Simulation of land-use patterns affecting the global carbon cycle. [Reconstruction and projection of CO/sub 2/ scenarios from 1860 to 2460]

Technical Report · Mon Jan 01 04:00:00 EST 1979

DOI:https://doi.org/10.2172/6206754· OSTI ID:6206754

Chan, Y. H.; Olson, J. S.; Emanuel, W. R.

Past increase of atmospheric CO/sub 2/ involves significant ntributions from both fossil and nonfossil (biospheric) sources. A simulation model was used to reconstruct changes since 1860 and project four hypothetical future scenarios of CO/sub 2/ injection to 2460. Nineteen compartments and their exchanges of carbon were considered. Areal extent of tropical forests, other wooded ecosystems, and nonforests were incorporated into the model. Rapidly and slowly exchanging pools of carbon per unit area, and net primary production for each pool and exosystem group, were projected by integrating income-loss differential equations numerically using CSMP programming language. Estimated cumulative releases of CO/sub 2/ from fossil fuels (plus cement) near 120 Gtons of carbon (1 Gton = 10/sup 9/ metric tons) from 1860 to 1970 were assumed to equal prompt and delayed releases from forest clearing. Limits of exploitable forest area and biomass were evaluated and found to contribute much less future CO/sub 2/ than the usable coal, oil, gas, and oil shale. Ultimate release from the latter (7500 +- 2500 x 10/sup 9/ tons of C) could increase atmospheric CO/sub 2/ manyfold: doubling the assumed 1860 levels as early as (1) year 2025 for assumed nominal scenario (expanding releases slightly less rapidly than at present), (2) year 2033 for a delayed expansion scenario that would prolong use of fossil reserves (lowering peak carbon release rate from approx. 43 to approx. 28 Gtons/year), (3) year 2087 for a slow burner scenario (increasing very slowly from present levels), and (4) year 2290 for a combination scenario (which assumes low fossil-fuel use, high carbon storage, and high net primary production of forested exosystems).

• Research Organization: Oak Ridge National Lab., TN (USA)
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6206754
• Report Number(s): ORNL/TM-6651
• Country of Publication: United States
• Language: English

Related Subjects

29 ENERGY PLANNING, POLICY, AND ECONOMY
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54 ENVIRONMENTAL SCIENCES
AIR POLLUTION
BIOSPHERE
CARBON
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CHALCOGENIDES
EARTH ATMOSPHERE
ECOSYSTEMS
ELEMENTS
ENERGY SOURCES
ENVIRONMENT
FORECASTING
FORESTS
FOSSIL FUELS
FUELS
MATHEMATICAL MODELS
MINERAL CYCLING
NONMETALS
OXIDES
OXYGEN COMPOUNDS
POLLUTION
SIMULATION
TERRESTRIAL ECOSYSTEMS