North American skies have grown measurably quieter since 1970. Between that year and 2020, the continent’s bird populations shrank from approximately 10 billion to 7.1 billion, a loss of 2.9 billion birds across five decades. Wild vertebrate populations worldwide fell 69% over the same span, according to the WWF Living Planet Report 2022. Colcom Foundation, a Pittsburgh-based nonprofit established in 1996, has built its conservation work around a question that ecological record keeps raising: why haven’t per capita efficiency gains been enough?
Per capita CO2 emissions in the United States fell 35% between 1970 and 2021, from 21.33 to 14.04 metric tons per person. Total national emissions rose 15% anyway. U.S. population grew 62% across that period, climbing from 205 million to 332 million people, and the arithmetic overtook the progress. Cleaner per person; more in aggregate.
The Equation Behind Colcom Foundation’s Conservation Approach
Cordelia Scaife May founded Colcom Foundation in 1996, at age 68, after tracking environmental science for decades. May, a Pittsburgh philanthropist, had recognized the gap between per capita improvement and total ecological burden as early as the 1950s. “Human activity is putting such a strain on the natural functions of Earth that the ability of the planet’s ecosystems to sustain future generations can no longer be taken for granted,” she said. The foundation was substantially funded following her death in 2005 and continues today with a formal mission to foster a sustainable environment to ensure quality of life for all Americans.
Colcom Foundation’s conservation analysis centers on the equation I = P × A × T, developed by environmental scientists Paul Ehrlich and John Holdren. Environmental impact (I) equals population size (P) multiplied by per capita consumption (A) multiplied by technological efficiency (T). Changing any single variable while leaving the others unaddressed shifts the total ecological burden without reducing it. The foundation traces this environmental philosophy directly to Earth Day 1970, which first placed per capita overconsumption and population growth side by side as ecological drivers on a national and global scale. Conservation science addressed the first variable extensively in the decades that followed. Population growth as a driver received substantially less sustained attention.
Biocapacity utilization, as measured by the Global Footprint Network, anchors the foundation’s primary sustainability analysis. Biocapacity tracks how a population’s resource consumption compares to the productive capacity of available land and water. In 1970, the United States consumed approximately 227% of its available biocapacity. Fifty years of efficiency gains later, that figure stood at approximately 240%, even as per capita biocapacity use fell more than 20% over the same period. A population consuming less per person but larger in total number still consumed more in aggregate.
Where Conservation Science and Habitat Data Converge
Habitat conversion follows the same trajectory. Approximately 133,000 square miles of U.S. land had been converted to human-made surfaces by 1990; by 2020, that total exceeded 187,000 square miles. Research by Kolankiewicz et al. (2022) found that areas with rapid population growth showed consistently higher rates of habitat loss. Radeloff et al. (2010) documented that residential growth near the boundaries of protected areas outranks distant industrial activity as the primary conservation threat to those reserves. Suburban expansion at the edges of wilderness accumulates quietly and at scale.
A 2004 study by McKee et al. across 114 nations found that human population density and species richness account for 88% of variability in threatened bird and mammal species. A 2022 study by Cafaro et al. in Biological Conservation confirmed population growth as a fundamental driver of biodiversity loss, and specifically found that population decrease facilitates ecological restoration. Both studies appear in the foundation’s research library, alongside data from the WWF Living Planet Report 2022 documenting global vertebrate decline.
Two frameworks now central to conservation policy illustrate the scale of the challenge. The 30×30 initiative targets protection of 30% of U.S. land and water by 2030. E.O. Wilson’s Half-Earth proposal advocates preserving 50% of Earth’s surface to protect roughly 80% of species. Colcom Foundation applies biocapacity analysis directly to both targets: under 30×30 assumptions, effective U.S. biocapacity utilization reaches approximately 341%; under Half-Earth, roughly 478%. Ambitious conservation goals pursued against a backdrop of continued growth face a compounding arithmetic problem that protection targets alone cannot resolve.
From Framework to Fieldwork: Colcom Foundation’s Regional Grantmaking
Colcom Foundation operates on two tracks simultaneously. Nationally, it funds public education, research, and nonprofit organizations that examine population-environment relationships. Regionally, it directs conservation investment into southwestern Pennsylvania, where Cordelia Scaife May built her philanthropic legacy and where the foundation’s grantmaking has now accumulated across two decades.
Most recently, the foundation awarded $1 million to the Western Pennsylvania Conservancy (WPC) to support targeted land acquisitions in the Upper Allegheny Watershed Region. That 7,600-square-mile area encompasses forests, wetlands, and farmland that includes French Creek, recognized as one of the most biologically diverse streams of its size in the northeastern United States. Over three years, WPC aims to permanently protect 1,000 acres of high-priority land. WPC has protected nearly 94,000 acres in the Upper Allegheny over the organization’s history.
Colcom Foundation’s current support for Upper Allegheny watershed work follows a $2 million grant in 2006 that launched WPC’s “Waters for Life” initiative and produced the Conservation Blueprint, a science-driven framework prioritizing high-biodiversity areas using 25 years of accumulated data. That original investment leveraged more than $4.2 million in additional funding across basin-wide work covering the Allegheny, Juniata, and Clarion River systems. Stabilized streambanks, removed dams for fish passage, restored riparian buffers: the compounding returns from early conservation investment are still accumulating.
Earth Day 1970 named two problems. One received 55 years of sustained policy attention. The foundation’s updated origins and mission resource documents the ecological record of those decades alongside a conservation framework built to address both. For the 2.9 billion birds no longer counted in North American skies, the gap between per capita progress and aggregate outcomes is documented in the record itself.