The research, led by Anna K. Berryman of the University of Oxford together with Fernanda Senra de Moura of the University of Oxford and the World Bank, and R. Maria del Rio-Chanona of University College London, builds on earlier work showing that productivity-led structural transformation towards less land-intensive sectors, such as manufacturing, can substantially reduce deforestation. That earlier analysis, by J. B. de Souza Ferreira Filho and Marek Hanusch, used a dynamic computable general equilibrium (CGE) model with spatially explicit land-use transitions to show that productivity gains in urban, traded sectors weaken agriculture’s relative competitiveness and lower the economic incentive to clear forest land. What the CGE framework could not reveal, however, is what such a transformation would mean for the millions of Brazilian workers whose livelihoods depend on the sectors being reshaped.

To close that gap, the team developed a spatially and occupationally explicit agent-based labour market model, informed by empirically observed job-transition networks, to simulate how workers respond to labour demand shocks. The empirical backbone of the model is Brazil’s Relação Anual de Informações Sociais (RAIS) dataset, which records all active employer–employee contracts in the country’s formal labour market. From 2011 to 2019 data, the researchers constructed a regional occupational mobility network in which each node represents an occupation–region pair and each weighted edge reflects the historical probability of workers moving between pairs. The network comprises 410 occupations across 16 regions of Brazil.

The network analysis revealed two powerful frictions that constrain how workers can adapt to structural change. Workers were 62% more likely to transition into an occupation within the same broad category than into a different one, and 7.2 times more likely to remain within their home state than to relocate. Quantifying these patterns with assortativity measures, the team found that regional assortativity in the regional occupational network reached 0.77, while occupational assortativity at the one-digit level stood at 0.56. Strikingly, when the regional occupational mobility network was visualized, its structure closely resembled the geographical map of Brazil itself, underscoring how strongly geography, moving costs and familial ties shape labour flows.

The agent-based model itself runs in monthly time steps and tracks employed workers, unemployed workers and unfilled vacancies for every occupation–region pair. Each month, workers may lose jobs through routine turnover or through state-dependent separations driven by mismatches between realized and target labour demand, while vacancies open through analogous spontaneous and state-dependent processes. Unemployed workers search for new positions by applying to vacancies in occupations and regions connected to their previous job through the empirical mobility network, and the matching process uses an urn-ball matching function in which one applicant is drawn at random whenever at least one worker applies. The researchers calibrated the model’s three key parameters using quarterly unemployment and nominal GDP data from 2012 to 2019, achieving unemployment rate correlations exceeding 0.93, and validated it on out-of-sample data from 2020 to 2025, where it successfully reproduced the sharp unemployment spike caused by the COVID-19 pandemic.

The team then coupled this labour market model to the CGE scenarios developed by Ferreira Filho and Hanusch, which simulate how Brazil’s economy and environment might evolve from 2018 to 2030 if productivity grew by 0.5 percentage points annually in manufacturing, agriculture, services or mining. Because the CGE model outputs labour demand at the industry level, the researchers converted it to occupation-level demand using the observed occupational composition within each industry. The coupling is one-directional: labour demand projections inform the labour market model, but labour market outcomes do not feed back into the macro-economic projections. Even though aggregate labour demand in each scenario equals the baseline by design, layoffs and vacancies emerge at the disaggregated occupation–region level, and it is precisely there that the frictions bite.

The results are sobering. Across nearly all productivity-driven scenarios, high-wage and high-skill workers experienced unemployment rates below the baseline, while lower-wage workers, particularly in agriculture, faced increased unemployment. Agricultural workers, who are among the least spatially and occupationally mobile, were negatively affected in almost every scenario, with unemployment rate increases ranging from 0.13 to 2.11 percentage points. The scenario delivering the best environmental outcomes, a nationwide shift towards more productive manufacturing powered by Brazil’s low-carbon energy supply, improved employment prospects for mid- and high-skill workers but raised unemployment for agricultural and other low-skill workers. The only scenario in which agricultural workers fared better than baseline was one where agricultural productivity in the Amazon increased disproportionately, yet in that scenario deforestation and emissions rose significantly, making it the worst environmental performer.

