Monday, April 27, 2026

 

Q&A: Does nature have a role in national security?




Penn State






UNIVERSITY PARK, Pa. — The security of every nation faces an increasingly severe and frequent threat: disruptions to nature. According to Bradley J. Cardinale, professor in the Department of Ecosystem Science and Management in the Penn State College of Agricultural Sciences, disrupted ecosystems can lead to increased risk for food security, water availability, health and well-being, as well as crime.  

Cardinale, along with collaborators J. Emmett Duffy, marine biologist and chief scientist for the Smithsonian Environmental Research Center, and Rod Schoonover, ecological security expert who was a former director for the U.S. National Intelligence Council and adjunct professor in the School of Foreign Service at Georgetown University, published an assessment of 27 case studies on how disrupted ecosystems can heighten risks of societal unrest and political instability, ultimately threatening national security, in the journal Nature-Based Solutions.  

In the Q&A below, Cardinale discussed nature’s role in national security, as well as how governments can best protect against ecological disruptions. 

Q: What is nature’s role in national security?  

Cardinale: We have long known that ecosystems and the creatures that live in them provide goods and services to people. These have been referred to as “ecosystem services” or “nature’s benefits to people.” Examples include provisions like food, wood and water; mitigating impacts of climate and disease; cultural benefits, such as recreation; and support for other life-support processes, like nutrient cycling.  

In this paper, we extend these concepts to the scale of entire countries by looking at how nature influences the ability of a nation to protect its citizens, institutions and interests from domestic and foreign threats. We draw explicit links between biological forms of global change that disturb ecosystems — what we call ecological disruptions — and increased risk in five areas of national security: food security, water scarcity, health security, protection from natural disasters and environmental crime. For each aspect, we show how ecological disruptions increase social and political stress that, in turn, undermine national security.  

Q: What are ecological disruptions, and how are they caused? How do they impact national security?  

Cardinale: Ecological disruptions are intense, rapid changes to the natural or semi-natural environment that significantly alter the structure, function and biodiversity of ecosystems. Ecological disruptions are often caused by humans, such as when our activities degrade or destroy ecosystems or threaten the species that live in them. 

In this paper, we consider five types of ecological disruption, including habitat loss, overharvesting, pest and disease outbreaks, invasive species, and biodiversity loss. We discuss how these ecological disruptions generate social and political stress, as well as provide 27 well-documented case studies showing how disruptions lead to mass migrations of people, border breaches, violent protests, regional conflict, even warfare. 

Our case studies include some well-known examples like the Cod Wars that occurred after overharvesting of cod led commercial trawlers to ignore international boundaries to fish for declining stocks. The result was a military conflict between Iceland and Britain. Examples of other case studies we review include deforestation exacerbating drought and water scarcity leading to violent protests in South America, invasive species causing crop failures and famine leading to mass migration and border breaches in Africa, mismanagement of wildlife causing pandemics of infectious disease that have led to civil disorder and violent protests globally, and illegal logging and wildlife poaching that has funded drug cartels, terrorist organizations and crime syndicates in several regions around the world.   

Q: How can people protect against ecological disruptions?  

Cardinale: It would be easy to suggest that individuals can protect against ecological disruptions by conserving and restoring nature. But this recommendation would be woefully inadequate due to a mismatch in scale. The ecological disruptions we are talking about — and the implications these disruptions have for security — are national and international in scale. As such, addressing the problem requires intervention by whole governments. 

We argue in this paper that governments should build and protect natural infrastructure in the same way they build and protect physical infrastructure. Governments already understand the important role of physical infrastructure like energy grids, transportation and communications networks, and water and food systems for national security. Indeed, we go to great lengths to protect physical infrastructure from bad actors and enemies during a conflict. In contrast, most governments are just beginning to appreciate the important role of natural infrastructure — the ecosystems and biological communities that are required to meet basic human needs and prevent ecological disruptions. 

Unfortunately, just as many nations are coming to appreciate the role of nature in maintaining natural security, others are actively dismantling the agencies, scientific expertise and investments necessary to understand changes in, and therefore safeguard, critical natural infrastructure. Weakening these institutions has the potential to undermine a nation’s ability to meet the basic needs of its citizens, fueling grievances that erode trust in government and heighten instability within and among nations.  

