Population growth has a significant impact on the natural environment, but that impact is shaped by a wide range of mediating factors — including technology, consumption patterns, economic policies and political choices. Slower population growth alone will not solve today’s environmental challenges. But slower growth—together with reduced resource consumption in affluent countries–could help give us a fighting chance to meet those challenges, by reducing pressure on natural systems that are reeling from stress.
Some people have much greater environmental impact than others. We in the U.S. comprise only 5% of the world’s population, but account for 25% of all energy use.
Still, while there are great disparities in environmental impact among the world’s citizens, everyone has some impact. And the citizens of the developing world must increase their resource use—and environmental impact—so that the half of humanity that lives on $2 a day can escape from poverty.
Eight billion would be better than 10.5 billion—for people and the planet. If we take seriously the twin imperatives of sustainability and equity, it becomes clear that it would be easier to provide a good life – at less environmental cost – for eight billion rather than 10.5 billion people. And slower growth could help give families and nations a chance to make essential investments in education, health care and sustainable economic development.
Slowing population growth is not all we must do. Rapacious consumption in the affluent countries drives environmental destruction worldwide; changing our own systems of production and consumption must be the top priority if we are to preserve a habitable planet.