Researchers propose a smaller population for a healthier planet.

For centuries, humanity's growth has been seen as a sign of progress — but a controversial new study is challenging that idea with a startling proposal. Researchers argue that reducing the global population to around 4 billion people could help ease pressure on Earth's resources and create a more sustainable future. The claim has sparked debate over whether a smaller population could truly benefit both the planet and future generations, raising a major question: how many people can Earth realistically support?