At the fine-grained four-digit occupation level, the model revealed how a worker’s position in the mobility network determines their fate. In São Paulo, garment sewing machine operators and hand weavers, handmade shoe and leather goods craftsmen faced similar demand decreases but divergent unemployment effects: the former suffered increased unemployment because their neighbouring occupations were also declining, while the latter remained nearly unaffected because their neighbours were thriving. Similarly, among agricultural workers in the southern model region comprising Santa Catarina and Rio Grande do Sul, general agricultural and agricultural support workers faced unemployment increases about 0.95 percentage points higher than farm supervisors despite nearly identical demand changes of roughly minus 9%. On the vacancy side, firms struggled to fill positions for middle-level technicians and professionals of sciences and arts. Civil and allied engineers in Roraima, facing 7% higher demand, saw vacancy rates rise by about 0.50 percentage points, whereas CNC machinists in the same state, facing even larger demand growth of 8.8%, saw vacancies remain nearly unchanged because workers from declining neighbouring occupations could flow into those jobs. Spatial frictions compounded the problem in remote northern states such as Acre, Amapá, Rondônia and Roraima, where firms could not fill positions even as unemployment rose elsewhere in the same occupations.

The most hopeful finding concerns policy. When the researchers reran the scenarios with an intervention that increases agricultural workers’ mobility into occupations with similar skill levels in other sectors, such as mid-level, industrial and repair-and-maintenance occupations, unemployment outcomes for Amazon agricultural workers improved by approximately 50% on average under the manufacturing growth scenario, with scenario-led unemployment increases between 0.02 and 0.11 percentage points lower in regions including Acre, Amapá, Amazonas, Matopiba, Pará, Rondônia and Roraima. This demonstrates that well-designed labour market policies, including retraining, reskilling and relocation support, can align productivity gains with equitable employment outcomes.

The study’s implications reach far beyond Brazil. The authors note that their findings echo evidence from the United States showing that a green transition may not dramatically shift employment geographically but requires different skills. Because the analysis relies on formal labour market data covering roughly 67% of the total labour force, informal workers in services, agriculture and industrial-craft occupations remain under-represented, a limitation the researchers say future work should address using sources such as the Brazil National Household Sample Survey. Still, the central message is clear: deforestation is not merely a problem of forest governance and enforcement, but a reflection of deeper structural patterns in the macro-economy. Skills development policies must be implemented early, the authors argue, so that the green transition can be both fast and fair, ensuring that the workers least equipped to move are not left behind as Brazil steers its economy away from the forest frontier.

Subject of Research: Labour market skill and spatial mismatches shaping deforestation-reducing development pathways in Brazil

Article Title: Skill and spatial mismatches for sustainable development in Brazil

Article References: Berryman, A. K., de Moura, F. S., Bücker, J., Barbrook-Johnson, P., Hanusch, M., Mealy, P., Farmer, J. D., & del Rio-Chanona, R. M. (2026). Skill and spatial mismatches for sustainable development in Brazil. Nature Sustainability. https://doi.org/10.1038/s41893-026-01939-z

Image Credits: AI Generated

DOI: 10.1038/s41893-026-01939-z

Keywords: Brazil, Amazon, deforestation, labour market, agent-based modelling, skill mismatch, spatial mobility, structural transformation, green transition, unemployment, Nature Sustainability, economic complexity

The team’s central insight is that climate mitigation does not simply reduce global harm; it revalues national assets. Four categories dominate this revaluation. Fossil fuel production, a privately owned revenue engine for petrostates, loses value as demand for coal, oil and gas declines. Avoided climate damages, a public good, grow in value for countries exposed to heat, drought and storm damage. Renewable energy potential—sunlight and wind—acquires new economic worth as solar panels and turbines substitute for combustion. And land carbon sequestration capacity, the ability of forests and soils to absorb carbon dioxide, becomes a monetizable asset through carbon markets and offset programs such as REDD+. Each asset shapes national interests in distinct ways, and the study treats them separately rather than collapsing them into a single index.

To construct this atlas, the researchers integrated an unusually broad set of models and data streams. They drew on the Intergovernmental Panel on Climate Change’s Sixth Assessment Report scenario database, climate projections from six models in the Coupled Model Intercomparison Project Phase 6, land-use projections from three integrated assessment models—REMIND-MAgPIE, GCAM-Demeter and IMAGE—and the MAgPIE-LPJmL framework for land carbon stocks. Economic damages were estimated with six distinct damage functions, spanning growth-based approaches such as Burke-Hsiang-Miguel and Dell-Jones-Olken, and level-based approaches including Kalkuhl-Wenz, Tol and Hope. All values were discounted at 3 percent and expressed as shares of each country’s cumulative discounted GDP, allowing a small economy’s stakes to be compared with those of a giant.

