Geology Reference
In-Depth Information
Table 1 Natural and anthropogenic sources of a selection of trace gases
Compound
Natural sources
Anthropogenic sources
Carbon-containing compounds
Carbon dioxide
(CO
2
)
Respiration; oxidation of
natural CO; destruction of
forests
Combustion of oil, gas, coal
and wood; limestone
burning
Methane (CH
4
)
Enteric fermentation in wild
animals; emissions from
swamps, bogs, etc.,
natural wet land areas;
oceans
Enteric fermentation in
domesticated ruminants;
emissions from paddy
fields; natural gas leakage;
sewerage gas; colliery gas;
combustion sources
Carbon monoxide
(CO)
Forest fires; atmospheric
oxidation of natural
hydrocarbons and
methane
Incomplete combustion of
fossil fuels and wood, in
particular motor vehicles,
oxidation of
hydrocarbons; industrial
processes; blast furnaces
Light paraffins,
C
2
-C
6
Aerobic biological source
Natural gas leakage; motor
vehicle evaporative
emissions; refinery
emissions
Olefins, C
2
-C
6
Photochemical degradation
of dissolved oceanic
organic material
Motor vehicle exhaust; diesel
engine exhaust
Aromatic
hydrocarbons
Insignificant
Motor vehicle exhaust;
evaporative emissions;
paints, gasoline, solvents
Terpenes (C
10
H
16
)
Trees (broadleaf and
coniferous); plants
CFCs and HFCs
None
Refrigerants; blowing agents;
propellants
Nitrogen-containing trace gases
Nitric oxide (NO)
Forest fires; anaerobic
processes in soil; electric
storms
Combustion of oil, gas and
coal
Nitrogen dioxide
(NO
2
)
Forest fires; electric storms
Combustion of oil, gas and
coal; atmospheric
transformation of NO
Nitrous oxide
(N
2
O)
Emissions from denitrifying
bacteria in soil; oceans
Combustion of oil and coal
Ammonia (NH
3
)
Aerobic biological source in
soil. Breakdown of amino
acids in organic waste
material
Coal and fuel oil combustion;
waste treatment
Sulfur-containing trace gases
Dimethyl sulfide
(DMS)
Phytoplankton
Landfill gas
Sulfur dioxide
(SO
2
)
Oxidation of H
2
S; volcanic
activity
Combustion of oil and coal;
roasting sulfide ores
(
Continued
)
