The classical theory of 2d and quasi-geostrophic turbulence deals withhighly idealized systems and predicts inverse energy cascade towardlarge scales and also spectral laws for the eddy kinetic energy. Itturns out that the real world systems like the atmosphere and oceanare following these predictions only very approximately.The talk touches briefly the basic issues of the theory andexplains them from a physical viewpoint. These will include the notionof the inverse cascade, formation of jets and the Rhines scale, andinteraction between barotropic/baroclinic modes in quasigeostrophicflows. They will be compared to the observations available in theatmosphere and in the ocean.The basic conclusion is that the idea of the inverse energy cascade inbarotropic mode is supported, yet cascades in the original sense arenever observed as energy generation and energy dissipation occur overapproximately same intervals of wavenumbers.