Rising seas and sinking cities signal a coastal crisis in China

A Rutgers study of geological records shows sea level increasing the fastest in 4,000 years, highlighting need for global and local action

Rutgers University

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The study's data shows that modern, global sea level rise is happening faster than at any time in the past 4,000 years.

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Credit: Yucheng Lin

A team of scientists led by Rutgers researchers has uncovered evidence that modern sea level rise is happening faster than at any time in the past 4,000 years, with China’s coastal cities especially at risk.

The scientists examined thousands of geological records from a number of sources, including ancient coral reefs and mangroves, which serve as natural archives of past sea levels. They reconstructed sea level changes going back nearly 12,000 years, which marks the beginning of the current geological epoch, the Holocene, which followed the last major ice age.

Reporting in Nature, their findings show that since 1900, global sea levels have risen at an average rate of 1.5 millimeters (or about one-sixteenth of an inch) a year, a pace that exceeds any century-long period in the past four millennia.

“The global mean sea level rise rate since 1900 is the fastest rate over at least the last four millennia,” said Yucheng Lin, who conducted the research as a postdoctoral associate at Rutgers and is a scientist at Australia’s national research agency, the Commonwealth Scientific and Industrial Research Organization in Hobart.

Lin studied with Robert Kopp, a Distinguished Professor with the Department of Earth and Planetary Sciences in the School of Arts and Sciences. “Dr Lin's work illustrates how geological data can help us better understand the hazards that coastal cities face today,” said Kopp, who also authored the study.

Two major forces, thermal expansion and melting glaciers, are driving this acceleration, Lin said. As the planet warms because of climate change, oceans absorb heat and expand. At the same time, ice sheets in Greenland and Antarctica are melting, adding more water to the oceans.

“Getting warmer makes your ocean take up more volume,” Lin said. “And the glaciers respond faster because they are smaller than the ice sheets, which are often the size of continents. We are seeing more and more acceleration in Greenland now.”

While rising seas are a global issue, China faces a unique double threat, he said. Many of its largest and most economically important cities, including Shanghai, Shenzhen and Hong Kong, are in delta regions, which are naturally prone to sinking because they were built above thick and soft sediments.

But human activities are making things worse.

“We’ve been able to quantify the natural rate of sea level rise for this area,” Lin said. “But human intervention, mostly groundwater extraction, makes it happen much faster.”

Subsidence refers to the gradual sinking or settling of the Earth's surface. It can happen naturally because of geological processes, or it can be caused by human activities, such as groundwater extraction.

To determine how sea level rise will adversely affect China’s deltas, the team examined a combination of geological records, subsidence data and human activity impacts across coastal regions, especially in the Yangtze River Delta and Pearl River Delta. These areas are home to several megacities.

In Shanghai, parts of the city sank more than one meter (about three feet) during the 20th century because of excessive groundwater use, Lin said. That is orders of magnitude faster than the current global sea level rise rate.

Delta regions are flat, fertile and close to water, making them ideal for farming, transportation and urban development. But their geography also makes them extremely vulnerable to flooding.

“Centimeters of sea level rise will greatly increase the risk of flooding in deltas,” Lin said. “These areas are not only important domestically, they’re also international manufacturing hubs. If coastal risks happen there, the global supply chain will be vulnerable.”

Despite the findings, Lin’s research offers hope, he said. Cities such as Shanghai have already taken steps to reduce subsidence by regulating groundwater use and even reinjecting freshwater into underground aquifers.

“Shanghai now is not sinking that fast anymore,” Lin said. “They recognized the problem and started regulating their groundwater usage.”

The study also provides vulnerability maps to help governments and city planners identify subsidence hotspots and prepare for future sea level rise.

Although the researchers focused on China, lessons from the study apply globally, Lin said. Many major cities, such as New York, Jakarta and Manila, are built on low-lying coastal plains and face similar risks.

“Deltas are great places, good for farming, fishing, urban development and naturally draw civilizations to them,” Lin said. “But they are really flat yet prone to human-caused subsidence, so sustained sea level rise could submerge them really fast.”

The paper is an application of PaleoSTeHM, an open-source software framework for statistically modeling paleo-environmental data that Lin developed as a postdoctoral associate.

Praveen Kumar, a postdoctoral associate in the Department of Earth and Planetary Sciences, also contributed to the study.

The National Science Foundation and NASA supported the research.

Explore more of the ways Rutgers research is shaping the future.