The analysis spans three scenarios built on the middle-of-the-road Shared Socioeconomic Pathway 2: a stringent mitigation pathway (SSP2-2.6), a moderate pathway (SSP2-4.5) and a high-emissions baseline (SSP2-6.0). Two time horizons—mid-century and end-century—capture how asset values evolve. This design isolates the effect of mitigation ambition itself, holding socioeconomic assumptions constant, so that differences between scenarios reflect climate policy rather than divergent development paths.

The results on fossil fuel rents are stark. Under stringent mitigation relative to the baseline, Iran, Venezuela, Canada and Norway face the largest losses in discounted fossil fuel revenues when coal, oil and gas are combined. These losses, expressed as a share of cumulative GDP, translate directly into political resistance: countries with heavy fossil fuel dependence have both the motive and, in some cases, the institutional means to obstruct ambitious climate commitments. The study finds empirical support for this link through cross-country regressions relating the four asset categories to six climate policy indicators, with fossil fuel rent losses correlating with weaker climate policy ambition.

On the other side of the ledger, avoided damages concentrate in lower-income, climate-vulnerable countries. By end-century under stringent mitigation, many African countries see particularly large gains, led by the Democratic Republic of the Congo, where avoided damages reach 3.3 percent of cumulative discounted GDP. Renewable energy potential tells a parallel story of concentration: Somalia exhibits the largest renewable mitigation potential in the dataset, at 108.2 percent of cumulative GDP, from combined photovoltaic, onshore and offshore wind resources. Land carbon sequestration capacity clusters in tropical forest nations—Guyana, Suriname, Papua New Guinea and several Central African countries—while only ten countries remain net carbon sources by 2100 under stringent mitigation, compared with twenty under moderate mitigation.

To move from individual countries to geopolitical structure, the team applied k-means clustering across the four aggregate indicators, sorting the 169 countries into five groups: fossil-fuel-dependent economies, avoided-damage economies, high-carbon-sequestration economies, high-potential renewable economies and moderate-impact economies. Hierarchical clustering assigned 146 of 169 countries—86.4 percent—to the same groups, and most disagreements fell near cluster boundaries, suggesting the typology is robust. The fossil-fuel-dependent cluster contains just 19 countries but includes many members of the Organization of the Petroleum Exporting Countries, whose strategy of opposing fossil fuel phase-out commitments exemplifies the interests the data reveal. Crucially, this cluster holds only 6.0 percent of global GDP, limiting its ability to block a broad coalition.

The most politically charged finding concerns the moderate-impact cluster, which contains 69 countries and 81 percent of global GDP—including the United States, the European Union and China. These major powers experience comparatively moderate changes across all four asset categories, meaning their asset-based stakes in ambitious mitigation are weaker than their economic weight would suggest. Meanwhile, the avoided-damage cluster, with 51 countries and strong interests in climate action, holds only 10.7 percent of global GDP, and the sequestration and renewable clusters together account for a mere 2.4 percent. The persistent deadlock in global climate negotiations may partly reflect this misalignment: the countries with the largest potential gains lack the bargaining power to secure them, while the countries with the power to act have comparatively muted asset-based incentives.

Beyond clustering, a pairwise similarity analysis using eight detailed sub-indicators—coal, oil and gas rent losses separately, avoided damages, solar and wind potential, and natural versus managed sequestration—identifies each country’s closest counterparts. Some pairings track existing relationships: the United States and Mexico share moderate avoided damages and small fossil fuel losses, reinforced by integrated trade networks. Others are strikingly counterintuitive: China’s closest counterpart is Bosnia and Herzegovina, and India’s is Bulgaria—profiles marked by limited mitigation assets, modest avoided damages and coal rent exposure. Saudi Arabia’s nearest match is Iraq, both defined by oil dependence, while Brazil aligns with Peru through substantial avoided damages and moderate sequestration capacity. These similarities do not imply broader socioeconomic resemblance, but they suggest that countries with very different development levels may face comparable configurations of climate assets—and therefore comparable negotiating positions.

The authors are careful about limits. Their framework excludes overseas fossil fuel interests, relies on median values from heterogeneous model ensembles, and omits extreme events such as heatwaves and droughts in its land carbon estimates. National interests, they note, are shaped by ethics, governance, institutional capacity and historical responsibility that no asset ledger can capture. Yet the dataset, publicly available through Zenodo, offers negotiators and researchers a starting point for designing package deals—linking research cooperation, trade agreements or financial transfers to mitigation commitments—that could align the interests of powerful but moderately affected states with those of vulnerable, resource-rich nations. As the low-carbon transition accelerates, the study suggests that the decisive question is no longer whether climate action reshapes global power, but whether the countries gaining most can convert their new assets into the influence needed to unlock it.

