When Secretary of the Navy Richard Spencer told the media last week that “the damn thing melted,” he wasn’t talking about an ice cream cone. As the Arctic faces unprecedented levels of open water, Spencer and other naval leaders recently testified to Congress about the U.S. Navy’s strategy, which is changing as quickly as the Arctic itself. 

Plastics. From the devastating effects of plastic pollution on our oceans, to the news that plastic bottles likely pollute the drinking water they contain, plastic pollution—the theme of this year’s Earth Day—has been a highly visible issue, and we’ve seen some notable progress on fighting the plastic battle.  

Food has long been used by countries to wage both war and peace, and the post-war era of American food dominance is no exception. Bryan McDonald, a professor at Pennsylvania State University, traces the United States’ “Food For Peace” strategy in his recent book, Food Power: The Rise and Fall of the Postwar American Food System, arguing that “food was central to national security” during this period.

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.

To further its goals to strengthen the global economy, China has already invested $300 billion of its pledged $1 trillion towards its Belt and Road Initiative—a massive infrastructure investment plan that spans 60 countries across Southeast Asia, Central Asia, Africa, South Asia, the Middle East, and Eastern Europe. China’s initiative will shift the world’s political, environmental, and economic landscape.

The first U.S. city to host a docked bike-share system, Washington, D.C., is now home to a rapidly growing influx of dockless bikes, with five companies vying for the market. The docked system still accounts for 87 percent of the shared bikes in the United States, but the number of dockless bikes—which can be located by riders using an app and then left anywhere—is growing rapidly. The data from these location-enabled bikes provide a unique opportunity to measure the point-to-point transportation needs of millions of people in some of the world’s densest cities.

A threat looms on the sun-splashed horizon of the Republic of the Marshall Islands. The specter of climate change wraps its fingers around the islands, raising sea levels, salinizing soils, and sapping freshwater resources. These changes will make it even harder to sustain crops, which could push the population to even greater reliance on  processed foods, which has already spurred a diabetes epidemic on the islands. The major role played by the United States in the history of the Marshalls, where nuclear bombs were famously tested during the Cold War, may continue, as the impacts of another existential threat—climate change—continue to increase.

The devastation in Puerto Rico is shocking: Half of the population, or 3.4 million people, lack drinking water and 95 percent are without electricity even two weeks after Hurricanes Irma and Maria.