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| Titel |
The state of greenhouse gases in the atmosphere using global observations through 2009 |
| VerfasserIn |
Oksana A. Tarasova, Kazuto Suda, Edward Dlugokencky, Doug Worthy, Tuomas Laurila, Sander Houweling, Jim Butler |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250050828
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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
atmospheric composition, including greenhouse gases. 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
more than 100 stations worldwide for the key greenhouse gases (CO2 and CH4)
and at a smaller number of stations for the other greenhouse gases. The results
of the latest analysis are presented in the WMO/GAW Greenhouse Gas Bulletin
published in November 2010. The globally averaged mixing ratios of carbon dioxide
(CO2), methane (CH4) and nitrous oxide (N2O) reached new highs in 2009, with
CO2 at 386.8 ppm, CH4 at 1803 ppb and N2O at 322.5 ppb. These values are
greater than those in pre-industrial times (before 1750) by 38%, 158% and 19%,
respectively. Atmospheric growth rate of CO2 in 2009 was 1.6 ppm, which is higher
than the average for the 1990s (~ 1.5 ppm/yr), but lower than the average for the
past decade. The growth rate of N2O in 2009 was 0.6 ppb which is also less than
the one averaged over the last 10 years (0.77 ppb/yr). Both grow rate deviations
from the 10 years averaged are due to natural interannual variability. After nearly a
decade of no growth, atmospheric CH4 has increased during the past three years. The
reasons for renewed growth of atmospheric methane are not fully understood, but
emissions from natural sources (from northern latitudes and the tropics) are considered
potential causes. The NOAA Annual Greenhouse Gas Index (AGGI) shows that
from 1990 to 2009, radiative forcing by all long-lived greenhouse gases increased
by 27.5%, with CO2 accounting for nearly 80% of this increase. The combined
radiative forcing by halocarbons is nearly double that of N2O. 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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