Subject of Research: Country-level quantification of climate mitigation assets and their geopolitical implications

Article Title: Quantifying assets for the geopolitics of climate change mitigation

Article References: Pan, G., Kornek, U., Gong, C. C., Molina Bacca, E. J., Luderer, G., & Edenhofer, O. (2026). Quantifying assets for the geopolitics of climate change mitigation. Nature Sustainability. https://doi.org/10.1038/s41893-026-01971-z

Image Credits: AI Generated

DOI: 10.1038/s41893-026-01971-z

Keywords: climate change mitigation, geopolitics, fossil fuel rents, renewable energy, carbon sequestration, avoided damages, integrated assessment models, Nature Sustainability, climate policy, international cooperation, SSP scenarios, economic damage functions

The research team, led by PIK researcher Guanna Pan, constructed a dataset that tracks four distinct channels through which climate policy affects a country’s economic position. First, ambitious mitigation reduces global demand for oil, gas and coal, potentially stripping fossil fuel exporters of future revenue streams. Second, cutting emissions limits the climate-related damage that heating would otherwise inflict on national economies, from agricultural losses to infrastructure destruction. Third, the transition opens new economic opportunities in solar and wind energy development, rewarding countries with abundant renewable resources. Fourth, climate policy raises the value of a nation’s capacity to absorb and store carbon dioxide from the atmosphere, whether through natural sinks such as forests or through managed stewardship of natural areas. By combining these four ledgers, the researchers could estimate, country by country, how gains and losses from decarbonisation could unfold by the end of this century, depending on the level of ambition in climate policy.

The headline numbers are striking. Countries that are highly vulnerable to the phase-out of oil, gas and coal account for just 6 percent of global economic output. At the other end of the ledger, the study identifies groups of countries that would benefit disproportionately from rapid climate action, including those in Africa whose vast solar energy potential positions them as natural winners of the renewable energy transition. Perhaps most surprising, the economic interests of the United States, Europe and China, often portrayed as divergent in climate negotiations, are affected by climate policy in remarkably similar ways.

To make sense of this complex landscape, the research team clustered the 169 countries into five groups whose members share similar economic opportunities and risks under climate policy, and therefore potentially shared geopolitical interests. The smallest and most exposed cluster comprises 19 fossil fuel-dependent countries that would potentially oppose ambitious mitigation measures, since decarbonisation directly devalues their core national assets. By contrast, 51 countries in the Global South have a strong interest in a rapid climate transition, because without one they would face particularly severe climate damages to their economies. A third cluster of 13 countries with high potential for renewable energy, the majority of them in Africa, would naturally favour swift action, as would a fourth cluster of 17 countries with high carbon sequestration capacity, whose forests and natural areas gain value as the world prices in carbon removal.

Yet the arithmetic of political weight tells a more complicated story. The three clusters of countries that especially stand to benefit from climate protection account for only 13 percent of global economic output combined, while the fossil fuel-dependent group represents just 6 percent. The remaining 81 percent of global economic output belongs to the fifth and largest cluster: 69 economies with moderate impacts, a group that includes the European Union, China and the United States. For these countries, the absolute economic benefits of climate policy are considerable in many cases, particularly because of avoided climate damage to their large economies. Calculated as a percentage of national output, however, their relative gains are not as large as in the three clusters of strong winners. This distinction between absolute and relative benefit matters for the politics of climate negotiation, since it shapes how urgently each bloc perceives its own stake in the outcome.

According to Pan, the analysis allows researchers to map how countries could gain or lose from different aspects of decarbonisation by the end of this century, depending on how ambitious climate policy turns out to be. The team explored the geopolitical tensions that may arise when some countries anticipate losses, but the study also shows how national interests can foster international cooperation, and how such cooperation can be further strengthened through targeted incentives. In other words, the same dataset that reveals potential fault lines also points to the bargaining space where deals can be struck.

The study’s central recommendation is that where interests diverge, climate cooperation should be strengthened through package deals. Concessions on climate protection for hesitant countries could be linked with promises regarding trade or research and development, or losses could simply be offset through financial transfers. This approach reflects a long-standing insight from negotiation theory: when parties value different assets unevenly, structured exchanges can leave everyone better off than a standoff. The clustering framework gives negotiators a concrete starting point for identifying which countries might be brought to the table by which combinations of trade access, technology cooperation or compensation.

