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]

Without decisive action, global temperatures could rise by at least four degrees Celsius (seven degrees Fahrenheit) by the end of the century. A new World Bank report says that such a world would be “so different from the current one” that it would be difficult to even anticipate the challenges we would face.

“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?”

Five million people die each year due to climate- or carbon-related causes, and total mortality by 2030 could total 100 million people, according to new report from DARA, a nonprofit organization that works to improve aid to those affected by conflict and climate change and quantify the global cost of climate change and carbon use. But the report has drawn some fire for being too alarmist.

Sub-Saharan Africa is a key region both for conservationists and those working for improved public health. Nine of the world’s 34 biodiversity hotspots are in sub-Saharan Africa, as are two of the five most important wilderness areas. This hotbed of biodiversity is also home to many of the world’s most rapidly growing populations and swelling urbanization, which is putting increased pressure on natural resources.

Tanzania’s Saadani National Park is a hotbed of biodiversity and, like other national parks in the region, it’s surrounded by human activity. A report by the BALANCED Project, “Population, Health, Environment Situational Analysis for the Saadani National Park Area, Tanzania,” provides a snapshot of the population, health, and environment situation inside the park to serve as a baseline for future activities of the Tanzania Coastal Management Partnership (TCMP) – a joint initiative of the government of Tanzania, USAID, and the University of Rhode Island’s Coastal Resources Center. A behavioral monitoring system implemented in June 2009 used surveys that reached a total of 437 respondents (54 percent women) from eight villages to analyze the “behaviors that positively and negatively influence the utilization and condition of natural resources.”  The surveys found that arable land is scarce, fisheries are being depleted, and people have inadequate access to healthcare, water, sanitation, fuel, and family planning resources. The results suggest a strong case for expanding TCMP’s existing integrated approach – combining HIV/AIDS, conservation, and livelihoods goals – to include promotion of positive behavior changes, particularly as they relate to family planning and the effects of population growth on biodiversity loss and resource depletion.

In 2011, a record 34 billion cubic tons of carbon dioxide were emitted from man-made sources. Half the emitted CO₂ stays in the atmosphere, about a quarter is absorbed on land (as trees grow, for example), and the remainder is absorbed by the ocean. Unsurprisingly, this incredible amount of carbon dioxide significantly changes the ocean environment. Over time, increased absorption of carbon dioxide in the oceans has led to ocean acidification, and overall warming has also led to warming of ocean waters – both changes impact marine ecosystems and the people who rely on them.