FLINDERS UNIVERSITY — A study published in Environmental Research Letters in May 2026 concluded that humanity has surpassed Earth's sustainable carrying capacity. The research, led by Corey Bradshaw, identified a 'negative demographic phase' beginning in the 1960s, during which adding more people no longer translates into faster societal or economic growth.

The study analyzed more than 200 years of global population and environmental data. It found that while global population growth accelerated before the 1950s—spurring innovation and technological advances—the growth rate began slowing in the early 1960s even as total population continued to rise. By May 2026, the global population had reached 8.3 billion.

Bradshaw, Matthew Flinders Professor of Global Ecology, stated, "Earth cannot keep up with the way in which we are using resources. It cannot support even today's demand without major changes, with our findings showing that we are pushing the planet harder than it can possibly cope." He described the post-1960s shift as 'a negative demographic phase,' emphasizing that population size has become a stronger driver of environmental change than per capita consumption alone.

The research linked total population size to rising global temperatures, expanding ecological footprints, and increased carbon emissions during this phase. Dependence on fossil fuels has temporarily masked the effects of ecological overshoot by supporting food production and industrial growth, but this reliance has intensified climate change, pollution, and environmental degradation.

Bradshaw stated, "The truly sustainable population is much lower and closer to what the world supported in the mid-twentieth century. Our calculations show a sustainable global population closer to about 2.5 billion people if everyone were to live within ecological limits and comfortable, economically secure living standards."

Global population is projected to peak between 11.7 and 12.4 billion by the late 2060s or 2070s if current trends continue.