The findings arrive at a moment when opposition to committed climate policy is resurgent in several major economies. Ottmar Edenhofer, Director of PIK and a co-author of the study, argues that the debate has been framed too narrowly. In his view, it is important to recognise that climate policy does not merely devalue certain assets, namely those of fossil fuel suppliers. The study demonstrates, he says, quite precisely how new assets are simultaneously being built up. Overall, climate policy revalues the capital stock of economies in a new and sustainable way, thereby safeguarding long-term prosperity. This reframing shifts the question from whether climate policy destroys wealth to how it redistributes and creates it across borders and decades.

For humanity as a whole, the research team notes, there is a collective interest in climate action, since avoided damages accrue globally. But the study insists that the differences in gains and losses between countries need to be fully understood rather than glossed over. The five-cluster map provides the necessary guidance, showing that the politics of decarbonisation are not a simple binary of winners and losers but a mosaic of overlapping and sometimes conflicting asset positions. The 19 fossil fuel-dependent states may resist, but they carry little collective economic weight; the strong winners of the Global South, Africa’s solar powers and the carbon sequestration countries may push for speed, but they too represent a minority of output. The decisive middle, the 69 moderate-impact economies holding 81 percent of global output, holds the balance, and its members’ considerable absolute benefits from avoided climate damage suggest that enlightened self-interest, reinforced by well-designed package deals, could carry the transition.

As a piece of quantitative geopolitics, the study marks a step change in how the economic stakes of climate mitigation can be visualised and negotiated. By quantifying national assets across fossil revenues, avoided damages, renewable opportunities and carbon storage capacity for 169 countries, it turns abstract debates about ambition into concrete maps of interest. Whether those maps become the blueprint for cooperation or merely a sharper picture of division will depend on whether the international system can convert shared data into shared deals before the century’s warming trajectory is locked in.

Subject of Research: New world map reveals which countries win and lose most from climate policy

Article Title: A world map of climate policy: Who stands to gain most?

Article References: A world map of climate policy: Who stands to gain most?. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: climate policy, geopolitics, decarbonisation, Potsdam Institute, Nature Sustainability, fossil fuels, renewable energy, carbon sequestration, package deals, Global South, world, climate

The technical achievement behind these numbers lies in the data fusion the researchers assembled. To identify where wetlands had been converted to crops, the team drew on GLC_FCS30D, a global land-cover dynamics product at 30-meter resolution built from dense time series of Landsat imagery, alongside GlobeLand30 and fine-resolution wetland maps that distinguish marshes, swamps, floodplains, and coastal and tidal wetlands. Crop productivity was estimated using satellite-derived net primary production from the GLASS dataset, cross-checked against CROPGRIDS, a geo-referenced global dataset covering 173 crops, and crop-calendar information from the GGCMI Phase 3 archive. Flood hazard came from three independent sources: the European Commission’s Joint Research Centre global flood hazard map for a 100-year return period, a global coastal flood map, and the satellite-based Global Flood Database, which records actual inundation events observed from orbit. By layering these datasets in Google Earth Engine and validating the results at case-study sites, the researchers produced the first globally consistent picture of what happens when wetlands become fields.

The productivity findings strike at the heart of the rationale for reclamation. The team compared yields on wetland-reclaimed croplands with those on existing croplands and with the yields achievable on other agricultural land, quantifying a local yield gap for each converted parcel. Nearly half of the reclaimed croplands showed lower yields than established farmland, and the penalty was especially severe where upland crops such as maize, wheat or soybeans were planted on soils that had spent millennia functioning as saturated wetland ecosystems. Waterlogged, often saline or organic-rich wetland soils are poorly suited to the root systems and drainage requirements of upland cereals, and the legacy hydrology of a drained wetland can suppress productivity for years after conversion. The aggregate result is stark: despite occupying real land area, wetland-reclaimed croplands contributed only about 0.1 percent of total global crop production between 2000 and 2022, a contribution so small that it barely registers in the global food ledger.

Against that marginal gain, the flood exposure numbers are alarming. More than half of the world’s wetland-reclaimed croplands face severe flood hazards, and their average flood exposure probability is 23 times higher than that of all croplands globally. This is not a coincidence of geography but a structural feature of the conversion itself. Wetlands occupy low-lying positions in the landscape, in river floodplains, lake margins, deltas and coastal zones, precisely the places where water accumulates during heavy rainfall, snowmelt, storm surges and high tides. Intact wetlands act as natural sponges and buffers, storing floodwater and releasing it slowly, a regulating service documented extensively in the hydrological literature. When the wetland is drained and planted, the land loses that buffering capacity while remaining in the flood’s path. The result is a double exposure: the crops are grown where floods naturally occur, and the removal of the wetland makes the surrounding landscape more flood-prone as well.

