Birds and Mammals Face New Threats from Global Population Growth

As global population continues to grow, hundreds of species of birds and mammals will be threatened with extinction in the next four decades, according to new research.

A recent United Nations report predicted world population will reach 9.6 billion by 2050 and the latest research from The Ohio State University supplements prior studies that indicate an increasing human population density will impact already endangered species. The latest data link expanding human population to new threats of extinction to other species.

Researchers determined that by the end of the next decade the average growing nation should expect 3.3 percent more threatened species, a figure that will jump to 10.8 percent by 2050.

Species loss - especially of key predators and prey - will, naturally, cause disruption in ecosystems.

The research was conducted as a continuation to a study that accurately predicted the number of newly threatened species by 2010. Researchers used the same equations to calculate the species threat between now and 2050.

Topping the list is the Democratic Republic of the Congo, which by 2050 is expected to see more than 20 newly threatened species due to expanding human populations. The United States ranked sixth, with calculations indicating the nation's growing population will threaten the lives of 11 species by 2050.

The model also suggested that in the 21 countries with a projected population decline, the number of threatened species will also decline by an average of 2.5 percent. Corroborating the latest study, results of the study ending in 2010 also found a lowered threat to species in countries with falling populations.

"We might be able to utilize that knowledge and use those countries to repopulate species that are native to those countries," said Jeffery McKee, the lead author of the study.

McKee also pointed out that his study only accounted for threats to mammals and birds due to expanding human population.

"Our projection is based on human population density alone. It doesn't take into account climate change, industrialization or wars. So the actual numbers that we predict for 2050 will be very different because everything we do will exacerbate the problem," he said in a statement. "You can do all the conservation in the world that you want, but it's going to be for naught if we don't keep the human population in check."

When global population stood at 6 billion, McKee led a project that calculated how much space each person on the planet could have to themselves if spread equally throughout the world. With 6 billion people on Earth, each person could have a space roughly equal to Ohio Stadium, which holds 102,000 football fans.

"If we get to 11 billion people, which is where we're supposed to peak, then the amount of space you have per person is a lot smaller than that stadium. When you're left with less space, there's virtually no space left for most other species," he said.

McKee said the growing human population and the footprint it leaves behind is "one of the biggest concerns of this century."

"Part of the resistance to addressing the problem is that human population size and growth is difficult to talk about and difficult to do anything about," he said. "To keep the human population in check, you have two options: increase the death rate or decrease the birth rate. I think the latter is the better choice."