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| Titel |
The state of greenhouse gases in the atmosphere using global observations through 2015 |
| VerfasserIn |
Oksana Tarasova, Alex Vermeulen, Mikio Ueno |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250144941
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| Publikation (Nr.) |
 EGU/EGU2017-8824.pdf |
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| Zusammenfassung |
| We present results from the twelfth annual Greenhouse Gas Bulletin
(http://www.wmo.int/pages/prog/arep/gaw/ghg/GHGbulletin.html) of the World
Meteorological Organization (WMO). The results are based on research and observations
performed by laboratories contributing to the WMO Global Atmosphere Watch (GAW)
Programme (www.wmo.int/gaw).
The Bulletin presents results of global analyses of observational data collected according
to GAW recommended practices and submitted to the World Data Center for Greenhouse
Gases (WDCGG). Bulletins are prepared by the WMO/GAW Scientific Advisory Group for
Greenhouse Gases (http://www.wmo.int/pages/prog/arep/gaw/ScientificAdvisoryGroups.html) in
collaboration with WDCGG.
Observations used for global analysis are collected at more than 100 marine and
terrestrial sites worldwide for CO2 and CH4 and at a smaller number of sites for other
greenhouse gases. Globally averaged dry-air mole fractions of carbon dioxide, methane and
nitrous oxide derived from this network reached new highs in 2015, with CO2 at
400.0±0.1 ppm, CH4 at 1845±2 ppb and N2O at 328.0±0.1 ppb. These values constitute
144%, 256% and 121% of pre-industrial (before 1750) levels, respectively. It is
predicted that 2016 will be the first year in which CO2 at the Mauna Loa Observatory
remains above 400 ppm all year, and hence for many generations ( Betts et al.,
2016).
The atmospheric increase of CO2 from 2014 to 2015 was 2.3 ppm, which is
larger than the increase from 2013 to 2014 and the average growth rate for the past
decade (∼2.08 ppm per year), despite evidence that global anthropogenic emissions
remained essentially static between 2014 and 2015. The higher growth rate in 2015
compared with the previous years is due to increased natural emissions of CO2 related
to the most recent El Niño event. According to the most recent data, increased
growth rates have persisted far into 2016, consistent with the expected lag between
CO2 growth and the ENSO index. The average increase in atmospheric CO2 from
2005 to 2014 corresponds to ∼44% of the CO2 emitted by human activity with the
remaining ∼56% removed by the oceans and the terrestrial biosphere (La Quéré et al.,
2015).
For CH4 the increase from 2014 to 2015 was larger than that observed from 2013 to 2014
and the mean growth rate over the past 10 years. The annual increase of N2O globally
averaged mole fraction from 2014 to 2015 was similar to that observed from 2013 to 2014
and greater than the average growth rate over the past 10 years. The National Oceanic and
Atmospheric Administration (NOAA) Annual Greenhouse Gas Index shows that from 1990
to 2015 radiative forcing by long-lived greenhouse gases increased by 37%, with CO2
accounting for about 80% of this increase. The radiative forcing by all long-lived
greenhouse gases in 2015 corresponded to a CO2-equivalent mole fraction of 485 ppm
(http://www.esrl.noaa.gov/gmd/aggi).
Bulletin cover story explains the connection between CO2 growth rates and
El Niño phenomena. Bulletin contains brief introduction of the Integrated Global
Greenhouse Gas Information System, which will be presented separately at the other
session.
References
Betts, R.A. et al, 2016: El Niño and a record CO2 rise. Nature Climate Change,
6(9):806–810, doi:10.1038/nclimate3063.
Le Quéré, C. et al. 2015: Global carbon budget 2015. Earth System Science Data,
7(2):349–396, doi:10.5194/essd-7-349-2015. |
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