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| Titel |
The state of greenhouse gases in the atmosphere using global observations through 2008 |
| VerfasserIn |
Oksana A. Tarasova, Geir O. Braathen, Leonard A. Barrie, Kazuto Suda, Edward Dlugokencky |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250034977
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| Zusammenfassung |
| The Global Atmosphere Watch Programme of the World Meteorological Organization is the
only existing long-term international global programme providing a framework for observing
and assessing the state and development of environmental issues related to greenhouse gases
and climate change. The WMO-GAW Global Greenhouse Gas Monitoring Network, a
comprehensive network of the Global Climate Observing System (GCOS), integrates the
observations from different platforms (surface-based, aircraft and satellite). Surface
observations are made at about 180 stations for CO2. The latest analysis shows that the
globally averaged mixing ratios of carbon dioxide (CO2), methane (CH4) and nitrous oxide
(N2O) have reached new highs in 2008 with CO2 at 385.2 ppm, CH4 at 1797 ppb and N2O
at 321.8 ppb: higher than those in pre-industrial times (before 1750) by 38%, 157%
and 19%, respectively. Atmospheric growth rates of CO2 and N2O in 2008 are
consistent with recent years. The increase in atmospheric CH4 was 7 ppb from 2007 to
2008, similar to the increase of the year before. These are the largest increases
since 1998. From the existing data it is not clear if this 14 ppb increase over two
years represents the beginning of a new upward trend in CH4. The NOAA Annual
Greenhouse Gas Index (AGGI) shows that from 1990 to 2008 the radiative forcing by all
long-lived greenhouse gases has increased by 26.2%. The combined radiative forcing by
halocarbons is nearly double that of N2O. Some halocarbons are decreasing slowly as
a result of emission reductions under the Montreal Protocol on Substances That
Deplete the Ozone Layer, whereas others are increasing rapidly. GAW is supporting
the atmospheric component of the Integrated Global Carbon Observation System
that assesses routinely the state of the global carbon budget and is aimed at better
understanding atmospheric carbon sources and sinks through top-down inverse modelling. |
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