Progress in Earth System Science: What Does It Take to Make Our Ideas Clear? - Towards an Interdisciplinary Approach in Earth System Science - page 26

Fig. 2 Different categories of earth system models: when the spatial and temporal resolution or
the number of earth system components increases, the required time and computing power also
increase. Earth system models of intermediate complexity (EMICs) could be low-order model
versions of a comprehensive model, or models with simplified physics parameterizing unresolved
spatial and temporal scales (Claussen et al. 2002 ). Conceptual models can be very low-
dimensional systems like the one displayed (Stommel 1961 ; Rooth 1982 ) and where sometimes
even the analytical solution is known (Lohmann and Schneider 1999 ), or statistical-conceptual
approaches
variables. The original idea stems from statistical physics for the description of
Brownian motion (Einstein 1905 ).
The effect of the weather on climate is seen by red-noise spectra in the climate
system, showing one of the most fundamental aspects of climate, and serving also
as a null hypothesis for climate variability studies (Frankignoul and Hasselmann
1977 ; Timmermann et al. 1998 ). Such hypothesis is required for our iterative
process in Fig. 1 . It can be of great utility to reduce the complexity of the system
being studied by using low-order, box, and conceptual models. This approach has
been successfully applied to a number of questions regarding feedback mechanisms
and the basic dynamical behavior of the Earth system. In some cases, such models
can provide a hypothesis for the dynamics of a complex system and make our ideas
clear. Such different hierarchies of models and independent results provide a dis-
tinction between an idea seeming clear and really being so (Peirce 1878 , 1974 ).