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Journal

Nature

DOI

10.1038/s41586-025-09600-z 

Method of Research

Data/statistical analysis

Subject of Research

Not applicable

Article Title

Modern sea-level rise breaks 4,000-year stability in southeastern China

Article Publication Date

15-Oct-2025

 

Study indicates dramatic increase in percentage of US adults who meet new definition of obesity

Mass General Brigham researchers studied a new definition of obesity that moves beyond BMI to include measures of body fat distribution

Mass General Brigham

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The prevalence of obesity in the United States could rise sharply under a new definition of obesity released earlier this year by the Lancet Diabetes and Endocrinology Commission. Researchers from Mass General Brigham found that when applying the new criteria, which expands upon the traditional use of body mass index (BMI) to include measures of body fat distribution, the prevalence of obesity increased from about 40 percent to about 70 percent among over 300,000 people included in their study. The rise was even more pronounced among older adults. Additionally, the researchers found that those newly added individuals also had a higher risk of adverse health outcomes. Their results are published in JAMA Network Open.

“We already thought we had an obesity epidemic, but this is astounding,” said co-first author Lindsay Fourman, MD, an endocrinologist in the Metabolism Unit in the Endocrinology Division of the Mass General Brigham Department of Medicine. “With potentially 70 percent of the adult population now considered to have excess fat, we need to better understand what treatment approaches to prioritize.”

Traditionally, obesity has been defined by BMI, which estimates body fat based on a person’s weight and height. But other anthropomorphic measures—such as waist circumference, waist-to-height ratio, or waist-to-hip ratio—may further account for fat distribution and aid in differentiation between muscle and fat mass.

Under the new framework, a person is classified as having obesity if they have a high BMI plus at least one elevated anthropometric measure (a condition the authors term “BMI-plus-anthropometric obesity”), or if they have a normal BMI and at least two elevated anthropometric measures (a condition termed “anthropometric-only obesity”). The new definition also distinguishes between preclinical and clinical obesity with clinical obesity defined as the presence of obesity-related physical impairment or organ dysfunction. At least 76 organizations have endorsed the new guidelines, including the American Heart Association and The Obesity Society.

The study analyzed participants in the National Institutes of Health All of Us Research Program’s cohort of over 300,000 Americans. Obesity prevalence was 68.6 percent with the new definition, versus 42.9 percent under the traditional BMI-based definition. This increase was entirely driven by inclusion of individuals with anthropometric-only obesity. Obesity rates varied by sex, race, and especially by age—affecting nearly 80 percent of adults over 70.

Importantly, the study found that those with anthropometric-only obesity – who would not have been classified as having obesity by the traditional definition – had a higher risk of diabetes, cardiovascular disease, and mortality than people without obesity. About half of all individuals who met the new obesity criteria had clinical obesity, and this proportion was only slightly lower in the anthropometric-only obesity group compared with the BMI-plus-anthropometric obesity group.

“We have always recognized the limitations of BMI as a single marker for obesity because it doesn't take into account body fat distribution,” said senior author Steven Grinspoon, MD, Chief of the Metabolism Unit in the Endocrinology Division of the Mass General Brigham Department of Medicine. “Seeing an increased risk of cardiovascular disease and diabetes in this new group of people with obesity, who were not considered to have obesity before, brings up interesting questions about obesity medications and other therapeutics.”

The researchers emphasize that further studies are needed to better understand the causes of and optimal treatments for anthropometric-only obesity. The research team previously developed a therapeutic that reduces waist circumference and plans to explore the utility of different treatment strategies in this newly defined population.

“Identifying excess body fat is very important as we’re finding that even people with a normal BMI but with abdominal fat accumulation are at increased health risk,” Fourman said. “Body composition matters – it’s not just pounds on a scale.”

Authorship: In addition to Fourman and Grinspoon, Mass General Brigham authors include Aya Awwad, Camille A. Dash, Julia E. Johnson, Allison K. Thistle, Nikhita Chahal, Sara L. Stockman, Mabel Toribio, Chika Anekwe, and Arijeet K. Gattu. Additional authors include Alba Gutiérrez-Sacristán.

Disclosures: Fourman serves as a consultant to Theratechnologies and Chiesi Farmaceutici and receives grant funding to her institution from Chiesi Farmaceutici outside of this work. Grinspoon serves as a consultant to Marathon Assets Management and Exavir Therapeutics and receives grant funding to his institution from Kowa Pharmaceuticals, Gilead Sciences, and Viiv Healthcare, unrelated to this project. For the remaining authors, no conflicts were declared.