Q: What’s next for your work in this area?  

Cardinale: There are two directions we are going at present. First, we are trying to gather more examples of how nature impacts national security. If we can get a more case studies, including a more diverse representation of national security impacts, then we can transition into the next phase of quantitative data analysis where we determine which aspects of nature most impact security and compare the role of nature to other drivers of national security. 

Second, we are building a community of practitioners who will work together at the intersection of nature and national security. There are many biologists and ecologists who already think about how ecosystems provide goods and services to humanity. But these folks rarely extend the benefits of nature to entire nations. At the same time, there are individuals who work in positions that oversee national security and appreciate that global change can alter our security forecasts. However, they don’t often talk with biologists who understand which ecosystems and species are key service providers. Getting these two groups to talk and work together will go a long way towards advancing our understanding of how nature influences national security.   

Host of positive ‘tipping points’ can regenerate nature






University of Exeter





A host of positive “tipping points” can spark rapid nature recovery, a leading expert says.

Action to protect and restore nature must accelerate radically to meet global goals for 2030 and beyond.

Writing in the journal Nature Sustainability, Professor Tim Lenton says positive tipping points are key to achieving this.

He highlights potential tipping points – moments when a small change triggers a rapid, often irreversible transformation – in nature, human societies and areas where the two combine.

“The destruction and degradation of the natural world pose an existential threat,” said Professor Lenton, of the Global Systems Institute at the University of Exeter.  

“We are already crossing or approaching several dangerous ecological tipping points, including the dieback of warm-water coral reefs and the Amazon rainforest.

“But just as human activity can drive negative tipping, we can bring about positive tipping points to spark large-scale nature recovery.”

While addressing climate change is vital for protecting nature, specific social and ecological tipping points can regenerate ecosystems, spread nature-positive activities, and reduce drivers of nature loss.

Many governments are signed up to international goals to regenerate nature – such as protecting 30% by 2030 – but progress is going far too slowly. Crucially, triggering positive tipping points can help achieve the necessary acceleration in progress.

Positive tipping points offer opportunities for businesses who are trying to work out how they can have a positive impact on nature, and for finance companies who are trying to identify investable opportunities in nature regeneration.

Professor Lenton identifies four key types of positive tipping point for nature:

  • Ecosystem recovery: Numerous degraded ecosystems have been positively tipped into a regenerated state. For example, reintroduction of wolves in Yellowstone National Park in 1995-6 likely led to a positive tipping point of riverbank vegetation recovery, which in turn boosted the numbers of scavengers, songbirds, bison and beavers. In Pacific kelp forests, the removal of sea otters caused sea urchin populations to escalate and kelp to collapse. Sea otter recovery (or their reintroduction, for example in Alaska) tipped kelp forest recovery.
  • Social-ecological systems: Effective management of shared resources can lead to positive tipping points. For example, in pelagic (open sea) fisheries, positive tipping can be triggered by enforcing a Maximum Sustainable Yield – the highest yield that can be taken without significantly affecting reproduction. This typically requires short-term reduction in fishing, with strong enforcement. This has produced positive tipping points for recovery of plaice and hake stocks in the North Sea. In coastal fisheries, Marine Protected Areas (MPAs) can help positively tip fish stock recovery, by providing safe spawning areas and “spillover” of fish into the surrounding waters.
  • Nature-positive initiatives: The social spread of nature-positive initiatives can also become “self-propelling” – an important feature of a tipping point. For example, the small-group tree planting initiative (TIST) originated in Tanzania and spread rapidly in Kenya and Uganda – and to India – aided by a structure designed to maximise autonomy and social learning, and by providing multiple benefits to adopters, including carbon payments. In another example, success on Apo Island inspired the spread of marine reserves in the Philippines via the “reinforcing feedback” of social learning.
  • Consumption behaviour: Positive tipping points in patterns of consumption could reduce key drivers of nature loss. The most important driver of nature loss is agricultural expansion, primarily due to increased meat consumption. However, in several rich nations that overconsume meat, there have been significant recent reductions in meat consumption. Social norms and the quality, diversity and availability of meat-free options are key to enabling a positive tipping point. Professor Lenton also highlights strong “balancing feedbacks” that are opposing dietary change. For example, in the EU, four times as much farming subsidy goes into animal products as plant ones.