The study’s most consequential finding is what the researchers call dual vulnerability. Globally, 60 percent of wetland-reclaimed croplands suffer simultaneously from limited agricultural gains and high flood exposure, meaning they produce less food than conventional farmland while facing dramatically greater odds of inundation. Using a multi-objective trade-off analysis, the team identified hotspots where both problems converge, and those hotspots are not randomly distributed. They cluster disproportionately in food-importing countries and in low-income countries, places where the capacity to absorb crop losses is weakest and where dependence on domestic harvests is often highest. In such settings, a single flood event can wipe out harvests on fields that were already underperforming, compounding food insecurity rather than relieving it. The pattern inverts the usual logic of agricultural expansion, which assumes that bringing new land under cultivation adds resilience to the food system.

The historical context makes the new findings more urgent rather than less. Previous research, including a landmark 2023 analysis in Nature, estimated that extensive global wetland loss over the past three centuries has been driven substantially by agricultural conversion, and meta-analyses of wetland conversion drivers have consistently ranked crop cultivation among the leading causes worldwide. Climate change is now amplifying the stakes. Studies of global flood risk under warming scenarios project that extreme precipitation and rising sea levels will intensify flood hazards in exactly the low-lying coastal and deltaic regions where wetland reclamation has been most aggressive. Meanwhile, satellite observations have shown that the proportion of the global population exposed to floods has been increasing, and rapid development in flood zones continues worldwide. Draining wetlands in the twenty-first century therefore means farming land whose flood risk is rising, not static, and doing so at the cost of the very ecosystems that moderate that risk.

The environmental costs extend well beyond flood regulation. Converting wetlands to cropland is known from global meta-analyses to increase greenhouse gas emissions, particularly when coastal wetlands, riparian zones and peatlands are drained, because the carbon accumulated in waterlogged soils oxidizes rapidly once exposed to air. Wetland conversion also alters soil microbial communities along entire soil profiles and disrupts the water-use balance between wetlands and surrounding agriculture, creating conflicts that have been documented from closed watersheds to large river basins. Biodiversity losses follow, which is why the researchers overlaid their maps with Ramsar sites, wetlands of international importance under the global conservation convention, and Important Bird Areas. The new study adds an economic dimension to this already long list of costs: if the land produces little food and frequently floods, then the carbon emissions, habitat destruction and hydrological disruption are being incurred for almost no agricultural return.

What makes the analysis particularly valuable for policymakers is its explicit treatment of trade-offs. Rather than presenting a single average, the team used a Pareto-based framework, drawing on multi-objective optimization methods, to map where agricultural gains and flood risks trade off against each other across regions and countries. The distribution of trade-off hotspots among regions with different food-production and consumption profiles revealed that the burden of bad conversions falls unevenly. Countries that import food, and countries with lower incomes, host a disproportionate share of the doubly vulnerable croplands, suggesting that wetland reclamation often occurs not where it makes agronomic sense but where land pressure and economic constraints push expansion onto marginal, flood-prone terrain. This echoes a broader finding in the sustainability literature that win-win outcomes are rare in complex environmental management, and that land-use decisions made under scarcity tend to externalize risks onto the most vulnerable.

The policy implications are direct. The authors argue that wetland reclamation should be recognized as an unsustainable agricultural expansion strategy and that food security and wetland conservation must be reconciled rather than treated as competing goals. Practical alternatives exist. Restoration of farmed wetlands can enhance flood resistance, as demonstrated by research on returning farmlands to lakes, which measurably improved agricultural flood protection in affected regions. Improving yields on existing cropland, reducing food waste, shifting diets and improving trade systems can all relieve the pressure that drives expansion onto wetlands in the first place. International frameworks, including the Ramsar Convention and national wetland protection policies, provide legal instruments, but the new evidence suggests they need to be integrated with agricultural planning so that subsidies and land-use permits stop incentivizing conversion of the world’s remaining wetlands.

