February 28, 2007
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Global Climate Change Digest
A Guide to Information on Greenhouse Gases and Ozone Depletion
Published July 1988 through June 1999
FROM VOLUME 7, NUMBER 9, SEPTEMBER 1994
PROFESSIONAL PUBLICATIONS... OF GENERAL INTEREST: CLIMATE CHANGE SCIENCE
"Recent and Future Climate Change in East Asia," M.
Hulme (Clim. Res. Unit, Univ. E. Anglia, Norwich NR4 7TJ, UK),
Z.-C. Zhao, T. Jiang, Intl. J. Climatol., 14(6),
637-658, July 1994.
Examines climate change over the past 100 years (from
instrument records) and projects it over the next 100 years
(using results from climate model experiments). The region has
undoubtedly warmed over the last century; the substantial role of
urbanization cannot account for all the temperature change.
Illustrates a flexible composite-model approach to regional
climate change scenario construction which can explicitly
incorporate the effects of model uncertainty. The scenario
presented suggests that by 2050, mean conditions are expected to
be warmer than the extremely warm seasonal anomalies of the most
related items in Nature, 371(6493), Sep. 8, 1994:
"Testing the Iron Hypothesis in Ecosystems of the
Equatorial Pacific Ocean," J.H. Martin, K.H. Coale (Moss
Landing Marine Labs., POB 450, Moss Landing CA 95039), et al.,
123-129. The idea that iron may limit phytoplankton growth in
large regions of the ocean was tested by enriching with iron an
area of 64 km2 in the open equatorial Pacific. Plant biomass
doubled and plant production increased fourfold, indicating that
iron can control rates of phytoplankton productivity in the
ocean. The experiment was intended to explore ecosystem function
and was not intended as a preliminary step to climate
manipulation. It also demonstrated the feasibility of open-ocean
manipulative experiments, which may signal the beginning of a new
era in geochemical and ecological studies.
"Minimal Effect of Iron Fertilization on Sea-Surface
Carbon Dioxide Concentrations," A.J. Watson (Plymouth Marine
Lab., Prospect Pl., West Hoe, Plymouth PL1 3DH, UK), C.S. Law et
al., 143-145. The possibility that iron limits phytoplankton
productivity has led to the suggestion that iron may have played
a role in modulating atmospheric CO2 levels between glacial and
interglacial times. CO2 concentrations in the experiment
described showed less of an effect than has been observed in
incubation experiments, and does not support the idea that iron
fertilization would significantly affect atmospheric CO2
"Iron Limitation of Phytoplankton Photosynthesis in the
Equatorial Pacific Ocean," Z.S. Kolber (Oceanog. &
Atmos. Sci. Div., Brookhaven Natl. Lab, Upton NY 11973), R.T.
Barber et al., 145-149. Changes in the photochemical energy
conversion efficiency of the natural phytoplankton community were
followed before and after artificial enrichment with iron in the
open ocean. Results show that iron limits photosynthesis in all
size classes by impairing intrinsic photochemical energy
conversion, supporting the hypothesis of physiological
("bottom up") limitation by iron, rather than "top
down" grazing pressure by herbivores, a mechanism that has
also been proposed.
related items in Nature, 370(6489), Aug. 11, 1994:
"Dirty Clouds and Global Cooling," G.L. Stephens
(Dept. Atmos. Sci., Colorado State Univ., Ft. Collins CO 80523),
420-421. Offers a research perspective on the following paper.
"A Climate Model Study of Indirect Radiative Forcing by
Anthropogenic Sulphate Aerosols," A. Jones (Hadley Ctr.,
Meteor. Off., London Rd., Bracknell, Berkshire RG12 2SY, UK),
450-453. The direct effect of aerosols has been estimated
to be a significant fraction of the radiative influence of
greenhouse gases, but their indirect effect, through the
alteration of radiative characteristics of clouds, is much more
difficult to assess. A 3-D chemical transport model and a GCM
indicate that the indirect cooling effect of aerosols is about
half the warming effect of greenhouse gases in the global annual
mean. Although this estimate is subject to considerable
uncertainty, it exceeds many estimates of the direct effect,
indicating the potential importance of the indirect effect of
anthropogenic aerosols in climate change.
related items in Nature, 370(6489), Aug. 11, 1994:
"Cooler Estimates of Cretaceous Temperatures," B.W.