Professor Lenton said a key research opportunity is to test which current systems may be approaching a positive tipping point – potentially inspiring action to trigger it.

He identifies three levers that could enable multiple positive tipping points: facilitating online collective learning among groups taking nature-positive action, properly valuing nature in economics, and tipping worldviews to “ecocentrism”.

On the latter, Professor Lenton said: “Changing the ethical and legal status of nature is a powerful practical step to underpin nature-positive action. Such a tipping point in paradigm could be the deepest leverage point for nature-positive system change.”

The article is entitled: “Positive tipping points for nature.”

 

Firehorse superstition shows women’s education doesn’t affect family formation in Japan



Researchers leverage popular calendar superstition to understand the effects of women’s education on family formation and fertility rates




Waseda University

Investigating the causal effects of education on family formation rates in Japan 

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Researchers find novel causal evidence on the effect of Japanese women’s education level on family formation during periods of traditional gender norms. Using a unique quasi-experimental design in Japan, they find that increased educational opportunities lead to modest delays in marriage and motherhood without increasing the likelihood of lifelong singlehood.

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Credit: Associate Professor Rong Fu from Waseda University, Japan





The rapidly declining marriage and fertility rates across developed East Asian societies strain pension and healthcare systems, threaten economic growth, and reshape entire societies. To tackle this issue, governments in Japan and across East Asia have invested heavily in pronatalist measures, but often with limited success. For instance, Japan's government has repeatedly expanded childcare subsidies and parental leave provisions, yet the total fertility rate hit a record low of 1.20 in 2024. A common narrative in media commentary, policy circles, and even within families is that women are "too educated" or "too career-focused" to marry and have children. However, the exact causal relationship between women’s education level and family formation is not well understood.

To fill this knowledge gap, a team of researchers from Japan and Singapore, led by Associate Professor Rong Fu from the Faculty of Commerce, Waseda University, Japan, and Visiting Scholar at the Columbia Population Research Center, Columbia University, USA, used a novel quasi-experimental approach to understand the relationship between education, fertility, and marriage in Japan. Joining her in this collaboration were Assistant Professor Senhu Wang from the National University of Singapore, Singapore; Assistant Professor Yichen Shen from Kanagawa University of Human Services, Japan; and Professor Haruko Noguchi from Waseda University. Their findings were published online in the journal Demography on April 01, 2026.

For this study, the researchers leveraged the Japanese zodiac concept of the “Year of the Firehorse.” Women who are born during this particular zodiac year are believed to be particularly inauspicious for marriage, with the superstition suggesting that these women possess fierce temperaments that could lead to marital discord. Explaining the motivation behind their study Dr. Fu says, “As the Year of the Firehorse returns in 2026 for the first time in 60 years, our study uses the previous Firehorse year of 1966, which caused a dramatic baby bust driven by zodiac superstition, as a natural experiment to answer a question at the heart of East Asia's demographic crisis: Is women's education really to blame for declining marriage and fertility?”

In the Firehorse year of 1966, many prospective parents sought to avoid having children born under this supposedly inauspicious zodiac sign. This avoidance behavior resulted in a smaller cohort of women, born between January and March 1967, who faced reduced competition for educational resources in later years. Since the academic year in Japan begins in April, these individuals born in early 1967 were grouped with the previous year’s cohort for educational purposes. This mismatch was leveraged to identify a group of women born between January and March of 1967 who benefited from reduced school competition, yet were not subject to Firehorse-related discrimination.

The researchers report that women of the mismatch cohort, who gained greater access to education, delayed marriage by only about 2 weeks and first childbirth by about 40 days. These delays were temporary: by their mid-40s, more-educated women were just as likely to be married and to have children as their peers. Education shifted the timing of family planning and expansion, but it did not lead to women preventing or avoiding the same. In other words, education itself has only a minimal direct effect on whether and when women form families.

