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 11, NUMBER 7, JULY 1998
"In Balance, with a Little Help from the Plants," P.P. Tans
(CMDL, NOAA, 325 S. Broadway, Boulder CO 80303; e-mail:
email@example.com), J.W.C. White,Science, 281(5374),
183-184, July 10, 1998.
A research perspective, summarizing the state of knowledge of the global
carbon cycle and key outstanding questions. A crucial test of hypotheses
and process models of the carbon cycle is the prediction of regional
"Testing Global Ocean Carbon Cycle Models Using Measurements of
Atmospheric O2 and CO2 Concentration," B.B.
Stephens (Scripps Inst. Oceanog., La Jolla CA 92093; e-mail:
firstname.lastname@example.org), R.F. Keeling et al., Global Biogeochem. Cycles,
12(2), 213-230, June 1998.
Defines a new quantity, atmospheric potential oxygen (O2 +
CO2), which is conservative with respect to terrestrial
photosynthesis and respiration. Uses this to evaluate simulations of the
global carbon cycle based on various global climate models.
"The Terrestrial Carbon Cycle: Implications for the Kyoto Protocol,"
IGBP Terrestrial Carbon Working Group (Roy. Swed. Acad. Sci., Box 50005,
S-10405, Stockholm, Swed.; Attn.: W. Steffen; e-mail: email@example.com),Science,
280(5368), 1393-1394, May 29, 1998.
Annex 1 countries of the Kyoto Protocol can meet their commitments in
part by increasing net carbon sequestration in terrestrial carbon sinks.
This article discusses a number of problems relating to the carbon budget
that will seriously limit the Protocol's effectiveness if not corrected.
Terrestrial carbon sinks can offset fossil fuel emissions only temporarily
(decades to a century), and are best viewed as buying valuable time to
address the most significant anthropogenic perturbation of the carbon
cyclefossil fuel emissions.
Three related items in Nature, 393(6682), May 21, 1998:
"The Carbon Equation," D.S. Schimel (NCAR, POB 3000, Boulder
CO 80307; e-mail: firstname.lastname@example.org), 208-209. Compares and contrasts
the following two studies, which taken together, bring a renewed sense of
urgency to research on the future behavior of the Earth system, especially
the coupling of anthropogenic greenhouse gases to the climate and carbon
"Dynamic Responses of Terrestrial Ecosystem Carbon Cycling to
Global Climate Change," M. Cao (Dept. Environ. Sci., Univ. Virginia,
Charlottesville VA 22903), F.I. Woodward, 249-252. Uses a terrestrial
biogeochemical model, forced by simulations of transient climate change
with a GCM, to quantify the dynamic variations in ecosystem carbon fluxes
caused by fluctuations in CO2 and climate from 1861 to 2070.
Predicts that the global net ecosystem production will increase
significantly, but this response will decline as the CO2
fertilization effect becomes saturated and is diminished by climatic
"Evaluation of Terrestrial Carbon Cycle Models Through Simulations of
the Seasonal Cycle of Atmospheric CO2: First Results of a
Model Intercomparison Study," M. Heimann (Max Planck Inst. Meteor.,
Bundesstr. 55, D-20146 Hamburg, Ger.; e-mail: email@example.com), G.
Esser et al., Global Biogeochem. Cycles, 12(1), 1-24, Mar.
Reports an extensive international comparison of models (one diagnostic
and five prognostic) that were run with the same long-term climate
forcing, and compared to observations collected at 27 NOAA monitoring
stations. Model performance generally differs between the tropics and the
"Missing Sinks, Feedbacks and Understanding the Role of Terrestrial
Ecosystems in the Global Carbon Balance," R.A. Houghton (Woods Hole
Res. Ctr., POB 296, Woods Hole MA 02543; e-mail: firstname.lastname@example.org), E.A.
Davidson, G.M. Woodwell,Global Biogeochem. Cycles, 12(1),
25-34, Mar. 1998.
Data pertaining to temporal variability in the global carbon balance are
conflicting with respect to the question of whether increasing
temperatures cause a release or storage of terrestrial carbon; the answer
seems to depend in part on time scale. However, a positive feedback
between temperature and the release of CO2 by terrestrial
respiration seems likely to grow in importance, and could change
significantly the role that terrestrial ecosystems play in the global
"Carbon Cycling in Cultivated Land and Its Global Significance,"
G.A. Buyanovsky (Soil & Atmos. Sci. Dept., 144 Mumford Hall, Univ.
Missouri, Columbia MO 65211), G.H. Wagner,Global Change Biology,
4(2), 131-141, Feb. 1998.
Long-term data from one of the oldest experimental fields in the U.S.
were used to determine the direction of soil organic carbon dynamics in
cultivated land. Results show that cultivated soils under proper
management exercise a positive influence in the current imbalance in the
global carbon budget.
"The Global Carbon Sink: A Grassland Perspective," J.M.O.
Scurlock (Environ. Sci. Div., Oak Ridge Natl. Lab., POB 2008, Oak Ridge TN
37831; e-mail: email@example.com), D.O. Hall,Global Change Biology,
4(2), 229-233, Feb. 1998.
