Land Subsequentence and Sea Level Rise in the United States: How Many Million Dollars Are Needed? Comment by Leonard Ohenhen and Eric Lindsey

Overall, the study finds that 24 of the 32 coastal cities studied are subsiding by more than 2 millimeters a year. (One millimeter equals 0.04 inches.) Leonard Ohenhen, the study’s lead author, says that the sinking of the land and the rise of the sea lead to exposure for people. You have a more severe hazard when you combine both.

Cities need to prepare for the double whammy, the researchers contend. The problem is twofold — sinking cities and rising seas — so solutions have to be twofold, as well.

“It’s something that is not so far off. Leonard Ohenhen is the lead author of the study and a PhD candidate at Virginia Tech. We hope that every stakeholder in the community discussion is able to think about how we will respond to future changes.

Eric Lindsey, an assistant professor at the University of New Mexico who has studied land subsidence and sea level rise, was not involved in the paper, but he thinks it will be useful to the communities that will be affected.

Land subsidence can be natural or human-made and can be stopped with the help of steps. Land sink due to pumping water, oil and gas out of the ground. The sinking slows if you stop drilling and pumping.

You can even reverse some of the damage by replenishing aquifers. Manoochehr Shirzaei, who is also the director of the Earth Observation and Innovation Lab at Virginia Tech, says the solutions to the problem of land subsidence are readily available.

Since greenhouse gas emissions from fossil fuels are causing climate change, leaving fossil fuels in the ground is also a solution to sea level rise. Sea walls and levees are not enough. Even with current defenses in place, an additional 1,389 square kilometers of land along US coasts could be threatened by sea level rise by 2050.