Climate models are quantitative methods used to interactions of atmosphere ,ocean,landsurface and sea ice.they are used to project future climate.
The most talked about models are those relating temperature to O2 emission.these models have projected an upward trend in the surface temperature at higher altitude .Similarly,they have projected a substantial decrease in arctic sea ice thickness.
recently-3d GCM model has been developed which works on the following principle.
-simulate the earth's atmosphere mathematically by covering the earth surface with 0-64 stacked layers of giggantic cell (3 k.m)
-assign an initialvalue for each variable to each box. these variables include temperature,pressure,wind speed and direction,concenteration of key chemicals CO2 and H2O vapour.
-Develop a set of equations describing the expected flow of energy and matter in and out of the box filled atmosphere.the input called boundary conditions includes variables such as solar radiation,precipitation,cloudiness,interactions between atmosphere and ocean aswell as air pollutants.
-Develpo an elaborate set of mathematical equations that connect the cellso that when the value of any of these input variables undergo changes in one cell.The value of variables in surrounding cell undergoes change in realistic way.
-run the model on a copmputer ti simulate change in average global temperature and climate change in the part (to verify the model) and project future change.