The present research suggests that such efforts may be targeting the wrong lever. If education is not the root cause of delayed family formation, then the focus should shift toward removing the structural barriers that educated women actually face: workplaces that penalize mothers, a persistent expectation that women bear the overwhelming share of childcare and housework, and a lack of flexible career re-entry paths after bearing a child or children.

Another finding in this work is that women are adapting economically but are still constrained by unchanged social structures. According to the authors, more educated women entered marriage with greater labor force participation, yet adhered to traditional marriage practices. Real-world progress in family formation likely requires institutional reforms that catch up with women's educational and economic advancement, such as genuine enforcement of paternity leave, flexible work arrangements that do not carry career penalties, and affordable, high-quality childcare to support women and empower them in building careers as well as families.

“The timing of our publication in a new Firehorse year also offers a real-world application of a different kind. If superstitious birth avoidance recurs in 2026, it would create another natural experiment, allowing researchers and policymakers to examine whether the same dynamics play out under today's very different gender norms and economic conditions,” concludes Dr. Fu.

 

***

 

Reference
Authors: 
Rong Fu1, Senhu Wang2, Yichen Shen3, and Haruko Noguchi4
DOI: 10.1215/00703370-12530548
Affiliations: 1Faculty of Commerce, Waseda University, Japan
2Department of Sociology and Anthropology, National University of Singapore, Singapore
3School of Health Innovation, Kanagawa University of Human Services, Japan
4Faculty of Political Science and Economics, Waseda University, Japan

 

About Waseda University
Located in the heart of Tokyo, Waseda University is a leading private research university that has long been dedicated to academic excellence, innovative research, and civic engagement at both the local and global levels since 1882. The University has produced many changemakers in its history, including eight prime ministers and many leaders in business, science and technology, literature, sports, and film. Waseda has strong collaborations with overseas research institutions and is committed to advancing cutting-edge research and developing leaders who can contribute to the resolution of complex, global social issues. The University has set a target of achieving a zero-carbon campus by 2032, in line with the Sustainable Development Goals (SDGs) adopted by the United Nations in 2015. 

To learn more about Waseda University, visit https://www.waseda.jp/top/en

 

About Associate Professor Rong Fu
Dr. Rong Fu is an Associate Professor at the Faculty of Commerce, Waseda University, Japan. Her research interests include economic policy and health economics. She specializes in health economics, demographic analysis, and policy evaluation. Her work involves employing quasi-experimental methods and large-scale administrative data to identify causal effects on health, education, and labor market outcomes across diverse populations and institutional contexts. She has authored 26 research papers on these topics, which have been cited 324 times. Dr. Fu is a member of Japanese Health Economics Association, American Economic Association, and Japanese Economic Association.

21ST CENTURY ALCHEMY

Redesigning metals at the atomic level to boost future technology



Discovery could help make electronics faster and more energy efficient



University of Minnesota

Tunable catalysi 

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Seung Gyo Jeong (left) and senior author Bharat Jalan (right) have created a new path toward tunable catalysis and electronics in this latest paper. 

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Credit: Kalie Pluchel, University of Minnesota-Twin Cities





MINNEAPOLIS / ST. PAUL (04/27/2026) — Researchers in the University of Minnesota Twin Cities have discovered a powerful new way to control the electronic behavior of a metal—by manipulating the atomic properties of materials where they meet.

The study, published in Nature Communications, demonstrates that interfacial polarization can tune the surface work function of metallic ruthenium dioxide (RuO2) by more than 1 electron volt (eV)—a tiny amount of energy—simply by adjusting film thickness at the nanometer scale.

“We often think of polarization as something that belongs to insulators or ferroelectrics—not metals,” said Bharat Jalan, professor and Shell Chair in the Department of Chemical Engineering and Materials Science at the University of Minnesota. “Our work shows that, through careful interface design, you can stabilize polarization in a metallic system and use it as a knob to tune electronic properties. This opens an entirely new way of thinking about controlling metals.”

