{"id":623167,"date":"2026-05-04T16:04:10","date_gmt":"2026-05-04T16:04:10","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/623167\/"},"modified":"2026-05-04T16:04:10","modified_gmt":"2026-05-04T16:04:10","slug":"plan-for-relocations-away-from-coastal-la-now-scientists-environment","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/623167\/","title":{"rendered":"Plan for relocations away from coastal LA now: scientists | Environment"},"content":{"rendered":"

A team of scientists led by a Tulane geologist is urging Louisiana to begin planning now for how to relocate entire communities<\/a> away from the coast, warning that sea levels may eventually rise high enough to overtake New Orleans.<\/p>\n

The paper, published Monday in the journal Nature Sustainability with Tulane coastal geologist Torbj\u00f6rn T\u00f6rnqvist as lead author, gives\u00a0a concrete picture of what southeast Louisiana could look like in the coming centuries as sea levels rise. The team identified, for the first time, an ancient shoreline about 30 miles north of New Orleans that marks where the Gulf of Mexico once reached.<\/p>\n

That finding underpins an argument the paper makes, one its authors acknowledge won’t be popular: that the state should begin planning now for a gradual, multi-generational relocation of coastal residents to higher ground. New Orleans, the paper argues, will eventually become \u201cphysically impossible\u201d to defend with floodwalls and levees.<\/p>\n

\u201cThey are saying out loud the things that no one wants to say,\u201d A.R. Siders, an associate professor at the University of Delaware who studies how people are adapting to climate change, said of the study\u2019s authors. \u201cNo one wants to say New Orleans won\u2019t be there in 200 years.\u201d Siders reviewed the paper but was not involved with the study.<\/p>\n

The argument isn\u2019t entirely new, and T\u00f6rnqvist has been warning about New Orleans’ long-term future for years. In a 2020 paper<\/a>, he wrote that Louisiana’s wetlands had crossed a tipping point and that the eventual shoreline would likely settle near the Baton Rouge Fault, a geological line where land to the south sinks faster than land to the north.<\/p>\n

What the new paper adds is direct geological evidence of where that shoreline once was, and a sharper policy stance from an interdisciplinary team that combines geology with archaeology, demography and policy. It\u2019s a perspective article, a format in which authors advance an argument supported by evidence rather than report a standalone research finding.\u00a0<\/p>\n

\u201cWhat is new about this study is that it lays out in clear scientific terms with abundant data and supporting information that we are facing right now a multi-generational need to relocate our coastal communities,\u201d said Sam Bentley, a professor of sedimentary geology at Louisiana State University who was not involved with the paper. \u201cThat has never been spelled out so clearly and with such urgency.\u201d<\/p>\n

Robert Young, a professor of geology at Western Carolina University who was not involved in the study, agreed with its findings but doubted they would move Louisiana’s political class.<\/p>\n

\u201cIt is going to be fairly straightforward for the political class to dismiss it because the timeframe is so long,\u201d he said. \u201cPoliticians are not going to get re-elected by telling communities that they need to leave.\u201d<\/p>\n

Not everyone in the region accepts the idea that the city might have to relocate. Greater New Orleans Inc., the regional economic development organization, said the paper goes too far in advocating for wholesale relocation of the city.<\/p>\n

\u201cThe study\u2019s findings are academically compelling, but empirically unconvincing,\u201d said Michael Hecht, the organization\u2019s president and CEO. \u201cExperience around the world, and here in Louisiana, demonstrates that relocation is not inevitable, nor always desirable.\u201d<\/p>\n

Finding an ancient shoreline<\/p>\n

The discovery happened almost by accident.<\/p>\n

About a decade ago, Tulane geologist Zhi-Xiong Shen \u2014 now at Coastal Carolina University and a co-author on the paper \u2014 was using lidar, a laser-based mapping technology, to study fault lines that contribute to southeast Louisiana’s sinking. He noticed a low, curving feature in the elevation data, drilled into the ground, and found sand: the remains of an ancient beach.<\/p>\n

That beach, now called the Ponchatoula Ridge, runs from roughly Mandeville in the east to Ponchatoula in the west. The sand had been shaped by wave action, indicating it is likely where the Gulf of Mexico lapped against the shoreline about 125,000 years ago, when the Earth was warmer than it was during most of human civilization. The shoreline from that period was known across much of the Gulf coast, but it was never located in Louisiana until now.\u00a0<\/p>\n

The discovery of the Ponchatoula Ridge is \u201ca small detail, maybe, to some readers, but the implications of it are epic,\u201d Bentley said. To him, it underscores that an area where more than a million people live will eventually be submerged.\u00a0<\/p>\n

