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.

We live in a world that is different from that inhabited by our ancestors in many profound ways. Among the most important changes is that, for the first time, almost half of the world’s people live in cities. According to the United Nations, in 2008 the global urban population surpassed half of the world’s population of 6.7 billion compared with 13 percent a century ago and 3 percent a century before that. This trend will require profound changes in the way the U.S. government addresses everything from development policy to international security.

Carbon offsets have fallen in and out of favor since they were established with the Kyoto Protocol in 1997. Critics say they allow wealthy organizations to placate consumers and claim their products are “green” without making any real, lasting changes. But, if the scheme works properly, some action is supposed to be taken somewhere, so what is it like at one of these credit-producing organizations?

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]

“There is as much of that water on the planet today as when the first amphibian flopped ashore; as much as when the ancient Greeks divined the future in the babble of brooks,” writes William Wheeler in The Christian Science Monitor. “So why do experts in science, economics, and development warn that a ‘global water crisis’ threatens the stability of nations and the health of billions?”

Over the past few years, large-scale acquisition of land by foreign or domestic firms, be they public or private, have been making headlines. But although these “land grabs” have received a great deal of attention, their details remain largely unknown. Which countries are the primary investors? Which are the main targets? What is the land used for?

Adapting to the effects of climate change is increasingly becoming an important component of many international development efforts. But how that integration occurs and what it looks like is an open question. To help answer that, the Climate Change and African Political Stability Program (CCAPS) at the University of Texas at Austin recently released a new database that for the first time tracks all the climate-related aid in one country – Malawi.

The original version of this article, by Vik Mohan, appeared on Blue Ventures’ blog.

I recently spent a hectic and intense couple of weeks in the village of Andavadoaka, where Blue Ventures’ community health project is based, during my annual visit to Madagascar. Although I founded our Safidy (meaning “choice”) health program several years ago, each return visit brings new and inspiring stories and lessons from our team on the ground.

The fault line between nomadic pastoralists and sedentary agriculturalists in sub-Saharan Africa has emerged as one of the most dominant stories of climate-related conflict. But according to Edna Wangui, a professor at Ohio University who studies communities in Kenya and Tanzania, pastoralism is different from many people’s perceptions.