This specific change is most powerful when the metal layer is about 4 nanometers thick—roughly the width of a single strand of DNA. At this precise size, the metal shifts from being "stretched" by the material underneath it to a more "relaxed" state. This transition proves that the physical way atoms are packed together has a direct, measurable impact on how the metal handles electricity.

“This was surprising,” said Seung Gyo Jeong, first author of the study and a researcher in Jalan’s group. “We expected subtle interface effects, but not such a large and controllable change in work function. Being able to visualize the polar displacements at the atomic scale and connect them directly to electronic measurements was especially exciting.”

Beyond fundamental physics, the findings could impact the design of next-generation electronic, catalytic and quantum devices. 

In addition to Jalan and Low, the research team included members from Department of Chemical Engineering and Materials Science at the University of Minnesota-Twin Cities, Massachusetts Institute of Technology, Texas A&M University, Gwangyu Institute of Science and Technology and the School of Physics at the University of Minnesota-Twin Cities.

The research was funded by the U.S. Department of Energy and the Air Force Office of Scientific Research. 

Learn more:

Read the full paper entitled, “Strain-Stabilized Interfacial Polarization Tunes Work Function Over 1 eV in RuO2/TiO2 Heterostructures,” on the Nature Communications website. 

 

An acoustic device helps reduce bycatch of endangered Black Sea porpoises




Pensoft Publishers
Bycaught porpoises 

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Bycaught Black Sea harbour porpoises.

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Credit: Dimitar Popov




The endangered Black Sea harbour porpoise (Phocoena phocoena relicta) is facing a critical fight for survival. As Europe’s smallest marine mammal, this isolated population is being pushed toward extinction by bycatch - the unintentional entanglement in fishing gear. The crisis is most acute in the Black Sea turbot fishery, where recent estimates reveal that more than 10,000 porpoises die annually.

Led by a strong motivation to address threats to this iconic species, a team of Bulgarian researchers has carried out a four-year trial study of 57 hauls seeking effective solutions to reduce porpoise mortality. The study, now published in Nature Conservation, found bycatch in 61% of all hauls, accounting for 189 cetaceans: 182 harbour porpoises, five bottlenose dolphins, and two common dolphins.

The trials did not begin promisingly, as the first two models of acoustic deterrent devices (pingers) tested proved ineffective at reducing bycatch.

- the researchers noted

This initial setback prompted the team to search for an alternative solution, eventually leading to a breakthrough with the PAL Wideband pinger, an acoustic deterrent device developed in Germany.

Field trials demonstrated that this device can reduce harbour porpoise bycatch in the Black Sea by approximately 74%. Researchers believe the specific acoustic signals, namely the wider frequency band (between 10 and 150 kHz) emitted by the PAL Wideband model, contributed to its effectiveness, as it was the only one of the three pingers tested, that successfully deterred porpoises from approaching fishing nets.

Other recent studies have highlighted significant shortcomings in the conservation of harbour porpoise populations in European waters,” the researchers stated. This underscores the urgent need for effective strategies to reduce bycatch, the leading human-induced cause of mortality for the species.

Mitigation measures could include spatio-temporal closures of high-risk fisheries in areas where harbour porpoises are most abundant, as well as the adoption of alternative or modified fishing gear, including the use of acoustic deterrent devices.

-  the experts emphasized

Among the available options, the use of effective pingers, supported by appropriate financing mechanisms, is increasingly seen as one of the most practical and widely accepted approaches to reducing bycatch while maintaining profitable fishing operations.

Not all acoustic deterrent devices are equally effective in reducing the bycatch of the harbour porpoise in the Black Sea.

- they concluded

Their findings demonstrate that certain pinger models fail to mitigate porpoise bycatch in the bottom-set gillnets specifically used to target turbot.

The study underscores the importance of careful selection and testing of deterrent devices and emphasizes that this distinction must be explicitly taken into account in the development of targeted and effective strategies to reduce bycatch in Black Sea fisheries.

 This study is part of the topical collection “Black Sea ecosystem in the spotlight”.

