What are the environmental implications of changing household sizes? A recent article by Mason Bradbury, M. Nils Peterson, and Jianguo Liu, published in Population and Environment, analyzes data from 213 countries over 400 years and finds the average number of occupants per home tends to decline as population grows. This dynamic, they write, indicates that accommodating housing could prove to be one of “the greatest environmental challenges of the twenty-first century.” As countries develop and urbanize, “according to convergence theory, household size decreases (often from greater than five to less than three).” Other cultural shifts, like increasing divorce rates, urban sprawl driven by rising affluence, decreasing numbers of multigenerational households, and larger houses (in the United States, homes more than doubled in size between 1950 and 2002, according to the article) compound the issue. As population growth continues in parts of the world, these trends pose critical questions for conservation and environmental sustainability, since “households are the end consumers of most natural resources and ecosystem services.”

In Lake Victoria and Lake Chilwa basins, interconnected development challenges defy sectoral boundaries, said experts at the Wilson Center on February 10. According to Deepa Pullanikkatil of Leadership for Environment and Development and Doreen Othero of the Lake Victoria Basin Commission, growing populations, shrinking resource bases, and persistent human health concerns demonstrate the need for integrated development approaches that combine population, health, and environmental (PHE) interventions. “We need different sectors working together to achieve the greater goal,” said Pullanikkatil. [Video Below]

Against the stunning backdrop of Marojejy National Park, I recently crossed paths with a conservationist from a very different background, working on the opposite side of Madagascar. But, it turns out, the communities we work with face many of the same challenges, and our meeting spawned a new population, health, and environment (PHE) program.

The original version of this article, by A. Tianna Scozzaro, appeared on Population Action International’s All Access blog.

For the past 11 months, a group of United Nations member states has been holding meetings seeking input on future goals for sustainable development once the Millennium Development Goals (MDGs) expire in 2015. Led by co-chair ambassadors from Hungary and Kenya, this Open Working Group of 69 countries has delved into topics ranging from governance to health and everything in between.

2014 promises to be a superlative year – and that’s not necessarily a good thing. Complex, “super” disasters like Super Typhoon Haiyan are becoming more frequent, more systemic, and more destructive. Global trends, from population dynamics to food, water, and energy scarcities, threaten to further complicate the playing field. But by finally getting serious about resilience – the much discussed buzzword of 2013 – we might reduce our vulnerability, restore our communities, and build back better, rather than just picking up the pieces.

Twenty thousand girls under the age of 18 give birth every day, and 90 percent of these births occur within the context of marriage, according to the UN Population Fund’s latest State of the World Population report. This year’s edition, launched at the Wilson Center on October 30, focuses on adolescent pregnancy and finding ways to better protect this vulnerable group of young women.