Earth is now roughly as warm as it was during that last interglacial period, when temperatures peaked at as much as 2.7 degrees Fahrenheit above pre-industrial levels. Sea levels lag behind temperature, though, as ice sheets take centuries to melt, meaning the warming already locked in is expected to keep raising seas for centuries.<\/p>\n

That means the city could become a kind of fortified island in the Gulf by the time sea levels rise by roughly ten feet above where they are now, the study finds. And if sea levels rise by over 20 feet \u2014 a level the researchers say is locked in over the long term, though the timing is uncertain \u2014 sea water could slosh over the French Quarter\u2019s wrought-iron galleries.<\/p>\n

Current projections from the National Oceanic and Atmospheric Administration show seas rising off Louisiana by between 3.5 and 9 feet by 2100, depending on emissions scenarios.<\/a><\/p>\n

\"NO.LA2050.adv.122.JPG\"<\/p>\n

A photograph by Ted Jackson in 2007 is held at the site where the pictured U.S. Geological survey benchmark once stood at the surface of the water at the southwestern corner of Couba Island near St. Charles Parish, Friday, Sept. 8, 2023. The marker was installed on dry land in 1932. After Hurricane Ida, the marker was lost. An 8 foot metal pole was placed into the ground to indicate the depth. (Photo by Sophia Germer, NOLA.com<\/a>, The Times-Picayune) ORG XMIT: BAT2309081456571746<\/p>\n

STAFF PHOTO BY SOPHIA GERMER<\/p>\n

Fewer diversions, less time<\/p>\n

The state\u2019s recent cancellation of two major Mississippi River sediment diversions, the Mid-Barataria and Mid-Breton projects, both opposed by shrimpers and oyster farmers, has shortened the timeline.<\/p>\n

\u201cNew Orleans is in a terminal state,\u201d said Jesse Keenan, an associate professor at the Tulane School of Architecture and a co-author of the study. \u201cThe question is how much time do we have, and how much time can we buy?\u201d<\/p>\n

The U.S. Army Corps of Engineers, which built and maintains the post-Katrina levee system, is designing new additions to extend protection through 2073. Beyond that, the Corps said in a written response, \u201cadditional evaluations\u201d will be needed.<\/p>\n

Without the diversions, the city has less time,\u00a0T\u00f6rnqvist said. Future projects could buy some or all of that time back, though they will not change the eventual outcome.<\/p>\n

\u201cThe negative outcomes of continued sea level rise are just going to happen earlier,\u201d T\u00f6rnqvist said. \u201cThe time window to do this managed relocation is just going to be shortened by maybe a couple of decades. And that\u2019s a lot of time.\u201d<\/p>\n

\u201cThere\u2019s a kind of mortality here,\u201d Keenan said. \u201cWe\u2019re facing our own mortality with New Orleans, and that\u2019s fine. There\u2019s nothing wrong with that. It just means we have to think about palliative care and how we are going to treat those who are immobile and those that are getting left behind.\u201d<\/p>\n

The paper also argues that getting ahead of relocation could give New Orleans a \u201cfirst mover advantage,\u201d\u00a0or a chance to develop expertise other coastal cities will eventually need.\u00a0<\/p>\n

Young, the Western Carolina geologist, wasn\u2019t convinced that was really an advantage.<\/p>\n

\u201cThe main problem I have with the paper is at the very end when it talks about the possibility of making New Orleans and places south a model for what could happen elsewhere,\u201d he said. \u201cI\u2019m just really skeptical that that can happen anytime soon.\u201d<\/p>\n

Without a state-managed plan, the paper warns, residents with savings will leave first, taking the tax base with them and stranding lower-income residents in communities with eroding services and worsening climate hazards.<\/p>\n

\u201cThose people with abundant resources will move, and then who do you leave behind?\u201d Keenan said. \u201cA highly impoverished and immobile population.\u201d<\/p>\n

Articulating all of this and publishing it in a reputable scientific journal puts the researchers in a somewhat uncomfortable position, they said, having to tell people what they don\u2019t want to hear. T\u00f6rnqvist said he was \u201cpreparing for some hate mail.\u201d Keenan said he would not have published the paper if he didn\u2019t have tenure.<\/p>\n

\u201cMany of us have taken the approach that advocating for a particular stance can threaten our apparent objectivity in reaching a solution,\u201d said Bentley. \u201cBut sometimes you have to do it. And I think this is an exceptional case.”<\/p>\n","protected":false},"excerpt":{"rendered":"A team of scientists led by a Tulane geologist is urging Louisiana to begin planning now for how…\n","protected":false},"author":2,"featured_media":623168,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[47],"tags":[192,40197,8803,79],"class_list":["post-623167","post","type-post","status-publish","format-standard","has-post-thumbnail","category-environment","tag-environment","tag-fej","tag-hardwall","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/623167","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=623167"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/623167\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/623168"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=623167"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=623167"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=623167"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}