The development of flicker noise (1/f noise) in dynamical systems with extended spatial degrees of freedom is investigated analytically. A natural evolution of self-organized critical structures of states which are barely stable is demonstrated, and the results of numerical simulations are presented graphically. The implications of the present analytical approach for phenomena related to 1/f noise (such as the self-similar fractal structure of spatially extended objects and the development of turbulence) are discussed.