There are 8.3 billion people living on planet Earth. I know because I read it in a report by the U.S. Census Bureau, and why would our government lie to us?
Don't answer that. The 8.3 billion is "official," in that it's generally accepted worldwide. It's calibrated by careful scientific measurement, certified by experts, and given the Good Housekeeping Seal of Approval.
One scientist in Finland says that number is baloney.
Josias Láng-Ritter, a postdoctoral researcher at Aalto University in Finland and lead author of the study published in the journal Nature Communications, says that these numbers are seriously underrepresenting rural areas.
Lang-Ritter and his team examined 300 rural dam projects. The scientist chose them because governments and companies have to reimburse residents displaced by the dam's construction. Those numbers are readily available and can be checked against rural population estimates by WorldPop, GWP, GRUMP, LandScan, and GHS-POP
“When dams are built, large areas are flooded and people need to be relocated,” Láng-Ritter said in a press statement. “The relocated population is usually counted precisely because dam companies pay compensation to those affected. Unlike global population datasets, such local impact statements provide comprehensive, on-the-ground population counts that are not skewed by administrative boundaries. We then combined these with spatial information from satellite imagery.”
It's hard to argue with Láng-Ritter. But can he extrapolate the undercounts in rural areas to encompass the entire planet?
‘While our study shows accuracy has somewhat improved over decades, the trend is clear: global population datasets miss a significant portion of the rural population. With the same basic practices in place, it’s unlikely that slightly improved input data could correct for this level of bias. And even if the most recent population maps reflected reality, earlier datasets have influenced decision-making for decades and are still used to monitor change, for instance, providing a distorted picture of movement over time from the countryside to urban areas,’ says Láng-Ritter.
Not every scientist agrees.
However, not everyone is convinced by this research. Stuart Gietel-Basten from the Hong Kong University of Science and Technology told New Scientist that while increased investment in rural population data collection would be beneficial, the idea that Earth could contain a few billion more human inhabitants that we thought is extremely unlikely. “If we really are undercounting by that massive amount, it’s a massive news story and goes against all the years of thousands of other datasets.”
When trying to count such a massive population, a few hundred or maybe even a few thousand may slip through the cracks. But a few million or even billion would upend our understanding of human occupation on this planet. Scientists will need a bit more evidence before rethinking decades of dataset research.
"We were surprised to find that the actual population living in rural areas is much higher than the global population data indicates — depending on the dataset, rural populations have been underestimated by between 53% to 84% over the period studied. The results are remarkable, as these datasets have been used in thousands of studies and extensively to support decision-making, yet their accuracy has not been systematically evaluated," says Láng-Ritter.
Could the world population really be more than 12 billion? 16 billion? Since most of the undercount is in rural areas, there's plenty of room for more people in many of them.
Lang-Ritter points out that this population bias toward rural residents has serious consequences. These population estimates don't exist in a vacuum. They are used to divide resources based on population estimates. Adding 4-8 billion people complicates the job of governments, who have to account for the additional people in their countries.
So it may sound like an esoteric argument, but we can't ignore the real-world consequences.
