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| Titel |
The impact of air pollutant and methane emission controls on tropospheric ozone and radiative forcing: CTM calculations for the period 1990-2030 |
| VerfasserIn |
F. Dentener, D. Stevenson, J. Cofala, R. Mechler, M. Amann, P. Bergamaschi, F. Raes, R. Derwent |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 5, no. 7 ; Nr. 5, no. 7 (2005-07-15), S.1731-1755 |
| Datensatznummer |
250002978
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| Publikation (Nr.) |
 copernicus.org/acp-5-1731-2005.pdf |
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| Zusammenfassung |
| To explore the relationship between tropospheric ozone and radiative forcing
with changing emissions, we compiled two sets of global scenarios for the
emissions of the ozone precursors methane (CH4), carbon monoxide (CO),
non-methane volatile organic compounds (NMVOC) and nitrogen oxides
(NOx) up to the year 2030 and implemented them in two global Chemistry
Transport Models. The "Current Legislation" (CLE) scenario reflects the
current perspectives of individual countries on future economic development
and takes the anticipated effects of presently decided emission control
legislation in the individual countries into account. In addition, we
developed a "Maximum technically Feasible Reduction" (MFR) scenario that
outlines the scope for emission reductions offered by full implementation of
the presently available emission control technologies, while maintaining the
projected levels of anthropogenic activities. Whereas the resulting
projections of methane emissions lie within the range suggested by other
greenhouse gas projections, the recent pollution control legislation of many
Asian countries, requiring introduction of catalytic converters for
vehicles, leads to significantly lower growth in emissions of the air
pollutants NOx, NMVOC and CO than was suggested by the widely used and
more pessimistic IPCC (Intergovernmental Panel on Climate Change) SRES
(Special Report on Emission Scenarios) scenarios
(Nakicenovic et al., 2000), which made Business-as-Usual assumptions
regarding emission control technology. With the TM3 and STOCHEM models we
performed several long-term integrations (1990-2030) to assess global,
hemispheric and regional changes in CH4, CO, hydroxyl radicals, ozone
and the radiative climate forcings resulting from these two emission
scenarios. Both models reproduce broadly the observed trends in CO, and
CH4 concentrations from 1990 to 2002.
For the "current legislation" case, both models indicate an increase of
the annual average ozone levels in the Northern Hemisphere by 5ppbv, and up
to 15ppbv over the Indian sub-continent, comparing the 2020s (2020-2030)
with the 1990s (1990-2000). The corresponding higher ozone and methane
burdens in the atmosphere increase radiative forcing by approximately 0.2 Wm-2.
Full application of today's emissions control technologies,
however, would bring down ozone below the levels experienced in the 1990s
and would reduce the radiative forcing of ozone and methane to approximately
-0.1 Wm-2. This can be compared to the 0.14-0.47 Wm-2 increase of
methane and ozone radiative forcings associated with the SRES scenarios.
While methane reductions lead to lower ozone burdens and to less radiative
forcing, further reductions of the air pollutants NOx and NMVOC result
in lower ozone, but at the same time increase the lifetime of methane.
Control of methane emissions appears an efficient option to reduce
tropospheric ozone as well as radiative forcing. |
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