Isotropic simple global carbon model: The use of carbon isotopes for model development. Ph.D. Thesis

Thesis/Dissertation · Sat Jan 01 04:00:00 EST 1994

OSTI ID:218168

Kwon, O Y

Carbon dioxide is a major greenhouse gas in the atmosphere. Anthropogenic CO2 emissions from fossil fuel use and deforestation have perturbed the natural global carbon cycle. As a result, the atmospheric CO2 concentration has rapidly increased, causing the potential for global warming. A twenty four compartment isotopic simple global carbon model (IS-GCM) has been developed for scenario analysis, research needs prioritization, and for recommending strategies to stabilize the atmospheric CO2 level. CO2 fertilization and temperature effects are included in the terrestrial biosphere, and the ocean includes inorganic chemistry which, with ocean water circulation, enables the calculation of time-variable oceanic carbon uptake. The eight compartment simple global carbon model (SGCM) served as the basis of the ISGCM model development. Carbon isotopes, C-13 (stable carbon) and C-14(radiocarbon), were used for model constraints as well as results from SGCM that led to multiple compartments in ISGCM. The ISGCM was calibrated with the observed CO2 concentrations, delta C-13, and Delta C-14 in the atmosphere, Delta C-14 in the soil and Delta C-14 in the ocean. Also, ISGCM was constrained by literature values of oceanic carbon uptake (gas exchange) and CO2 emissions from deforestation. Inputs (forcing functions in the model) were the CO2 emissions from fossil fuel use and deforestation. Scenario analysis, together with emission strategies tests, indicate that urgent action to reduce anthropogenic emissions would need to be taken to stabilize atmospheric CO2. Results showed that quantitatively, forest management is just as effective as the reduction of fossil fuel emissions in controlling atmospheric CO2. Sensitivity analysis of temperature feedback suggests that future global warming would cause an additional perturbation in the global-carbon cycle, resulting in depletion of soil organic carbon, accumulation of plant biomass, and the increase of atmospheric CO2.

• Research Organization: Iowa Univ., Iowa City, IA (United States)
• OSTI ID: 218168
• Report Number(s): N--96-21395; NIPS--96-34654
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CARBON 13
CARBON 14
CARBON CYCLE
CARBON DIOXIDE
CLIMATIC CHANGE
COMPUTERIZED SIMULATION
GLOBAL ASPECTS
GREENHOUSE EFFECT
GREENHOUSE GASES