February 28, 2007
GCRIO Program Overview
Our extensive collection of documents.
Archives of the
Global Climate Change Digest
A Guide to Information on Greenhouse Gases and Ozone Depletion
Published July 1988 through June 1999
FROM VOLUME 9, NUMBER 4, APRIL 1996
OF GENERAL INTEREST
Three related items in
Nature, 380(6573), Apr. 4, 1996:
"Raising Dust in the Greenhouse," M.O. Andreae (Dept. Biogeochem.,
M. Planck Inst. Chem., POB 3060, D-55020 Mainz, Ger.), 389-390. Discusses the
following two papers, which demonstrate that the amount of dust in the
atmosphere is increasing, largely because of human activity. Its climatic
importance is becoming clear, and heightens rather than reduces our concern
about anthropogenic climate change. Badly needed is an observational system that
will allow scientists 30 years from now to assess whether aerosol burdens have
"Dominance of Mineral Dust in Aerosol Light-Scattering in the North
Atlantic Trade Winds," X. Li (Sch. Marine & Atmos. Sci., Univ. Miami,
4600 Rickenbacker Causeway, Miami FL 33149), H. Maring et al., 416-419. Recent
studies of the effect of dust on climate have focused on anthropogenic sulfate
aerosols and have largely ignored mineral dust. Measurements reported here show
that the net scattering of light by North African mineral dust delivered to
Barbados by the trade winds is about four times that by non-seasalt sulfate
aerosols. Mineral dust could be an important climate forcing agent over this
ocean region and others. Although a natural substance, emissions of dust are
increasing, in part from human activity.
"The Influence of Climate Forcing of Mineral Aerosols from Disturbed
Soils," I. Tegen (Dept. Applied Phys., Columbia Univ., 2880 Broadway, New
York NY 10025), A.A. Lacis, I. Fung, 419-422. Previous work has shown that a
large fraction of tropospheric aerosol consists of wind-blown mineral dust
originating from soils disturbed by human activity or by drought or rain. This
study uses a radiative transfer model embedded in a general circulation model to
show that dust from disturbed soils causes a decrease of the net surface
radiation forcing of about 1 W m-2, accompanied by increased atmospheric heating
that may be a significant forcing of atmospheric dynamics.
Surprises," J.T. Overpeck (Paleoclim. Prog., NGDC, NOAA, 325 Broadway,
Boulder CO 80303), Science, 271(5257), 1820-1821, Mar. 29, 1996.
Reviews growing paleoclimatic evidence that, even in the absence of human
forcing, warm interglacial climates (such as the present Holocene) are capable
of generating significant decade- to century-scale climatic surprises, which may
be our biggest worry in the years to come. We are beginning to be able to map
the patterns of these variations, but unraveling their causes remains a major
challenge. If the climate system also turns out to be highly sensitive to
elevated trace gas concentrations, we may be confronted with modes of climate
variability without precedent.
Detection and Attribution of an Anthropogenic Effect on Climate," B.D.
Santer (Clim. Model Diagnosis Prog., Lawrence-Livermore Natl. Lab., POB 808,
Livermore CA 94550), K.E. Taylor et al., Clim. Dynamics,
12(2), 77-100, Dec. 1995.
Describes a further contribution toward distinguishing the climatic effects
of sulfate particles from those of greenhouse gases. Recent progress on this
topic was first announced at the Berlin climate treaty meeting last spring, and
was a major factor in the latest IPCC assessment of the science of climate
change. [See Global Climate Change Digest, Sep. 1995 for related paper
by Mitchell et al. (Prof. Pubs./of General Interest/Clouds and aerosols), and
related news note]. Results of model experiments in which sulfate and CO2
were varied individually and in combination were analyzed using pattern
similarity statistics, and compared with observed changes in patterns of surface
temperature change. Provides the first evidence that both large scale (global
mean) and smaller scale components of a combined CO2/anthropogenic
sulfate aerosol signal are identifiable in the temperature record.
contributions to the New Directions section of Atmos. Environ., 30,
1996. The first is a scientific perspective; the other two give contrasting
views representative of the regulatory authorities and agricultural users.
(Contributions to New Directions, under 1000 words, should be sent
electronically to NEW.DIRECTIONS@UEA.AC.UK. Contact W. Sturges at tel: 44 1603
592018; e-mail: W.STRUGES@UEA.AC.UK; or A. Lefohn at tel: 406 443 3389; e-mail:
"Scientific Uncertainties in the Budget of Atmospheric Methyl Bromide,"
J.H. Butler (CMDL, NOAA 325 Broadway, Boulder CO 80303), 30(7), ii-iii.
"Methyl BromidePesticide and Environmental Threat," W.
Thomas (Methyl Bromide Prog., Stratospheric Protection Div., US EPA, 401 M St.
SW, Washington, D.C.), 30(8), i-ii.
"Do We Need Further Controls of Agricultural Methyl Bromide?" T.
Duafala (Methyl Bromide Global Coalition, POB 1327, Hollister CA 95204), iii-iv,
Guide to Publishers
Index of Abbreviations