Reduction in human population is not enough to have a meaningful positive impact on the environment. A new study, published October 27, 2014 in the Proceedings of the National Academy of Sciences of the USA, indicates that a new multi-scenario modelling of the global human population has found that even strict fertility restrictions or a catastrophic mass mortality would not provide a significant enough change in this century to solve issues of global sustainability.

Ecologists Professor Corey Bradshaw and Professor Barry Brook from the University of Adelaide’s Environment Institute note that the “virtually locked-in” population growth suggests the world must focus on policies and technologies that reverse increasing consumption of natural resources and enhance recycling for more immediate sustainability gains.

Efforts to reduce fertility through methods such as increased family-planning assistance and education, should still be undertaken, as this will lead to hundreds of millions less people to feed by mid-century.

Professor Bradshaw, Director of Ecological Modelling in the Environment Institute and School of Earth and Environmental Sciences, said in a statement, “Global population has risen so fast over the past century that roughly 14 percent of all the human beings that have ever existed are still alive today – that’s a sobering statistic.” He continued, “This is considered unsustainable for a range of reasons, not least being able to feed everyone as well as the impact on the climate and environment.”

Bradshaw noted, “Even a world-wide one-child policy like China’s, implemented over the coming century, or catastrophic mortality events like global conflict or a disease pandemic, would still likely result in 5-10 billion people by 2100.”

According to the United States Census Bureau, the most populous country in 2014 is China, with a population of 1,355,692,576, followed by India, with a population of 1,236,344,631.