For a planet that must feed nearly ten billion people by mid-century while halting catastrophic biodiversity loss, the study delivers a clear quantitative verdict: the world’s wetlands are a poor place to look for extra food and a dangerous place to farm. The full datasets and analysis code have been released publicly through Zenodo, allowing other researchers to scrutinize the findings and apply the framework to national and regional planning. As floods intensify under a warming climate, the fields carved out of the world’s marshes and deltas over the past two decades stand as a global natural experiment with an unambiguous result. The water, in the end, comes back, and it comes back to land that was never well suited to grow crops in the first place.

Subject of Research: Global assessment of crop productivity and flood exposure on wetlands converted to agriculture from 2000 to 2022

Article Title: Limited agricultural gains but high flood risk from global wetland reclamation

Article References: Zhang, X., Dong, J., Shang, Y., Chen, X., Wang, X., Singha, M., Peng, S., Fluet-Chouinard, E., Tellman, B., & Xiao, X. (2026). Limited agricultural gains but high flood risk from global wetland reclamation. Nature Sustainability. https://doi.org/10.1038/s41893-026-01965-x

Image Credits: AI Generated

DOI: 10.1038/s41893-026-01965-x

Keywords: wetlands, agriculture, flood risk, food security, land use change, cropland expansion, remote sensing, Nature Sustainability, ecosystem services, wetland conservation, sustainability, floodplain farming

The concept at the heart of the study is known as leakage, the displacement of land-use pressures from areas under intervention to areas outside them. Negative leakage occurs when restoration replaces productive farmland or timber plantations, or when it reduces landowner earnings, prompting people to compensate by clearing trees elsewhere. Positive leakage is the opposite: when restored landscapes supply fuelwood, fodder and other resources, or generate employment and financial incentives, pressure on surrounding natural forests can actually decline. Until now, most evidence on restoration effectiveness has focused narrowly on outcomes inside project boundaries, leaving these off-site dynamics largely unmeasured, even though they can fundamentally alter whether a project delivers net climate and biodiversity benefits.

To close that gap, the researchers assembled a geospatial database of restoration activities across sub-Saharan Africa by combining four sources, including the TIST Restoration Program, the World Bank’s Sustainable Land Management Program in Ethiopia, the Restor platform, and boundaries of nature-based carbon offset projects. The final dataset contained 129,982 polygons established between 1996 and 2023, spanning 27 countries, which the team grouped into 19,229 clusters based on geographic proximity. Natural regeneration, whether passive or assisted, accounted for the largest share at 56.1 percent of the restored area, with a marked surge of roughly 3.9 million hectares after 2015. Intensively managed active restoration covered 40.2 percent, growing steadily at about 0.2 million hectares per year, while agroforestry contributed just 3.8 percent. Kenya, Ethiopia and Cameroon together held over 85 percent of the total restored area.

The analytical design was rigorous. The team generated buffer zones of 5 and 10 kilometers around each restoration cluster and tracked annual tree cover loss using the Hansen Global Forest Change dataset within project areas and their surroundings, comparing them against carefully constructed counterfactuals. They employed two complementary control approaches: one using areas earmarked for restoration but not yet treated, and another using statistically matched never-restored plots with comparable biophysical and socio-economic conditions, including slope, elevation, population density, travel time to markets, distance to roads, baseline tree cover and agricultural suitability. A heterogeneity-robust difference-in-differences model, the estimator developed by Callaway and Sant’Anna, then isolated the causal effect of restoration on tree loss dynamics over time, a method chosen because conventional two-way fixed effects models can produce biased estimates when treatment timing is staggered and effects vary across groups.

The results for natural regeneration were unambiguously encouraging. Ten years after restoration began, tree loss within restored areas had fallen by up to 6.8 percentage points relative to yet-to-be-treated controls, and by 2.3 percentage points against matched controls. More remarkably, the benefits spilled outward: tree loss dropped by 6.5 to 8.7 percentage points in the 5-kilometer buffers and by up to 9.1 percentage points in the 10-kilometer buffers, depending on the counterfactual used. Active restoration showed a similar pattern, with reductions of roughly 3 to 5 percentage points within project areas and up to 6 percentage points in surrounding buffers over ten years. These findings suggest that well-implemented restoration of native woody ecosystems can generate landscape-scale gains that current project-level accounting systematically overlooks.

