Millions of people around the world live near river deltas— geographic areas that form at or below sea level. And those millions are at high risk of experiencing tropical storms, flooding and other impacts from climate change, according to a new analysis by Indiana University researchers. River deltas are found in cities such as New Orleans, Bangkok, and Shanghai. Decades of engineering have expanded river deltas, but they’ve also starved the regions of flood-preventing sediment. Without sediment being renewed naturally, the delta shorelines recede, worsening the impacts of storm surges, which are expected to occur more frequently due to sea-level rise and coastal flooding related to climate change. According to the IU study, of the 339 million people living on deltas throughout the world, 31 million of these people are living in 100-year storm surge floodplains. To make matters worse, 92 percent of those 31 million live in developing or least-developed economies. As a result, some of the most disadvantaged populations are most at-risk. IU professor Eduardo Brondizio, who has been working with communities in the Amazon delta for three decades, says these communities are already dealing with many risks including poverty and lack of sanitation and services. “Climate change is exacerbating all of these issues and creating more impacts,” he says. To better prepare for more intense coastal flooding, we need better models to more accurately predict exposure and risk, the researchers say. “River deltas present special challenges for predicting coastal floods that deserve more attention in discussions about the future impacts of climate change,” says Brondizio.
Another area in dire need of attention is space--outer space, that is. The final frontier is getting very messy. Debris—including abandoned fuel tanks, tools dropped by astronauts, fragments from satellite collisions and more—is in orbit around the Earth. Right now, there are more than 128 million pieces of debris smaller than a half inch in orbit, and some 34,000 pieces of large debris. A new project co-led by IU professor Scott Shackelford is tackling how to manage the problem of space’s mess. Space junk is a critical problem for many reasons, Shackelford says, not the least of which is that our society relies on satellites for Internet service, weather forecasting, communication systems and much more. Those satellites can be damaged by debris. “Junk interferes,” Shackelford says. And the problem is only getting worse as dozens of countries now have space capabilities, along with private companies such as SpaceX. Shackelford and Jean-Frédéric Morin, professor at Université Laval in Québec, are creating a census identifying all the organizations and institutions that own or operate objects in Earth’s orbit. Once the census is complete, the researchers will analyze the data to more fully understand who outer space stakeholders currently are, how these space actors interact, and what can be done better. From there, they’ll move to focus on solutions and policy implications. “Now is the time to be exploring issues related to sustainably developing space and how we should govern the final frontier,” Shackelford says.