Sellwood (Postgrad. Inst. Sedimentol., Univ. Whiteknights,
Reading RG6 2AB, UK), G.D. Price, P.J. Valdes, 453-455. The high
temperatures and CO2 levels of the Cretaceous period suggest that
this time period could be used by modelers as an analog for
future climate change. However, new records of ocean
paleotemperature cast doubt on the idea that the Cretaceous was
generally warmer, making the climatic role of atmospheric CO2
unclear and suggesting that the Cretaceous cannot be used as an
analog for the future.
"Chill over the Cretaceous," E.J. Barron (Earth
Systems Sci. Ctr., Pennsylvania State Univ., 248 Deike Bldg.,
Univ. Pk. PA 16802), 415. Comments on previous paper. The large
number of differences between past and present climatic periods
make it unlikely that any past climate can be a true analog for
"Global Decrease in Atmospheric Carbon Monoxide
Concentration," M.A.K. Khalil (Global Change Res. Ctr.,
Oregon Graduate Inst., Beaverton OR 97006), R.A. Rasmussen, Nature, 370(6491),
639-641, Aug. 25, 1994.
During the 1980s there was evidence that atmospheric CO
concentrations were increasing at about 1.2% per year, leading to
feedbacks that could amplify global warming. A continuation of
those measurements shows that from 1988 to 1992 global CO
concentrations have been declining rapidly at about 2.6% per
year. A decreasing trend in tropical biomass burning is a
"Evidence of a Long-Term Increase in Tropospheric Ozone from
Pic du Midi Data Series: Consequences: Positive Radiative
Forcing," A. Marenco (Lab. d'A?rologie, CNRS-URA 0354,
Univ. P. Sabatier, 31062 Toulouse Cedex, France), H. Gouget et
al., J. Geophys. Res., 99(D8), 16,617-16,632, Aug.
Old ozone measurements recently discovered at the Pic du Midi
Observatory (altitude 3000 m, southwestern France) were used to
complete a time series covering 1874 to 1993. Ozone has increased
by a factor of five since the beginning of this century. For the
first two decades of the period, the mixing ratio was stable at
10 ppb, representing the preindustrial era. A tentative
evaluation of radiative forcing confirms that ozone is currently
the second most significant greenhouse gas, accounting for 22% of
the radiative forcing changes in the Northern Hemisphere since
"Modeling the Global Carbon Cycle: Nitrogen Fertilization of
the Terrestrial Biosphere and the 'Missing' CO2 Link,"
R.J.M. Hudson (Inst. Marine Sci., Univ. California, Santa Cruz CA
95064), S.A. Gherini, R.A. Goldstein, Global Biogeochem.
Cycles, 8(3), 307-333, Sep. 1994.
Describes and applies GLOCO, a global carbon cycle model with
relatively detailed treatment of oceanic and terrestrial
processes and anthropogenic activities. Confirms previous
suggestions that because temperate and boreal forests are
nitrogen limited, CO2 fertilization is less than predicted by
short-term CO2 response factors. Fertilization by anthropogenic
nitrogen emissions probably constitutes a significant portion of
the "missing" CO2 sink.
"Effects of Reductions in Stratospheric Ozone on
Tropospheric Chemistry Through Changes in Photolysis Rates,"
J.S. Fuglestvedt (Ctr. Intl. Clim. & Energy Res.--Oslo
(CICERO), Univ. Oslo, POB 1129 Blindern, 0317 Oslo, Norway), J.E.
Jonson, I.S.A. Isaksen, Tellus, 46B(3), 172-192,
Calculates effects of changes in UV radiation due to
stratospheric ozone depletion for selected years from 1970 to
2050. Tropospheric ozone is reduced in most areas, but at
a smaller percentage than the UV increase. Increased UV may have
contributed about one third the reduction in the growth rate of
methane, thus partially offsetting the climate change effect of
ozone depleting substances.
Level," C. Woodroffe (Dept. Geog., Univ. Wollongong, New
South Wales 2522, Australia), Prog. Phys. Geog., 18(3),
436-451, Sep. 1994.
Reviews recent efforts to reconstruct or explain the past
pattern of truly global (eustatic) sea level change over the Late
Quaternary, and reviews attempts to monitor current sea level
Atlantic Climate Change Program," R.L. Molinari (Atlantic
Oceanog. Lab., NOAA, 4301 Rickenbacker Causeway, Miami FL 33149),
D. Battisti et al., Bull. Amer. Meteor. Soc., 75(7),
1191-1199, July 1994.
Gives a detailed overview of this component of NOAA's Climate
and Global Change Program, which is directed at determining the
role of the thermohaline circulation of the Atlantic Ocean on
global atmospheric climate.
Guide to Publishers
Index of Abbreviations