Original source:

Popov D, Meshkova G, Dimitrov H, Panayotova M (2026) Can pingers mitigate the bycatch of the endangered Black Sea Harbour Porpoise? Nature Conservation 63: 1-15. https://doi.org/10.3897/natureconservation.63.183768

 

Scrapped inheritance tax linked to stronger growth in private firms with heirs, Swedish study shows



Stockholm School of Economics




After Sweden removed inheritance and gift taxes in 2005, private firms with potential family successors grew faster, invested more, and paid higher corporate taxes than firms without natural heirs, according to a new white paper from the Stockholm School of Economics. The study adds empirical evidence in a policy debate often dominated by ideology and comes as several European countries debate inheritance tax reforms.

Using population data covering about 37,000 companies, the research shows that firms led by owners with children – indicating a possible path to family succession – grew sales, profits, and assets more than similar firms led by childless owners. Profitability improvements also led to greater increases in corporate tax payments, suggesting a potential shift, rather than reduction, in public revenue over time.

The study compared the firms’ financial performance between 2001 and 2007, three years before and after Sweden’s inheritance tax was repealed.

“Before the reform, owners often had to plan for future tax payments tied to inheritance,” says co-author Mattias Nordqvist, professor at the House of Innovation, Stockholm School of Economics. “That may have limited how much capital they reinvested. After the tax was removed, the firms retained more earnings and invested more in growth.”

A natural experiment in tax policy

Debates around inheritance and gift taxes often fall along ideological lines, with arguments focused on the need to curb wealth inequality versus concerns about punitive taxation schemes that may trigger investment flight.

While many European countries levy inheritance taxes, Sweden abolished its own in 2005 after decades of debate. Before that, rates were progressive, typically ranging from about 10-30 percent for close relatives and reaching as high as 50-60 percent for more distant heirs.

The reform created a natural experiment by allowing researchers to compare firms led by owners with children against childless owners whose strategic decisions were less likely to be shaped by inheritance tax considerations.

To ensure comparability, the researchers matched firms by owner age and then applied a difference-in-differences approach, tracking changes in firm outcomes before and after the reform.

Following the tax abolition, sales at firms with potential successors were up by 8 percentage points more in 2007 compared with heirless firms. These firms had also increased total assets at a 4-percentage point higher rate and grown equity by up to 7 percentage points more, relative to the pre-abolition baseline year of 2003.

They also improved the operating margin by nearly half a percentage point more in the first two years before the difference levelled out in 2007. Corporate tax payments also rose more, with a difference of 10 percentage points over three years, and employee salaries grew at a 12-percentage point higher rate in 2007 relative to the control group.

Overall, these findings suggest that rents from the tax abolition were not simply appropriated by the owner-managers but instead shared with society through taxes and employee salaries.

A shift from one-time to recurring tax revenues

“The loss in inheritance tax revenue for the state may thus have been offset in the long term by higher future recurring taxes tied to business activity,” says co-author Mateja Andric, assistant professor at the University of Melbourne and affiliated researcher at the House of Innovation, Stockholm School of Economics. “When those constraints were lifted, the firms appeared more willing to invest, grow and strengthen their operations over time, which in turn benefited society through the higher taxes and employee salaries these companies paid.”

The findings contribute to a limited but growing body of research on how inheritance taxation shapes firm behaviour. While debates often center on wealth distribution or large family conglomerates, the study highlights effects among smaller, founder-led and owner-managed firms that may become family businesses in the future.

“In many European economies, the majority of firms are privately held and relatively small,” says co-author Mohamed Genedy, postdoctoral researcher at the House of Innovation, Stockholm School of Economics. “Understanding how tax policy affects their long-term decisions is essential for assessing broader economic consequences, including investment, employment and tax revenues.”

At the same time, the authors stress that the results should be interpreted with care. The paper focuses on one country and one reform, and outcomes may differ depending on institutional context and policy design.

White paper: “The Impact of Abolishing the Gift and Inheritance Tax on Firm Strategic Decisions and Outcomes: The Case of Sweden,” Mateja Andric, Mohamed Genedy and Mattias Nordqvist, online April 15, 2026, doi: 10.2139/ssrn.6528658