Climate model simulations of the equilibrium climatic response to increased carbon dioxide
The first assessments of the potential climatic effects of increased CO/sub 2/ were performed using simplified climate models, namely, energy balance models (EBMs) and radiative-convective models (RCMs). The feedback processes in RCMs include water vapor feedback, moist adiabatic lapse rate feedback, cloud altitude feedback, cloud cover feedback, cloud optical depth feedback, and surface albedo feedback. However, these feedbacks can be predicted credibly only by physically based models that include the essential dynamics and thermodynamics of the feedback processes. Such physically based models are the general circulation models (GCMs). The earliest GCM simulations of CO/sub 2/-induced climate change were performed without the annual insolation cycle. The first GCM simulation of the seasonal variation of CO/sub 2/-induced climate change was performed for a CO/sub 2/ quadrupling and obtained annual global mean surface temperature and precipitation changes of 4.1/sup 0/C and 6.7%, respectively. Recently, three CO/sub 2/-doubling experiments have been performed with GCMs that include the annual insolation cycle. These seasonal simulations give an annual global mean warming of 3.5/sup 0/ to 4.2/sup 0/C and precipitation increases of 7.1 to 11%. The geographical distributions of the CO/sub 2/-induced warming obtained by the recent simulations agree qualitatively but not quantitatively. Furthermore, the precipitation and soil moisture changes do not agree quantitatively and even show qualitative differences. In order to improve the state of the art in simulating the equilibrium climatic change induced by increased CO/sub 2/ concentrations, it is recommended first that the contemporary GCM simulations be analyzed to determine the feedback processes responsible for their differences and second that the parameterization of these processes in the GCMs be validated against highly detailed models and observations.
- Research Organization:
- Oregon State Univ., Corvallis (USA)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 6871280
- Journal Information:
- Rev. Geophys.; (United States), Vol. 25:4
- Country of Publication:
- United States
- Language:
- English
Similar Records
Climate data, analysis and models for the study of natural variability and anthropogenic change
Cloud feedback mechanisms and their representation in global climate models
Related Subjects
CARBON DIOXIDE
ECOLOGICAL CONCENTRATION
ENVIRONMENTAL EFFECTS
CLIMATES
VARIATIONS
GREENHOUSE EFFECT
CLIMATE MODELS
GENERAL CIRCULATION MODELS
AMBIENT TEMPERATURE
ATMOSPHERIC PRECIPITATIONS
ENERGY BALANCE
REVIEWS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
DOCUMENT TYPES
MATHEMATICAL MODELS
OXIDES
OXYGEN COMPOUNDS
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)