Scientists have proposed a significant reduction in the global population, suggesting it needs to be halved to four billion by the year 2200 to alleviate the strain on the planet's resources and environment. The proposal, detailed in the journal Sustainable Development, frames this as a gradual decline rather than a catastrophic event.
The world's population has grown from under two billion to over 8.3 billion in the past century. Researchers argue that this rapid expansion has led to an unsustainable level of human impact on Earth's ecosystems. They cite trends over the last 50 years, during which the global population has doubled, CO2 emissions have more than doubled, energy use has tripled, and mineral extraction and pesticide use have quadrupled. Biodiversity has declined by more than half in the same period.
"Our collective impact upon the planet's ecosystems has become overwhelming and unsustainable," the scientists stated in their paper. Current projections indicate that the population could reach 11.4 billion by 2100, potentially doubling CO2 emissions and quadrupling plastic waste. Some research even suggests a peak of 12.4 billion by the late 2070s.
The researchers advocate for a strategy focused on empowering women in low-income countries with access to family planning services. They believe this approach, unlike coercive measures, would lead to a voluntary decline in fertility rates. The paper notes that when women have the agency to decide on family size, fertility rates often fall to or below the replacement level. Examples cited include Iran, where family planning services saw the number of children per woman drop from 4.08 in 1992 to 1.94 in 2001, and South Korea, which experienced a similar decline from 4.07 to 1.92 within 12 years of introducing family planning in 1972.
This approach aims to ease pressure on natural resources, reduce poverty in high-fertility regions, lessen pollution, and improve quality of life in densely populated areas. The researchers emphasize that this is a "pro-nature and pro-human strategy."
However, the proposal acknowledges potential controversies. Economic growth is often linked to a robust working-age population, and declining birth rates can lead to an aging population and a shrinking labor force. South Korea, for instance, now has over 20% of its population aged 65 or older, and the International Monetary Fund projects a potential shrinkage of the labor force by over a quarter by 2050, impacting economic growth. Despite these concerns, the researchers suggest that addressing ecological sustainability may require reassessing the necessity of continuous economic growth, stating, "Ever-growing wealth and consumption are not ecologically sustainable, and the sooner our societies grapple with this inconvenient truth, the better."