  Growth patterns of complex systems predict how they change in sizes, numbers,
masses, etc. Understanding growth is important, especially for many biological,
ecological, urban, and socioeconomic systems. One noteworthy growth behavior is
the 3/4- or and 2/3-power scaling law. It's observed in worldwide aquatic and
land biomass productions, eukaryote growth, mammalian brain sizes, and city
public facility distributions. Here, I show that these complex systems belong
to a new universality class whose system dimensionality determines its growth
scaling. The model uses producer-consumer dynamics to derive the n/(n+1) power
scaling law for an n-dimensional system. Its predictions are validated with
real-world two- and three-dimensional data. Dimensionality analysis thus
provides a new paradigm for understanding growth and growth-related problems in
a wide range of complex systems.
