Can the ocean and river ecosystems of the world survive the sand dredging needed to supply the cement for global construction? In September’s most popular post, Kimberly Yang explores the impact that widespread sand mining is having on China’s rivers and coastal waters, driven by China’s construction boom. The consequences are significant, but Chinese construction and real-estate companies are exploring ways to lessen the environmental impact of sand dredging.

The diplomatic and political challenges of water are the focus of two of the month’s most read posts. Retreating Andean glaciers and related water scarcity is creating diplomatic stress between Bolivia, Chile, and Peru, writes Kate Cullen, and Brett Walton of Circle of Blue offers a retrospective on how Cape Town managed its water crisis, how it can prevent such a crisis from recurring, and what lessons can be learned by cities around the world.

The boom in green energy infrastructure is driving demand for cobalt, lithium, and other minerals, creating new potential for conflict in fragile states with large deposits of these minerals, and Clare Church argues that new mechanisms are needed to ensure responsible sourcing.

Elizabeth Wang highlights research by the Peace Research Institute Oslo into one of the overlooked consequences of conflict—higher rates of maternal and child mortality—and the need for more research to understand the potential solutions to elevated civilian mortality in conflict settings.

1. The Crushing Environmental Impact of China’s Cement Industry by Kimberly Yang

2. As Andean Glaciers Retreat, So Does Regional Security by Kate Cullen

3. Green Conflict Minerals: Investigating Renewable Energy Supply Chains in Fragile States by Clare Church

4. Cape Town’s Harrowing Journey to the Brink of Water Catastrophe by Brett Walton

5. Mothers on the Front Lines: Armed Conflict, Aid Distribution, and Maternal and Child Health by Elizabeth Wang