According to Stanford population biologists Anne Ehrlich and her husband Paul Ehrlich, the world is facing a serious and unprecedented crisis. The whole of human civilization may be in danger of collapsing in the fairly near future, they say, primarily because of overpopulation and overconsumption by the wealthy.
But the Ehrlichs also believe they have a plan to prevent the crisis. And the critical first step is giving women equal rights, worldwide.
Their reasoning, laid out in a report published by the Proceedings of the Royal Society B, is based on research which finds that when women have greater rights, they have fewer children.
Giving women rights such as better access to education and nutrition, as well as ready access to birth control and emergency abortions, will lead to lower birth rates, creating less demand for resources in the long run, according to the Ehrlichs' report.
Women register to vote in Kenya on December 18, 2012 (Reuters)
The human population is expected to hit 9.6 billion by mid-century. The Ehrlichs say that granting women more rights worldwide could reduce that number to 8.6 billion, meaning a more manageable demand for resources.
At the moment, demand is severe. The report cites research stating that in order to continue to support the 7 billion people on Earth today at current standards of living, we would need roughly half an additional planet's worth of space and resources.
And if everyone on Earth consumed resources at the rate Americans do, we would need four to five new planets.
The Ehrlichs admit that convincing governments and societies around the world to grant women equal rights will be very difficult.
"After all," they write in their report, "there is not a single nation where women are truly treated as equal to men."
Women search for coins thrown by Hindu pilgrims on the last day of Makar Sankranti festival (Reuters)
But they suggest that even though it will be hard, changing the status of women and lowering international birth rates is an important part of preventing a major collapse.
It isn't the only sweeping change to the world's social structure the Ehrlichs are calling for, though. And they recognize that for the most part, societies aren't used to this kind of change.
The Ehrlichs say that throughout history, human societies have mobilized "to defeat an enemy at the gates," but never to confront "gradually worsening conditions that threaten real disaster for future generations."
"Perhaps the biggest challenge in avoiding collapse is convincing people, especially politicians and economists," they write, "to break this ancient mould and alter their behaviour relative to the basic population-consumption drivers of environmental deterioration."
Whether that will happen remains to be seen. But the Ehrlichs' ideas represent one more possible reason for societies around the world to improve the status of women.