October 28, 2014
Catastrophic Population Reduction Won’t Save The Planet, New Study Claims
Chuck Bednar for redOrbit.com - Your Universe Online
Global population levels have reached the point where not even strict fertility restriction or a catastrophic mass mortality event would bring about enough of a change to solve global sustainability issues, according to new research from ecologists at the University of Adelaide's Environment Institute.In research published Monday in the Proceedings of the National Academy of Sciences, professors Corey Bradshaw and Barry Brook conducted multi-scenario human population models and determined that population growth was essentially “locked-in.” For more immediate sustainability gains, they write that the focus should be on new policies and technologies that reduce the increasing consumption of natural resources and enhance recycling.
“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,” Professor Bradshaw, Director of Ecological Modelling in the Environment Institute and School of Earth and Environmental Sciences, said in a statement. “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.”
“We examined various scenarios for global human population change to the year 2100 by adjusting fertility and mortality rates to determine the plausible range of population sizes at the end of this century,” he added. “Even a worldwide 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 Steve Conner of The Independent, there are approximately 7.1 billion people currently living on Earth, and researchers believe that this number could increase to about nine billion by 2050 and 25 billion by 2100. However, Conner noted that those estimates are based on current fertility rates, which are expected to decrease in the decades ahead.
Professor Bradshaw told Conner that the purpose of the study was to examine population numbers through the eyes of an ecologist evaluating the natural impact on animals in order to determine whether factors such as global pandemics or world wars could have a significant impact on population projections. What they found, the professor said, was that the size of the human population was so large that it “has its own momentum. It’s like a speeding car traveling at 150mph. You can slam on the brakes but it still takes time to stop.”
With such a large percentage of the historic global population currently living and using the planet’s resources, the impact on the environment is larger than ever before, according to BBC News environmental correspondent Matt McGrath. Consumption rates are increasing, and it is expected that deforestation for agricultural purposes, urbanization, the pressure on species, pollution and climate change are expected to increase in the years ahead, even as per-capita fertility decreases.
The University of Adelaide researchers constructed nine different scenarios from population change through 2100 using World Health Organization (WHO) and US Census Bureau data, McGrath said. They also devised catastrophic scenarios to examine the impact of climate disruption, wars, pandemics and even population control limits, and found that there was no “short-term fix” to curb the population and its impact on the planet, he added.
“We were surprised that a five-year WWIII scenario mimicking the same proportion of people killed in the First and Second World Wars combined, barely registered a blip on the human population trajectory this century," said Brook, who was Chair of Climate Change at the Environment Institute during the study and is currently Professor of Environmental Sustainability at the University of Tasmania.
“Often when I give public lectures about policies to address global change, someone will claim that we are ignoring the 'elephant in the room' of human population size,” he continued. “Yet, as our models show clearly, while there needs to be more policy discussion on this issue, the current inexorable momentum of the global human population precludes any demographic 'quick fixes' to our sustainability problems.”
“Our work reveals that effective family planning and reproduction education worldwide have great potential to constrain the size of the human population and alleviate pressure on resource availability over the longer term. Our great-great-great-great grandchildren might ultimately benefit from such planning, but people alive today will not,” the professor concluded.