The challenge to identify the biospheric sinks for about half the total
fossil fuel carbon emissions must consider below-ground processes as well
as those more easily measured above ground. The rapid increase in the
availability of productivity data facilitated by the Internet will be
important for future scaling-up of global change responses.
"Estimating the Terrestrial Carbon Pools of the Former Soviet Union,
Conterminous U.S., and Brazil," D.P. Turner (Dept. Forest Sci.,
Oregon State Univ., Corvallis OR 97331; e-mail: firstname.lastname@example.org),
J.K. Winjum et al.,Clim. Res., 9(3), 183-196, Feb. 27,
Estimates and contrasts the carbon pools in the three areas using
various sources of data. The two largest pools isolated are potentially
long-term sources of carbon to the atmosphere: peatland of the former
Soviet Union, which could release carbon under climate change; and
phytomass in the tropical-moist forests of Brazil, which may be lost via
"Reduced Sensitivity of Recent Tree-Growth to Temperature at High
Northern Latitudes," K.R. Briffa (Clim. Res. Unit, Univ. E. Anglia,
Norwich NR4 7TJ, UK; e-mail: email@example.com), F.H. Schweingruber et
al.,Nature, 391(6668), 678-682, Feb. 12, 1998.
Results indicate that estimates of future atmospheric CO2
concentrations, based on carbon-cycle models that are uniformly sensitive
to high-latitude warming, could be too low.
"Phytoplankton Change in the North Atlantic," P.C. Reid (Sir
Alister Hardy Foundation for Ocean Sci., The Laboratory, Citadel Hill,
Plymouth PL1 2PB, UK; e-mail: firstname.lastname@example.org), M. Edwards et al.,Nature,
391(6667), 546, Feb. 5, 1998.
Observations have implications for CO2 fluxes and the
productivity of the North Atlantic, and suggest the possible importance of
shelf phytoplankton growth to the global carbon budget.
"Net Primary and Ecosystem Production and Carbon Stocks of
Terrestrial Ecosystems and Their Responses to Climate Change," M. Cao
(Dept. Animal & Plant Sci., Univ. Sheffield, Sheffield S10 2TN, UK;
e-mail: email@example.com), F.I. Woodward,Global Change Biology,
4(2), 185-198, Feb. 1998.
Describes a model for investigating terrestrial carbon exchange and its
response to climatic variation, based on the processes of photosynthesis,
carbon allocation, litter production and soil organic carbon
decomposition. Predicts a strong enhancement in net primary production and
carbon stocks of terrestrial ecosystems.
"Sensitivity of Boreal Forest Carbon Balance to Soil Thaw," M.L.
Goulden (Dept. Earth. Sys. Sci., Univ. California, Irvine CA 92697;
e-mail: firstname.lastname@example.org), S.C. Wofsy et al.,Science, 279(5348),
214-217, Jan. 9, 1998.
Field and laboratory measurements show that decomposition of organic
matter in the soil increased 10-fold upon thawing. The stability of the
soil carbon pool appears sensitive to the depth and duration of thaw, and
climatic changes that promote thaw are likely to cause a net efflux of CO2
from the site.
"The Effects of Water Table Manipulation and Elevated Temperature on
the Net CO2 Flux of Wet Sedge Tundra Ecosystems," W.C.
Oechel (Global Change Res. Group, Dept. Biol., San Diego State Univ., San
Diego CA 92182; e-mail: email@example.com), G.L. Vourlitis et al.,
Global Change Biology, 4(1), 77-90, Jan. 1998.
Field experiments suggest that many currently saturated or nearly
saturated wet sedge ecosystems of the North slope of Alaska may become
significant sources of CO2 if climate change predictions are
realized. There is ample evidence that this may already be occurring in
"Carbon Budget Implications of the Transition from Natural to Managed
Disturbance Regimes in Forest Landscapes," W.A. Kurz (ESSA Technol.
Ltd., 1765 W. 8th Ave., Vancouver BC V6J 5C6, Can.; e-mail:
firstname.lastname@example.org), S.J. Beukema, M.J. Apps,Mitigation & Adaptation
Strategies for Global Change, 2(4), 405-421, 1997-1998.
Applies the Carbon Budget Model of the Canadian Forest Sector to six
representative landscapes undergoing transition from natural conditions to
harvesting. After 200 years of forest management, the carbon stored in the
landscape plus that retained in manufactured forest products was between
58% and 101% of the landscape carbon prior to the onset of harvesting.
"Terrestrial Carbon Dynamics: Case studies in the Former Soviet
Union, the Conterminous United States, Mexico and Brazil," M.A.
