The Lanjiang river in Eastern Zhejiang, China, reached its peak water level of 100 feet the night of June 25, 2017. Lanxi residents remember this day as “6.25,” marking the worst flood since 1955. Elsewhere in China that month, 7.3 million people were affected by floods, landslides, and heavy rains in northwestern Sichuan Province alone. Northern Guangxi suffered direct economic losses of 2.9 billion RMB (US$460 million). In the autonomous regions, 92,000 people were relocated. Flash floods caused the deaths of 10 people and forced 76,800 people to evacuate from Shanxi Province.

Natural bioshields—wetlands, forests, and urban green spaces—are critical tools for reducing the impacts of disasters on vulnerable communities. Between 1994 and 2014, nearly 7,000 natural disasters occurred worldwide, causing an average of almost 68,000 deaths each year. Climate change, growing populations, and widening economic inequality are all expected to increase the impacts of disasters. Bioshields—nature’s own solutions to natural hazards—can help protect people from these dangerous floods, storms, and heat waves.

In 2014, we met with some of the technical leads of a major Chinese river basin authority in Beijing and asked them whether they were more worried about pollution or climate change impacts. Both, the engineers replied. Pollution affects us every day, they said, but changes in the climate erode our ability to supply drinking and irrigation water, manage floods, and generate electricity.

China must address its environmental and climate change challenges, such as reducing water pollution and building resilience to droughts, floods, and long-term climate shifts. But existing sources of finance have not met the growing demand for environmental projects.

After pirates hijacked an Iranian fishing vessel last year near Bosasso, a major seaport in Puntland, Somalia, local authorities observed that the offending boat was casting nets without a license. While piracy has diminished since 2008-2012, when these waters became some of the most lawless in the world, a spate of incidents in 2017-8 has made it clear that the conditions that led to piracy—including incursions from foreign fishing boats—are still a major problem.

The Mississippi River Valley has been hit by droughts, floods, extreme heat, and tornadoes that resulted in damages totaling over $50 billion since 2011. From 2005 to 2017, that total eclipses $200 billion with each effected state incurring a minimum $5 billion in damages. One positive result in reaction to those natural disasters was the formation of the Mississippi River Cities & Towns Initiative (MRCTI), a coalition of mayors focused on resilience and adaptation programs. Last week, mayors of the ten states along the river met with leaders from the global and North American insurance industry to discuss reducing vulnerabilities and building resilience in the face of climate-related disasters.

“Most risk in African cities is not catastrophic. It’s not even episodic, but it is every day,” said Mark Pelling, a professor at King’s College, London, at a recent event on urban risk and resilience in sub-Saharan Africa. With rates of rural-to-urban migration reaching record highs, more than half of the urban residents in sub-Saharan Africa live in informal settlements, where they lack basic infrastructure and access to critical resources. Integrated projects like Pelling’s Urban ARK seek to build more resilient communities in cities and informal settlements. “African cities are dynamic and are growing,” said Pelling—but so is the vulnerability of their residents to environmental change, natural disasters, and conflict.

“Some people are more vulnerable than others” to climate change, said Judy Oglethorpe, senior director of Multilateral Program Development of the World Wildlife Fund-US (WWF) at a recent event on climate change, biodiversity, and livelihoods. Oglethorpe is the chief of party for the Hariyo Ban (Green Forests) Program, which seeks to increase ecological and community resilience to climate change in two biodiverse landscapes in Nepal. Taking a “multi-scale approach let[s] us focus on the most vulnerable people,” said Oglethorpe, and “work at different scales and across different disciplines…to reduce people’s vulnerability.”

As senior military officers, we see water stress—the lack of adequate fresh water—as a growing factor in the world’s hotspots and conflict areas, many of vital interest to the United States. Our earlier reports have identified a nexus among climate, water, energy, and U.S. national security. We have previously shown how emerging resource scarcity across this nexus can be a threat multiplier and an accelerant of instability. With escalating global population and the impact of a changing climate, we see the challenges of water stress rising with time. It is in this context that we now seek to provide a better understanding of the mechanisms through which water factors into violence and conflict.