NASA images reveal the extent of coastal collapse.

The U.S. East Coast faces a double whammy of water, according to NASA. Rising sea levels are already a concern, but new research shows the land itself is sinking, adding another layer of vulnerability to major cities like New York, Baltimore and Norfolk.

Scientists at Virginia Tech’s Earth Observation and Innovation Laboratory used satellite data and GPS sensors to find that parts of the coastline sank 1 to 2 millimeters per year between 2007 and 2020. While this may seem small, it adds to threatening water levels from rising sea levels, potentially putting critical infrastructure and millions of residents at greater risk of flooding and coastal hazards.

This research Highlights the complex challenges faced by coastal communities in coping with the impacts of climate change. Addressing sea level rise and land subsidence requires comprehensive adaptation strategies to ensure the long-term resilience of these areas.

Seawater erosion and land subsidence lead to forest displacement, affecting not only wildlife but also human structures. Along the coast, some 897,000 structures, including highways and airports, sit on land that is sinking.

The findings stem from a previous study by the EOI Laboratory, published in nature communications, using the same data, showed that most East Coast marshes and wetlands—critical for protecting many cities from storm surges during hurricanes—are sinking at a rate of more than 3 millimeters per year. They found that at least 8% of coastal forests have been replaced by land subsidence and saltwater intrusion, leading to a proliferation of “ghost forests.”

“Subsidence is a deleterious, highly localized and often overlooked problem compared with global sea level rise, but it is responsible for explaining many of the changes in the eastern U.S.,” said VA geophysicist Leonard Ohenhen. A major factor in rising water levels in the region.” Tech. Consequences for coastal residents include more “clear sky” tidal flooding, more damage to homes and infrastructure, and more problems with saltwater intrusion into farmland and freshwater supplies.