Accelerating Sea Level Rise Threatens Southeastern United States’ Coasts and Infrastructure

According to the most recent data, millions of inhabitants established near the coasts are likely to experience climatic variations – including hurricanes – more devastating than those of previous decades. Big cities like Houston, Miami, Charleston and New Orleans are at risk.

More concretely, the water level bordering the coasts of the American Southeast and those of the Gulf of Mexico would have risen by 12.7 cm since 2010, indicates a recent study by the University of Arizona. This increase is much greater than the average of previous decades.

“This whole region is feeling the impacts of this phenomenon,” the minister said. Washington Post the author Jianjun Yin, professor of geosciences. The water level recorded after the passage of the hurricane Ian [septembre 2022] is a record attributable to the combination of high sea level and storm surge. »

The passing ofIanit should be remembered, devastated part of the west coast of Florida, leaving damage estimated at 113 billion US.

Another study by the National Oceanic and Atmospheric Administration (NOAA), a federal agency, also indicates an average sea level rise of 0.5 in (1.27 cm) per year between 2010 and 2022 in the Pensacola, Florida area. In comparison, the recorded average was 1/12 inch (0.21 cm) per year between 1923 and 2009.

The Washington Post nevertheless adds that the findings made over a relatively short period (2010-2022) leave some scientists skeptical. “Usually, researchers prefer to rely on data spanning decades,” they say.

“It is obvious that we must remain cautious about the generalization of a trend observed over only a dozen years”, indicates, in an exchange of e-mails, Pascale Biron, full professor in the department of geography, urban planning and environment of the ‘Concordia University.

It indicates that certain “natural variability” must be taken into account, such as the phenomenon of The girl which can “cause a drop in sea levels”.

M^me Biron also refers us to recent NASA research concluding that over the past 30 years, the rise in sea level caused by human activities has been 10 times greater than the natural rise.

INSERT NASA GRAPHIC HERE

Canada, which has 226,000 km of coastline, is not spared. For example, a document from the Geological Survey of Canada published in 2021 indicated that the level of the oceans could rise by 175 cm by 2100 in certain regions.

Communities react

Professor at the Faculty of Planning of the University of Montreal and specialist in urban vulnerability, Isabelle Thomas does not find “very much innovative” in the new studies, indicating that we already know that “these territories suffer of subsidence”.

On the other hand, she believes that “very interesting initiatives have been taken” on the redevelopment of cities, the types of buildings and the types of practices so that “citizens adapt to possible floods”.

She gives an example of the case of New Orleans, where she lived and taught and which learned lessons following the devastating passage of the hurricane. Katrinain August 2005. Among the green and blue infrastructures put in place to prevent further flooding, M^me Thomas mentions the Gentilly district, one of whose parks, Mirabeau Water Garden, can retain and drain more than 10 million gallons (37.8 million liters) of hurricane water.

Another trial program offers land swaps for residents in high-risk areas.

That’s all good, but shouldn’t we just leave the coast and return it to nature? “It’s a very relevant question that we ask ourselves,” replies M.^me Thomas. The problem is that we have urbanized our coasts a lot! If we do buy-back programs, it is very important that they be in collaboration with citizens to give them the possibility of relocating to pleasant places. For families who have given themselves homes from one generation to the next, it is important to get it right. »

With The Washington Post et The New York Times

Colorado River: Washington could intervene

Washington could make a unilateral decision next summer to force seven Southwestern states to adopt a plan to reduce water use from the Colorado River. The river supplies nearly 40 million Americans and two states in Mexico, in addition to irrigating some 5.5 million acres of agricultural land. However, the water level of the river is so low that there is a real risk that the water will no longer flow beyond large dams. The Department of the Interior has been asking the states concerned for months to agree on a plan to reduce consumption. However, California, the largest consumer and state with precedence, does not get along with its neighbors, in particular Nevada and Arizona. Washington could decide in favor of California, a great garden that feeds America. But the Biden administration cannot alienate Arizona and Nevada, two pivotal states for the re-election of a president and Democratic senators in 2024, reports the New York Times. One thing is certain, if the federal government decides, it will be a first in American history.