Source: Earth’s Future

Coastal landscapes are constantly being reshaped by natural forces, and as climate change causes more frequent storms and sea level rise, that change will only intensify. Because these areas are densely populated with homes, tourist destinations, and industries, understanding how and where the coast will change is a pressing issue. However, reliable predictions that lead to actionable knowledge are rare.

Lentz et al. describe the state of knowledge regarding coastal evolution, highlight gaps in scientists’ understanding, and describe opportunities for integrating information from various models, data sources, and end users.

Current coastal evolution predictions are often focused on too specific a location and are therefore hard to generalize or analyze too large a region and therefore lack detail, the authors say. In addition, it’s challenging for researchers to link the effects of acute events, such as storms, with long-term trends like sea level rise.

Improving these simulations will likely require combining many different types of models, including physics-based numerical models, models based on empirical measurements, and statistical models that include machine learning. To fully understand potential changes, the authors note that it is also essential to consider both coastal processes and human actions.

The researchers recommend several ways to improve consistency and collaboration in the field of coastal change forecasting. First, standardizing approaches and outcomes would make it easier to produce national-scale predictions. Right now, the variety of tools used across different locations makes it difficult for scientists to compare results and communicate effectively. They also emphasize the need for using coordinated research approaches. Stronger transdisciplinary collaboration, accompanied by essential training and support, would also enable scientists to make better predictions, the researchers say.

Comparing predictions to real-world observations of coastal landscape change could also help untangle this multifaceted challenge. By studying how coastlines have already changed, researchers can validate models and choose those that are performing best. Such comparisons require datasets that adequately capture coastal landscape change across both time and space. Remote sensing data and the use of artificial intelligence (AI) for data processing may help provide these improved datasets, the researchers suggest.

Engaging end users during the project planning process is also helpful because only end users truly know what kind of information they need to adapt to landscape change. Knowing how to engage end users can be difficult for physical scientists, but various tools and specialized personnel exist who can help coordinate these interactions, the authors say. (Earth’s Future, https://doi.org/10.1029/2024EF005833, 2026)

—Saima May Sidik (@saimamay.bsky.social), Science Writer

Citation: Sidik, S. M. (2026), How to study coastal evolution, Eos, 107, https://doi.org/10.1029/2026EO260115. Published on 15 April 2026.

Text © 2026. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.

Research & Developments is a blog for brief updates that provide context for the flurry of news that impacts science and scientists today.

Sand is the most exploited solid natural resource on Earth. It has been integrated into how we build homes, roads, buildings, and bridges as well as how we protect coastal infrastructure from rising seas. Sand underpins nearly every aspect of modern infrastructure and economics, plays crucial roles in supporting ecosystem biodiversity, and literally shores up rivers and coasts.

A new report from the United Nations Environment Programme (UNEP) found that we are using 50 billion metric tons (50 trillion kilograms) of sand per year. As global development and industrialization expand, demand for sand in the building sector is expected to rise 45% by the year 2060, outpacing current efforts to sustainably harvest it. The report’s authors urge countries to establish sand as a strategic national asset and develop policies for sustainable extraction.

“Sand is sometimes referred as the unrecognized hero of development, but its essential role in sustaining the natural services on which we depend is even more overlooked,” Pascal Peduzzi, director of the UNEP Global Resource Information Database Geneva, said in a press release about the report. “Sand is our first line of defence against sea level rise, storm surges, and salination of coastal aquifers—all hazards exacerbated by climate change.”

Sand Wanted: Dead or Alive

Dead sand, or sand that has been extracted from its natural environment, is a key component in building materials like concrete and asphalt. Communities around the world use sand in water filtration systems, providing clean water for drinking and agricultural use. And although a transition to clean energy sources is necessary to curb the effects of climate change, many of those sources also depend on sand: solar panels require glass made from high-purity silica sand, and wind turbines, hydroelectric dams, and nuclear power plants all require concrete.

Sand also plays a critical role in natural ecosystems. It is home to a wide array of critters from crabs, sharks, and turtles to microorganisms like bacteria and fungi. It supports the growth of corals, mangroves, and seagrasses that in turn support even more marine creatures. It is a key component of healthy soil and aids in surface drainage. It guides river evolution and acts as flood buffer and storm barrier. It also provides local economic benefits via tourism.

These are among the values of sand when it is left alone and unused, called “alive” sand. The UN report notes that these benefits are typically of greater value over time than if sand is dredged and used. But because these benefits are hard to see, they are often overlooked when nations calculate the value of their sand resources.

A Sustainable Sand Future

Despite sand’s importance whether dead or alive, the report notes that few countries have established sand as a strategic national asset or have developed strategies for sustainable extraction. At the current pace, humans are extracting sand from the natural environment at a faster pace than it is being replenished by geologic processes.

What’s more, the UNEP’s Marine Sand Watch tool shows that about half of sand dredging companies are operating within marine protected areas, accounting for about 15% of the volume of dredged sand. This practice, the report notes, is potentially trading in sand’s long-term benefits for short-term gains.

The UN report recommends a few actions to protect the long-term availability of sand as a natural resource, including:

• Recognizing sand as strategic national asset, establishing national inventories, and creating long-term regional planning groups that consider sand as an essential resource for resilience;
• Establishing circularity and recycling of building materials, especially in areas of conflict and natural disasters;
• Strengthening environmental protection practices, and codifying international frameworks to strengthen accountability along the supply chain, including increased transparency about extraction; and
• Integrating sand-related biodiversity and social risks into financial decisionmaking and governance.

“Over-reliance on short-term economic metrics risks obscuring, and further impacting, the geological and ecological processes that take centuries to form and may not be restored once critical thresholds are crossed,” the report states. “What is hardest to measure may be precisely what sustains both nature and human societies over the long term. The challenge ahead is not only to manage extraction, but to recognise and balance the full spectrum of sand’s values.”

—Kimberly M. S. Cartier (@astrokimcartier.bsky.social), Staff Writer

These updates are made possible through information from the scientific community. Do you have a story about science or scientists? Send us a tip at eos@agu.org.

Text © 2026. AGU. CC BY-NC-ND 3.0
Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.