Funding: This work was supported by the National Institutes of Health (grants K23HD100266, 1R01AG087809, T32DK007028, K23HL147799, 1R01HL173028, and P30DK040561) as well as the American Heart Association-Harold Amos Medical Research Faculty Development Program, supported by the Robert Wood Johnson Foundation, and the Robert A. Winn Excellence in Clinical Trials Award Program from the Bristol Meyers Squibb Foundation. The funding organizations played no role in the design and conduct of the study, collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.

Paper cited: Fourman LT et al. “Implications of the Lancet Commission Obesity Definition Among the All of Us Cohort” JAMA Network Open DOI: 10.1001/jamanetworkopen.2025.37619

About Mass General Brigham

Mass General Brigham is an integrated academic health care system, uniting great minds to solve the hardest problems in medicine for our communities and the world. Mass General Brigham connects a full continuum of care across a system of academic medical centers, community and specialty hospitals, a health insurance plan, physician networks, community health centers, home care, and long-term care services. Mass General Brigham is a nonprofit organization committed to patient care, research, teaching, and service to the community. In addition, Mass General Brigham is one of the nation’s leading biomedical research organizations with several Harvard Medical School teaching hospitals. For more information, please visit massgeneralbrigham.org.

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Journal

JAMA Network Open

DOI

10.1001/jamanetworkopen.2025.37619 

Method of Research

Randomized controlled/clinical trial

Subject of Research

People

Article Title

Implications of the Lancet Commission Obesity Definition Among the All of Us Cohort

Article Publication Date

15-Oct-2025

COI Statement

Disclosures: Fourman serves as a consultant to Theratechnologies and Chiesi Farmaceutici and receives grant funding to her institution from Chiesi Farmaceutici outside of this work. Grinspoon serves as a consultant to Marathon Assets Management and Exavir Therapeutics and receives grant funding to his institution from Kowa Pharmaceuticals, Gilead Sciences, and Viiv Healthcare, unrelated to this project. For the remaining authors, no conflicts were declared.

 

WSU study finds positive framing can steer shoppers toward premium products

Washington State University

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PULLMAN, Wash. -- Consumers are more likely to choose a higher-priced item when it’s correlated with messages that emphasize an increase in the product’s positive attributes—rather than a reduction in its negative ones.

When deciding between two products, consumers don’t just compare costs, they also respond to how the relationship between the cost and product attributes is described. A new Washington State University study shows that people perceive a stronger link between price and product attributes when the relationship is framed positively.

For example, researchers presented the following scenario between the price of two pre-owned electric vehicles and their battery capacities: The first vehicle had 80% battery capacity remaining and cost $40,000, while the second had 90% capacity remaining and cost $45,000. The battery information could also be stated in terms reflecting how much battery capacity had been lost (20% vs. 10%, respectively).

The presentation offers the same information—battery capacity in relation to price—but participants were more likely to see the higher-priced vehicle as a better value when the relationship was presented as moving in the same direction, i.e. as battery capacity increases, so does the vehicle’s price.

Kunter Gunasti, associate professor of marketing in WSU’s Carson College of Business and coauthor of the study, calls this effect “relationship sign framing.”

“In simple terms, when price and product attributes are described as moving together, each extra dollar feels like it buys more benefit,” he said. “When they are described as moving in opposite directions, the connection feels weaker, nudging people toward the cheaper option. People naturally find positive relationships easier to process.”

To test the effect, the researchers ran the battery capacity experiment and several others, including evaluating new bike helmets. One scenario described the helmets in terms of the “percent of impact absorbed” (a positive relationship with price: more absorption, higher cost). The other described them by the “percent of impact transmitted to the head” (a negative relationship: less transmission, higher cost).

Gunasti said the helmets were added to show the effect applies to new as well as used products and in different product categories. Across both studies, positive framing increased preference for the higher-quality, higher-priced option.

Results were even stronger for items people bought for enjoyment, such as vacations, luxury clothing, or sports cars. In those cases, shoppers focused more on what they were gaining, which aligned with positive relationship framing effect. For practical items like dish soap, tires, or dishwashers, people paid closer attention to what they were spending, which weakened the effect.

