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.”

The original version of this article, by Chris Berdnik, appeared on the Pulitzer Center on Crisis Reporting.

I meet Keo Mao, 42, in the floating fishing village of Akol on Cambodia’s Lake Tonle Sap. The houses here move seasonally with the lake, which expands by a factor of five during the monsoon rains and recedes again in the dry months. Fish supply about 80 percent of the animal protein eaten by Cambodians, and about 60 percent of the inland catch comes from the Tonle Sap.

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]

The original version of this article, by Kaja Jurczynska, appeared on Population Action International’s All Access blog.

Pakistan is at a crossroads, and not for the reasons you might think.

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.

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 do melting Himalayan glaciers have to do with food security in Cambodia? Not much, thought an aid practitioner trying to boost food security along the lower reaches of the Mekong River – until she heard a colleague working on the Tibetan Plateau describe the downstream implications of climate change in the Himalayas. Everything she was working on, she suddenly realized, could be literally washed away.