Spatial analogues have also been exploited
along altitudinal gradients to project vegetation composition, snow conditions for skiing, and avalanche risk (e.g., Beniston and Price, 1992; Holten and Carey, 1992; Gyalistras et al., 1997).
Since we can not measure any individual forcing directly in the atmosphere, the models draw upon results of laboratory experiments in passing sunlight through chambers in which atmospheric constituents are artificially varied; such experiments are, however, of limited value when translated into the real atmosphere, where radiative transfers and non-radiative transports (convection and evaporation up, advection
along, subsidence and precipitation down), as well as
altitudinal and latitudinal asymmetries, greatly complicate the picture.