 |
| Titel |
What we learn from updates of NOAA's Annual Greenhouse Gas Index (AGGI) |
| VerfasserIn |
James H. Butler, Stephen A. Montzka, Edward Dlugokencky, James W. Elkins, Kenneth Masarie, Russell C. Schnell, Pieter Tans, Geoff Dutton, Ben R. Miller |
| Konferenz |
EGU General Assembly 2014
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250094522
|
| Publikation (Nr.) |
 EGU/EGU2014-9936.pdf |
|
|
|
|
|
| Zusammenfassung |
| Several years ago, NOAA introduced a unique index for expressing the influence of
human-emitted, long-lived greenhouse gases in the atmosphere (D.J. Hofmann et al., Tellus,
2006, S8B, 614-619). Being a condensation and normalization of radiative forcing from
long-lived gases, the NOAA Annual Greenhouse Gas Index (AGGI) was designed to enhance
the connection between scientists and society by providing a standard that could be easily
understood and followed. The index each year is calculated from high quality, long-term
observations by NOAA’s Global Monitoring Division, which includes real-time
measurements extending over the past five decades, as well as published ice core
records that go back to 1750. The AGGI is radiative forcing from these long-lived
gases, normalized to 1.00 in 1990, the Kyoto Climate Protocol baseline year. For
2012, the AGGI was 1.32, indicating that global radiative forcing by long-lived
greenhouse gases had increased 32% since 1990. During the 1980s CO2 accounted
for about 50-60% of the annual increase in radiative forcing (and the AGGI) by
long-lived greenhouse gases, whereas, since 2000, it has accounted for 80-90% of this
increase each year. After nearly a decade of virtually level concentrations in the
atmosphere, methane (CH4) has increased measurably over the past 6 years, as did its
contribution to radiative forcing (and the AGGI). This year, in addition to updating the
AGGI for 2013, increases in radiative forcing will be evaluated and discussed with
respect to time-dependent changes in the contributions from CO2, CH4, nitrous
oxide (N2O), chlorofluorocarbons (CFCs), and other emerging greenhouse gases. |
|
|
|
|
|
|