A new century/millennium provides an opportune time to reflect on how the science of ecology evolved during the 19th and 20th centuries, and to predict how it is likely to change during the 21st century (at least to reflect on how it might evolve in order to best serve societies during the decades ahead). This viewpoint article will attempt to: (a) provide an overview regarding the emergence of ecology from a subdiscipline of biology to a discipline of its own during the past century (Odum 1977); (b) discuss the academic fragmentation of ecology into numerous subdisciplines of study; and (c) argue that a new field of transdisciplinary science is urgently needed that will not only integrate these emerging fields of the ecological sciences, but will interface with the humanities and the social sciences as well (i.e., similar to C. P. Snow’s “third culture,” Snow 1963). Earlier we termed this 21st century field of study “integrative science” (Barrett & Odum 1998; Barrett & Kress 2001).