Combating sea level rise without reducing humanity’s carbon footprint is like trying to drain a bathtub without turning off the faucet. But scientists are sounding the alarm about another problem that is exacerbating the crisis in coastal cities. It means the land is also sinking, a phenomenon known as subsidence. As rapid global warming turns more and more polar ice into seawater, the metaphorical faucet is still running, while the bathtub is sinking to the floor.
surprising new facts study in a diary Nature It shows how serious this problem can be in 32 coastal U.S. cities.Previous predictions have been studied earth-centered Sea level rise, or how much the ocean is rising along a particular coastline. This new study thinks that: Relative Sea level rise also includes vertical movement of land. That’s possible thanks to new data from satellites that can measure elevation changes along coastlines at very fine scales.
With this subsidence in mind, studies show that by 2050, an additional 500 to 700 square miles of land will be flooded in coastal areas of the United States, an additional 176,000 to 518,000 people will be affected, and up to 100 billion more people will be flooded. It turns out that property damage of $1.00 could occur. This is on top of previous baseline estimates of damage through 2020, which affected between 530 and 790 square miles, affected between 525,000 and 634,000 people, and cost between $100 billion and $123 billion. .
Overall, the study found that 24 of the 32 coastal cities surveyed were sinking by more than 2 millimeters per year. (One millimeter is equivalent to 0.04 inch.) “Both land subsidence and sea level rise combine to create a compounding effect of human exposure,” said the study’s lead author, Dr. said Leonard Owenhen, an environmental security expert at Virginia Tech. “When you combine both, you create an even greater danger.”
The problem is that cities have built seawalls and other structures to prepare for predicted sea level rise caused by ground motion. Considering the early days of satellite land subsidence monitoring, through no fault of their own, they have overlooked half the problem. “All of the adaptation strategies we have right now are based on sea level rise,” says Manuchel Shirzai, an environmental security expert at Virginia Tech and co-author of the study. “This means that most, if not all, of these adaptation strategies overestimate how long they will be able to withstand the extreme consequences of sea level rise. But in some cases, it’s only 10 years.”
Land subsidence can occur naturally, such as when loose sediment settles over time, or it can be caused by human activity, such as when cities pump so much groundwater that aquifers collapse like empty water bottles. It may also occur due to In extreme cases, the following consequences may occur: Tens of feet of subsidence. The weight of coastal cities like New York is also pushing down on the ground, leading to further subsidence.
Courtesy of Leonard Owenhen, Virginia Tech
