The Wilson Center Policy Briefs are a series of short analyses of critical global issues facing the next administration that will run until inauguration day.

Seven billion people now live on Earth, only a dozen years after the global population hit six billion. But this milestone is not about sheer numbers. Demographic trends will significantly affect the planet’s resources and people’s security.

High mountain regions face grave environmental challenges with climate change impacts already as severe as any place on earth. Temperature increases are expected to be greater at higher altitudes than at sea level, and glaciers and snowfields are retreating in many areas, increasing the risk of catastrophic glacial lake outburst floods, affecting fresh water supplies for hundreds of millions of people, and exacerbating territorial and natural resource disputes.

Despite progress over the years, Ethiopia’s Guraghe zone, located in the Southern Nations, Nationalities, and People’s Region, faces many development challenges. As senior monitoring and evaluation officer in the Guraghe People’s Self-help Development Organization (GPSDO), I have been working in this region for more than five years trying to reduce poverty and improve socio-economic development. The organization as a whole has been here for more than 50.

It is well known that public health issues that affect the world’s most vulnerable populations – food insecurity, maternal and child health, water- and sanitation-related disease, and resource scarcity – are inextricably linked. Where these linkages are strongest, experience on the ground has shown that community-based integrated approaches to development provide more effective and sustainable solutions over vertical, sector-based programs. But so far, there are very few comprehensive evaluations providing strong quantitative evidence of this advantage.

1.8 million food producers using improved technologies or management practices. Nearly 9 million children reached through nutrition programs. 2.4 million hectares under improved technologies or management practices. New mechanisms for donor coordination. A forward-looking agricultural research agenda. Innovative private-sector partnerships to support smallholder farmers. These are among the successes reported for the first three years of Feed the Future, the U.S. government’s new global hunger and food security initiative.

The future is urban – but is it sustainable?

For decades – centuries, really – warnings have been issued: The burgeoning human population will outgrow the planet’s capacity to sustain us. The formula seems simple. More people equals fewer resources and greater environmental damage.

The CIA may have shut down its dedicated climate change center earlier this year, but a recently released report sponsored by the intelligence community reaffirms the deep connection between climate change and national security. New threats to U.S. national security – like increased food and water insecurity and more natural disasters requiring humanitarian assistance – have emerged as climate change creates unprecedented changes in the global environment.

Population growth “is highly concentrated in what are today the poorest and least well-governed areas of the world,” said George Mason University professor Jack Goldstone at the Wilson Center on December 5.

Goldstone was joined by Suzanne Ehlers, president and CEO of Population Action International (PAI), and Matthew Erdman, population-health-environment technical advisor at USAID, to discuss the implications of seven billion people and counting for the environment as part of the joint Wilson Center-George Mason University Managing the Planet series. [Video Below]