Following the steady economic growth that many African countries have experienced in recent years and continued population growth, urbanization has accelerated rapidly on the continent as people turn to cities to take advantage of new economic opportunities. But growing cities have led to another problem. According to a new Food and Agriculture Organization (FAO) report, Growing Greener Cities in Africa, urban populations are exceeding the capacity of African cities to provide food for them, putting nearly 300 million people at risk of hunger and malnutrition, and greener strategies – urban agriculture and better water use – could help considerably.

Historically, the concept of “water wars” – inter-state wars fought solely over water – has been fairly unsubstantiated. But continued population growth, accelerating development, and environmental changes are making water more scarce and in turn increasing the chances of related tensions and violence. To illustrate the growing role water plays in tensions around the world, Al Jazeera has put together a map linked to a series of stories they’ve done on water “flashpoints.”

In 1979, Egyptian President Anwar Sadat famously said that “the only matter that could take Egypt to war again is water.” Sadat’s message was clear: the Nile is a matter of national security for Egypt.

Indeed, Egypt relies on the Nile for 95 percent of its water. But it is not the only state with an interest in the world’s longest river. There are 11 states in the Nile River basin, which stretches from Africa’s Great Lakes region – Tanzania, Uganda, Kenya, Rwanda, Burundi, and the Democratic Republic of the Congo – to the Ethiopian and Eritrean highlands through South Sudan, Sudan, and Egypt to the Mediterranean Sea.

Over the next two decades, as many as three billion people will join the middle class, even as billions more live without electricity, modern cooking fuel, and safe and reliable access to food and water. Resources are becoming more scarce and more difficult to extract, and combined with environmental factors ranging from climate change to soil erosion, those changes will make meeting middle class demand all the more difficult while leaving the world’s poorest more vulnerable to price shocks and resource shortages. In a recent report, the McKinsey Global Institute concludes that nothing less than a “step change” in how resources are managed will be required if individuals, businesses, and governments are to overcome these trends and pave the way for a more sustainable and equitable future.

The original version of this article, by Christina Larson, appeared on Yale Environment 360.

Bouncing along bad roads in a jeep through central Mongolia, with bright blue skies and high clouds overhead, we drive for miles through a treeless landscape, passing only dry grasslands dotted with cattle and white yurts. But as we head north – myself, two U.S. scientists, and one Mongolian forestry expert – we begin to notice Siberian pine and larch growing on the northern slopes of rolling hills, but not the southern slopes, and at some elevations, but not others. In water-scarce Mongolia, as my travel companion Neil Pederson of Columbia University’s Lamont-Doherty Earth Observatory explained, the precarious growth of trees is limited by temperature and moisture availability; small variations – northern slopes are slightly cooler and wetter – can make all the difference.

In the “first spatially explicit comparison of groundwater use, availability, and environmental flow for aquifers globally,” a new article in Nature finds that the “size of the global groundwater footprint is currently about 3.5 times the actual area of aquifers.” An aquifer’s footprint is the theoretical size it would need to be to sustainably support use at its current rate, so groundwater footprints being much larger than their corresponding aquifers is a sign of overuse.

Climate change “has been thought of in many quarters as something that affects folks ‘over there,’ and not as much domestically, and I think that’s a mistake,” said ECSP’s Geoff Dabelko in a recent podcast with the Zurich-based International Relations and Security Network. “I think folks are coming to a realization that there are very high economic, political, and ultimately security stakes for the United States.”

The original version of this article, by Michael Kugelman, appeared on Dawn.

There’s been much discussion lately about the “water kit,” a mysterious contraption that a purported Pakistani engineer insists will enable cars to use water as fuel.

Yet missing from this debate is a basic but critical fact: Pakistan is dangerously water-deficient. Per capita availability hovers just above the scarcity threshold of 1,000 cubic meters. In several decades, availability could plummet to 550 cubic meters.