4 Verdrag van Wenen ter bescherming van de ozonlaag
Research and systematic observations
The following chemical substances of natural and anthropogenic origin, not listed in order of priority, are thought to have the potential to modify the chemical and physical properties of the ozone layer.
(a) Carbon substances
(i) Carbon monoxide (CO)
Carbon monoxide has significant natural and anthropogenic sources, and is thought to play a major direct role in tropospheric photochemistry, and an indirect role in stratospheric photochemistry.
(ii) Carbon dioxide (CO2)
Carbon dioxide has significant natural and anthropogenic sources, and affects stratospheric ozone by influencing the thermal structure of the atmosphere.
(iii) Methane (CH4)
Methane has both natural and anthropogenic sources, and affects both tropospheric and stratospheric ozone.
(iv) Non-methane hydrocarbon species
Non-methane hydrocarbon species, which consist of a large number of chemical substances, have both natural and anthropogenic sources, and play a direct role in tropospheric photochemistry and an indirect role in stratospheric photochemistry.
(b) Nitrogen substances
(i) Nitrous oxide (N2O)
The dominant sources of N2O are natural, but anthropogenic contributions are becoming increasingly important. Nitrous oxide is the primary source of stratospheric NOX, which play a vital role in controlling the abundance of stratospheric ozone.
(ii) Nitrogen oxides (NOx)
Ground-level sources of NOX play a major direct role only in tropospheric photochemical processes and an indirect role in stratosphere photochemistry, whereas injection of NOX close to the tropopause may lead directly to a change in upper tropospheric and stratospheric ozone.
(c) Chlorine substances
(i) Fully halogenated alkanes, e.g. CCI4, CFC13, (CFC-11), CF2CI2, (CFC-12), C2F3CI3 (CFC-113), C2F4CI2 (CFC-114)
Fully halogenated alkanes are anthropogenic and act as a source of C10x, which plays a vital role in ozone photochemistry, especially in the 30-50 km altitude region.
(ii) Partially halogenated alkanes, e.g. CH3CI, CHF2CI (CFC-22), CH3CCI3, CHFCI2 (CFC-21)
The sources of CH3CI are natural, whereas the other partially halogenated alkanes mentioned above are anthropogenic in origin. These gases also act as a source of stratospheric C1OX.
(d) Bromine substances
Fully halogenated alkanes, e.g. CF3Br
These gases are anthropogenic and act as a source of BrOx, which behaves in a manner similar to CIOX.
(e) Hydrogen substances
(i) Hydrogen (H2)
Hydrogen, the source of which is natural and anthropogenic, plays a minor role in stratospheric photochemistry.
(ii) Water (H2O)
Water, the source of which is natural, plays a vital role in both tropospheric and stratospheric photochemistry. Local sources of water vapour in the stratosphere include the oxidation of methane and, to a lesser extent, of hydrogen.
- Regeling
- Verdrag van Wenen ter bescherming van de ozonlaag
- Soort
- Verdrag
- Geldend vanaf
- 27-12-1988
- BWB-id
- BWBV0002799
- Versie
- 1988-12-27_0