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.”

“If there was a perfect slum, Kibera would be it.” The notoriously overcrowded and underserved settlement in the Kenyan capital of Nairobi captivates the public imagination, engendering visions of urban violence, poverty, and hopelessness, said Caroline Wanjiku Kihato of the University of the Witwatersrand at the Wilson Center on February 18. The area was ravaged by ethnic violence that erupted across the country following Kenya’s disputed 2007 elections, pitting neighbor against neighbor in tribal clashes that killed more than 1,000 people, displaced many thousands more, and provoked an alarming surge in sexual violence.

The Wilson Center’s Urban Sustainability Laboratory, in partnership with USAID, International Housing Coalition, World Bank, and Cities Alliance, is pleased to announce the 5th Annual Urban Poverty Paper Competition for graduate students. The competition calls on students currently enrolled in a Master’s or PhD program to submit paper abstracts on topics relating to urban poverty in the developing world.

As policymakers respond to the threat of climate and environmental change, the concept of resilience has found itself at the center of discussion. Few scientists and policymakers, however, can come to a consensus on how to define, evaluate, and build resilience.

This past December, Bangladesh turned 42, bringing the country Henry Kissinger once predicted would become a “basket case” into comfortable middle age (though perhaps this analogy breaks down for countries like Switzerland, age 722).

“What’s become clear to me on population is that it’s really a local issue,” said Andrew Revkin in an interview at the Wilson Center. “You get the impression, ‘Oh didn’t we solve that problem?’” And to some extent, demographic shifts around the world are largely heading in the direction people anticipated, with a leveling off mid-century. But “no one really knows what happens then,” he said. “All it takes is a tiny diversion of fertility rates and things could really grow or shrink.”

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.