[Personnel: Last_Name='LIEF', Middle_Name='J.', First_Name='CHRISTINA']
NOAA ESRL Annual Green House Gas Index (AGGI)Entry ID: NOAA_ESRL_Annual_Green_House_Gas_Index_AGGI
Abstract: THE NOAA ANNUAL GREENHOUSE GAS INDEX (AGGI)
NOAA Earth System Research Laboratory, R/GMD, 325 Broadway, Boulder, CO 80305-3328
Updated September 10, 2010
Increases in atmospheric greenhouse gas abundances since the industrial revolution are largely responsible for the observed change in climate [IPCC2007]. However, climate projections have model ... uncertainties that overwhelm the uncertainties in greenhouse gas measurements. We present here an index that is directly proportional to the direct forcing of climate, but contains relatively small uncertainty.
The Intergovernmental Panel on Climate Change (IPCC) defines climate forcing as “An externally imposed perturbation in the radiative energy budget of the Earth climate system, e.g. through changes in solar radiation, changes in the Earth albedo, or changes in atmospheric gases and aerosol particles.” Thus climate forcing is a “change” in the status quo. IPCC takes the pre-industrial era (arbitrarily chosen as the year 1750) as the baseline. The perturbation to direct radiative climate forcing that has the largest magnitude and the least scientific uncertainty is the forcing related to changes in long-lived and well mixed greenhouse gases, in particular carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and halogenated compounds (mainly CFCs).
Atmospheric global greenhouse gas abundances are used to calculate changes in radiative forcing for the period beginning in 1979 when NOAA's global air sampling network expanded significantly. The change in annual average total radiative forcing by all the long-lived greenhouse gases since the pre-industrial era (1750) is used to define the NOAA Annual Greenhouse Gas Index (AGGI), which was introduced in 2004 [Hofmann et al., 2006a] and has been updated annually since.
The AGGI is a measure of radiative forcing of climate which was designed to enhance the connection between scientists and society by providing a normalized standard that can be easily understood and followed. The contribution of long-lived greenhouse gases to climate forcing is well understood by scientists and has been reported by NOAA through a range of national and international assessments. Nevertheless, the language of scientists often eludes policy makers, educators, and the general public. This index is designed to help bridge that gap. (from: http://www.esrl.noaa.gov/gmd/aggi/)
Start Date: 1979-01-01Stop Date: 2009-12-31
Role: DIF AUTHOR
Phone: +1 (828) 271-4101
Email: christina.lief at noaa.gov
Program Manager Global Observing Systems Information Center (GOSIC) NOAA/NESDIS/NCDC - Room 459
City: Asheville, NC
Province or State: NC
Postal Code: 28801
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Creation and Review Dates
DIF Creation Date: 2011-08-23
Last DIF Revision Date: 2011-08-31