Cairns (U.S. EPA, 200 SW 35th St., Corvallis OR 97333; e-mail:
email@example.com), J.K. Winjum et al.,ibid., 1(4),
Assesses land-use impacts on carbon flux at a national level. Total flux
from land use was negative (corresponding to emissions) in all four
countries. The total net effect of biotic and land-use factors was a
carbon sink in the FSU and the U.S., and a source in both Mexico and
"The Response of Global Terrestrial Ecosystems to Interannual
Temperature Variability," B.H. Braswell (Inst. Study Earth, Oceans &
Space, Univ. New Hampshire, Durham NH 03824; e-mail:
firstname.lastname@example.org), D.S. Schimel et al.,Science, 278(5339),
870-872, Oct. 31, 1997.
Measurements of CO2 and satellite-derived measurements of
temperature and vegetation index were used to investigate relationships
among climate, CO2, and ecosystems. Results imply that changes
in global ecosystem distributions could indirectly alter the relationships
between climate and carbon storage.
"Simulating Effects of Fire on Gaseous Emissions and Atmospheric
Carbon Fluxes from Coniferous Forest Landscapes," R.E. Keane
(Intermountain Res. Sta., Fire Sci. Lab., USDA Forest Service, POB 8089,
Missoula MT 59807), C.C. Hardy et al.,World Resource Review, 9(2),
177-205, June 1997.
Uses a mechanistic forest succession model to examine long-term trends
in emissions of particles, methane, CO, and CO2 under current,
historical and future fire regimes in Glacier National Park. The model
indicates that temperate and sub-boreal coniferous forest landscapes with
fire tend to respire less carbon, even when carbon emissions from fire are
included. Discusses potential implications for wildland fire management
and the global carbon cycle.
"An Integrated Modeling Approach to Global Carbon and Nitrogen
Cycles: Balancing Their Budgets," M.G.J. den Elzen (Global Dynamics &
Sustainable Development, Natl. Inst. Public Health & Environ.-RIVM,
POB 1, NL-3720 BA Bilthoven, Neth.), A.H.W. Beusen, J. Rotmans,Global
Biogeochem. Cycles, 11(2), 191-215, June 1997.
Integrated but simple models of the coupled carbon-nitrogen cycle and
climate show that N fertilization feedback may be important for balancing
the past carbon budget, and that nutrient limitation can seriously limit
CO2 fertilization feedback. Both mechanisms should be examined
in more detailed carbon cycle models, and if the results are confirmed,
should be incorporated into IPCC projections.
"Boreal Forest Carbon Stocks and Wood Supply: Past, Present and
Future Responses to Changing Climate, Agriculture and Species
Availability," A.M. Solomon (U.S. EPA, 200 SW 35th St., Corvallis OR
97333), R. Leemans,Agric. & Forest Meteor., 84(1-2),
137-151, Mar. 1997.
Calculations were based on a standard static vegetation model driven by
the most recent climate change scenarios from three coupled
ocean-atmosphere models. The lag in immigration of tree species suitable
for a warmed climate temporarily reduced future wood supplies 4-6%;
inclusion of present and future agricultural land uses permitted by a
warming climate reduced carbon stocks and wood supplies 10-20%.
"Forest Plantations of the World: Their Extent, Ecological
Attributes, and Carbon Storage," J.K. Winjum (U.S. EPA, 200 SW 35th
St., Corvallis OR 97333), P.E. Schroeder,ibid., 153-167.
New plantations are established each year by 124 countries throughout
the high, middle, and low latitudes of the world. This study integrates
information across latitudes to estimate world carbon storage in
plantations to be 11.8 Pg C, with an annual increase of 0.178 Pg C per
"State and Change in Carbon Pools in the Forests of Tropical Africa,"
G. Gaston, S. Brown (U.S. EPA, 200 SW 35th St., Corvallis OR 97333;
e-mail: email@example.com) et al.,Global Change Biol.,
4(1), 97-114, Jan. 1998.
Combines spatially explicit estimates of biomass C density, obtained by
modeling in a geographical information system, with new data on the area
of forests reported for 1980 and 1990 by the FAO. Estimates the total
change in above-ground forest C pool for the decade 1980-1990, due to
changes in land cover use, to be a decrease of 6.6Pg C. Of this, 43% was
due to deforestation and 57% due to biomass reduction by other human
"Principles for a Climate Regulation Mechanism during the Late
Phenerozoic Era, Based on Carbon Fixation in Peat-Forming Wetlands,"
L.G. Franzén (Dept. Phys. Geog., Göteborg Univ., S-413 81
Gothenburg, Sweden; e-mail: LARS@gig.gu.se), D. Chen, L.F. Klinger,Ambio,
25(7), 435-442, Nov. 1996.
Models the climate regulating effect of peat bogs, which act as carbon
sinks. With present levels of CO2, the model shows that the
initiation of a new ice age could already have been delayed roughly
700-1000 years. Scenarios with further increases in CO2 show a
much longer delay.
"Atmospheric Gas Concentrations over the Past Century Measured in Air
from Firn at the South Pole," M. Battle (Grad. Sch. Oceanog., Univ.
Rhode Island, Naragansett RI 02882), M. Bender et al.,Nature, 383(6597),
231-235, Sep. 19, 1996.
Results show that, in contrast to the past few years, the terrestrial
biosphere was neither a source nor a sink of CO2 between about
1977 and 1985.
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