Have we vastly underestimated the total number of people on Earth?

Article forund here:
https://www.newscientist.com/article/2472604-have-we-vastly-underestimated-the-total-number-of-people-on-earth/

From New Scientist By Chris Stokel-Walker

A new way of estimating rural populations has found that we may be undercounting people who live in these areas, potentially inflating the global population beyond the official count of 8.2 billion – but not everyone agrees

18 March 2025

Our estimates of rural populations have systematically underestimated the actual number of people living in these regions by at least half, researchers have claimed – with potentially huge impacts on global population levels and planning for public services. However, the findings are disputed by demographers, who say any such underestimates are unlikely to alter national or global head counts.

Josias Láng-Ritter and his colleagues at Aalto University, Finland, were working to understand the extent to which dam construction projects caused people to be resettled, but while estimating populations, they kept getting vastly different numbers to official statistics.

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To investigate, they used data on 307 dam projects in 35 countries, including China, Brazil, Australia and Poland, all completed between 1980 and 2010, taking the number of people reported as resettled in each case as the population in that area prior to displacement. They then cross-checked these numbers against five major population datasets that break down areas into a grid of squares and estimate the number of people living in each square to arrive at totals.

Láng-Ritter and his colleagues found what they say are clear discrepancies. According to their analysis, the most accurate estimates undercounted the real number of people by 53 per cent on average, while the worst was 84 per cent out. “We were very surprised to see how large this underrepresentation is,” he says.

While the official UN estimate for the global population is around 8.2 billion, Láng-Ritter says their analysis shows it is probably much higher, though declined to give a specific figure. “We can say that nowadays, population estimates are likely conservative accounting, and we have reason to believe there are significantly more than these 8 billion people,” he says.