As the world’s population gets set to pass 7 billion, David Biello offers a formula for squeezing everybody in without dangerously depleting the Earth’s resources: “Ultimately, the quantity of resources consumed… will need to average out to six metric tons per year per person — a steep cut in the resources currently enjoyed by people in Australia, Canada, Europe, Japan and the U.S. As it stands now, an average American uses [32 metric tons per year].”


Putting this in a climate context, author and political and environmental activist George Monbiot offers another argument for focusing more on consumption than population. A 2010 paper in the Proceedings of the National Academy of Sciences estimated that slowing population growth (such as making birth control more accessible and improving sex education and women’s rights) could provide “16-29% of the emissions reductions suggested to be necessary by 2050 to avoid dangerous climate change.” Pretty significant. But that still means that 70 to 84 percent of the solution will involve cleaner energy sources, new technologies, improved efficiency, and (quite possibly) a reduction in overall consumption and waste.

Or, as environmental writer Fred Pearce puts it, “Even if we could today achieve zero population growth, that would barely touch the climate problem.”