As humans continue to dump greenhouse gases into the atmosphere, the resulting climate change causes sea levels to rise. Given that New York City is on average less than three yards above sea level, America's largest metropolis is vulnerable to sea level rise, which will cause widespread flooding. Yet this process will be worsened by the vertical motion of the land itself, according to a recent study published in the peer reviewed journal Science Advances.
Using remote sensing technology, researchers from NASA's Jet Propulsion Laboratory in Southern California and Rutgers University in New Jersey studied the upward and downward motion of New York City's land from 2016 and 2023. This so-called uplift and subsidence was only partially caused by natural variables, such as the earth in that region sinking back down after the last ice age. Human activity, such as constructing landfills and reclaiming land, also significantly contributes to subsidence.
Overall the NASA scientists learned that the New York City metropolitan area subsides by an annual average of 0.06 inches (1.6 millimeters), roughly equivalent to the monthly growth of a human toenail. Some areas are subsiding more quickly: For example Arthur Ashe Stadium, the world's largest tennis stadium, is sinking at a rate around 0.18 inches (4.6 millimeters) per year. While this may seem like a small amount, it does add up and is predicted to even accelerate as climate change worsens.
"Our results inform ongoing efforts to adapt to sea level rise and reveal points of [vertical land motion] that motivate both future scientific investigations into surface geology and assessments of engineering projects," the authors conclude.