The findings offer practical lessons for marketers. Premium brands stand to gain from framing attributes in positive terms, emphasizing how more of something justifies a higher price. Budget brands, by contrast, may benefit from negative framing that makes the link between price and product attributes feel weaker.

The research also carries lessons for everyday shoppers. According to Gunasti, positive framing doesn’t mean a product is actually better, it just changes how people perceive the value—and he advises consumers to pause and flip the description in their minds.

“If you see a positive frame while comparing two products, try thinking about how it would look in negative terms. And if you see a negative, consider the positive version,” he said.

“Looking at both sides helps you make a more informed decision.”

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Journal

Nature

DOI

10.1007/s11002-025-09785-3 

Method of Research

Experimental study

Article Title

Relationship-sign framing: The sign of attribute relationships influences product preference via perceived relationship magnitude

 

How grandparents can play a critical role in mediating children’s media use

A Rutgers researcher said initial findings from a study offer “various compelling insights” into the process of socializing children to what they see on their screens

Rutgers University

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Grandparents can play a critical role in helping mediate their grandchildren’s media use and serve as an ally for their families, according to a Rutgers study.

 

Researchers found that grandparents often monitor media use by using strategies or instructions provided by another caregiver, most commonly the child's parents. The researchers coined this process "secondary mediation.”

 

"Our initial findings offer various compelling insights into this critical process of socializing children to media use," wrote the authors of the study, Dafna Lemish, a Distinguished Professor of Journalism and Media Studies at the Rutgers School of Communication and Information, and Galit Nimrod and Nelly Elias, both professors at Ben-Gurion University of the Negev, Israel.

 

Based on the study, published in the Journal of Aging Studies, the authors suggested that mediation theory should be modified to include secondary mediation of other caregivers.

 

“Moreover, our findings are also highly relevant to the understanding of intergenerational relationships,” the authors wrote.

 

Their research is part of a larger study that may be the first to offer an in-depth investigation into the involvement of grandparents in mediating children's media use.

 

“There is a lot of research on how parents mediate the use of their children’s media by applying a variety of strategies, such as restricting the amount of screen time, supervising the content children are engaged with, actively discussing media use, and co-viewing and co-playing with them,” Lemish said. “But little attention has been paid to the role of grandparents who regularly care for their grandchildren. Are grandparents also engaged in mediating media use? Do they follow some rules set by the parents? Do they tend to ‘spoil’ their grandchildren by taking a more lenient approach to their media use? As a grandmother myself, I felt particularly drawn to these questions.”

 

Understanding the role grandparents play in mediating children’s media use is important, Lemish said, "because there is substantial evidence about the potential impact of media on children.”

 

Lemish added grandparents can help minimize the negative potential (violence, alienation, bullying, misinformation, commercial exploitation and gender and racial stereotypes) and maximize the positive potential (enrichment, learning, cognitive-social-emotional development and enjoyment).

 

It is also important that parents and grandparents share similar approaches to media use, reinforce each other, and avoid creating internal conflicts, Lemish said.

 

The authors said the degree to which grandmothers follow the requests from mothers or whether mothers listen to the advice provided by grandmothers "depends on a host of characteristics and circumstances and is not a straightforward application of rules transmitted from one caregiver to another."

 

The researchers found it depends on the nature of the relationship between the mother and the grandmother, their experience and comfort with the media, their level of education and the time the grandmother spends caregiving for the grandchildren.

 

The researchers distinguished between noninteractive uses (watching films, YouTube videos and television programs on any screen) and interactive (playing digital games and online activities other than watching) and found that grandparents were more likely to mediate their grandchildren's exposure to noninteractive media.

 

To conduct the study, the researchers surveyed 267 pairs of grandmothers and mothers of 4- to 8-year-old children who agreed to participate in the study. The grandmothers were interviewed by phone and the mothers received an online link to the same survey.

 

“I recommend talking with each other about your views on the role of media in your children’s lives and create shared understanding and values about media consumption that takes into consideration the characteristics of the child, the circumstances; and the content of the media,” Lemish said. “Agree on what rules related to media consumption you would like to apply, and also on the circumstances when there could be some deviation from them.”

 

Explore more of the ways Rutgers research is shaping the future.

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Journal

Journal of Aging Studies

DOI

10.1016/j.jaging.2025.101357 

Method of Research

Survey

Subject of Research

People

Article Title

Secondary mediation of children's media use: An exploration of mothers-grandmothers' mediation dynamic☆