Carrying capacity, the number of individuals an environment can support without degrading, sits at the core of much of Colcom Foundation’s public education work. The concept applies to every species, including humans, and the Foundation argues that Earth’s ecosystems have finite limits for supporting human populations while still leaving room for other species to survive.

Colcom Foundation cites research by Rees from 2023 finding that global population growth accounted for roughly 80 percent of the increase in humanity’s total ecological footprint between 1961 and 2016, beyond what income and consumption growth alone would explain. That figure anchors much of the Foundation’s messaging on why population size deserves attention alongside lifestyle and technology.

Lessons From Rural Europe

European case studies feature prominently in this work. Deinet et al. documented a 28 percent decline in rural populations across Europe between 1960 and 2010, a shift that coincided with the recovery of numerous mammal and bird species. Chapron et al. found that as rural populations fell, large carnivores including wolves, bears, and lynx naturally returned to former agricultural land, a pattern the Colcom Foundation treats as evidence that reduced human density can support rewilding.

Applying the Concept Broadly

Colcom Foundation funds analysis of biocapacity consumption and resource depletion rates alongside its carrying capacity education, drawing on Global Footprint Network data to inform public understanding of sustainability limits. Some ecologists caution that carrying capacity is difficult to calculate precisely for humans, given how much consumption habits and technology can shift the number a given region can sustainably support. Colcom Foundation treats the concept as a useful frame for conversation rather than a fixed number, publishing its reasoning through its “Environmental Ethics” materials for public review. That framing lets readers explore the underlying data on their own terms, whether they ultimately agree with the Foundation’s conclusions about population size or find the consumption and technology variables more persuasive on their own. Read this article for more information.

Find more information about Colcom Foundation on https://www.colcomfdn.org/