can contribute to
formation of photochemical ozone (smog), can impair visibility, and have
health consequences; they are thus considered pollutants.
Nitrous oxide
(N 2 O)
A powerful greenhouse gas with a global warming potential of 298 times that
of carbon dioxide (CO 2 ). Major sources of nitrous oxide include soil cultivation practices, especially the use of commercial and organic fertilizers, fossil
fuel combustion, nitric acid production, and biomass burning. The GWP is
from the IPCC’s Fourth Assessment Report (AR4). Natural emissions of N 2 O
are mainly from bacteria breaking down nitrogen in soils and the oceans.
Nitrous oxide is mainly removed from the atmosphere through destruction in
the stratosphere by ultraviolet radiation and associated chemical reactions, but
it can also be consumed by certain types of bacteria in soils.
Non-methane
volatile organic
compounds
(NMVOCs)
Organic compounds, other than methane, that participate in atmospheric
photochemical reactions.
Nutrients
Chemicals (such as nitrogen and phosphorus) that plants and animals need to
live and grow. At high concentrations, particularly in water, nutrients can
become pollutants.
Ocean
acidification
(a) Increased concentrations of carbon dioxide in seawater causing a measurable increase in acidity (i.e., a reduction in ocean pH). This may lead to
reduced calcification rates of calcifying organisms such as corals, mollusks,
1 Effect of Global Warming and Climate Change on Glaciers and Salmons
31