Agroforestry told a very different story. Beginning around five to six years after establishment, tree loss increased both within agroforestry projects and in the surrounding landscape, a signature of negative leakage. After ten years, tree loss had risen by 7.9 percentage points within project areas and 7.5 percentage points in the 10-kilometer buffers under the yet-to-be-treated comparison. The likely mechanisms are biophysical and economic. As trees mature, shading and root competition can reduce crop yields on what remains actively farmed land, prompting farmers to clear nearby forest or fallow land to compensate. Commercially oriented systems such as cocoa, coffee and rubber can also inflate land values and shift labor toward clearing for short-term gain, particularly where land tenure is unclear or compensation inadequate. This contrasts sharply with Southeast Asia, where agroforestry has been shown to reduce deforestation, likely because it is embedded in long-standing community forestry systems with stronger tenure arrangements.

The timing of these effects differed revealingly among approaches. Natural and assisted regeneration tended to reduce deforestation within one to two years, probably because protection measures such as fencing and fire management take effect immediately and community engagement builds early momentum. Agroforestry’s negative leakage emerged only after about six years, when trees grew large enough to compete with crops. This delay matters for policy: short-term monitoring windows, typical of many funding cycles, would miss the problem entirely. The authors also caution that most sites in their dataset are young, averaging 6.7 years since implementation, so long-term ecological performance remains uncertain and extrapolation to longer timescales should be treated carefully.

Country-level analysis revealed enormous heterogeneity, with leakage estimates ranging from minus 7.8 to plus 7.1 percentage points. Kenya and Tanzania showed consistent positive leakage across all restoration approaches, with active restoration in Tanzania reducing tree loss by as much as 11.6 percentage points at the 5-kilometer scale. Rwanda, Cameroon, Madagascar and Nigeria also showed positive leakage under active restoration. On the other side, Ethiopia saw tree loss rise by 5.6 percentage points within actively restored areas, Ghana showed negative leakage in its 10-kilometer buffers under both natural regeneration and active restoration, and South Africa recorded a striking 52.4 percentage point increase in tree loss within actively restored sites. In Uganda and the Democratic Republic of Congo, outcomes split by approach, with active restoration delivering gains while agroforestry increased tree loss. The contrast between struggling collective agroforestry schemes in the DRC, where poverty pushed farmers to prioritize their own plots, and Kenya’s successful Vi Agroforestry program, which improved household incomes and fuelwood access, illustrates how tenure security, incentive structures and participation modes can determine whether leakage reinforces or undermines local resilience.

The implications reach directly into carbon markets and restoration finance. Because certification standards typically quantify benefits only within project boundaries, they risk underestimating the true value of natural regeneration and active restoration, whose spillover benefits extend to surrounding high-conservation-value habitats, while simultaneously overestimating the net climate value of agroforestry projects that displace tree loss outward. The authors argue that leakage safeguards must be integrated into restoration planning, carbon standards and incentive schemes, alongside landscape-scale land-use zoning, cross-sector coordination between agriculture and forestry, secure land tenure and long-term monitoring funded over decadal timescales. With agroforestry covering 60 million hectares under AFR100 commitments and supporting 1.2 billion people worldwide, getting these safeguards right is not an academic nicety but a prerequisite for restoration that genuinely delivers on its climate and biodiversity promises.

Subject of Research: Leakage effects of forest restoration approaches on tree cover loss in sub-Saharan Africa

Article Title: Restoration-driven positive and negative leakage in sub-Saharan Africa

Article References: Miao, X., Morton, O., Bousfield, C. G., Werden, L. K., Thomas, S. M., Crowther, T. W., Ryan, C. M., & Edwards, D. P. (2026). Restoration-driven positive and negative leakage in sub-Saharan Africa. Nature Sustainability. https://doi.org/10.1038/s41893-026-01936-2

Image Credits: AI Generated

DOI: 10.1038/s41893-026-01936-2

Keywords: forest restoration, leakage, sub-Saharan Africa, natural regeneration, agroforestry, tree cover loss, carbon markets, AFR100, difference-in-differences, land tenure, Nature Sustainability, biodiversity

The core of the innovation is a photon–phonon co-driven strategy, abbreviated PPCC by the team. Conventional photocatalysis uses light alone to drive chemical reactions, while thermocatalysis relies purely on heat. Each approach has inherent limits. Photocatalysis suffers from a quantum efficiency ceiling, because a single photon can only do so much work, and thermocatalysis often forces a trade-off between yield and selectivity. Methanol conversion to hydrogen and formaldehyde is particularly demanding: it is an endothermic process that doubles the gas-phase volume, and it proceeds through two sequential dehydrogenation steps, each with a different activation energy. No single energy input can efficiently satisfy both. By coupling 365-nanometre ultraviolet light from an LED with moderate heating at 150 degrees Celsius in a continuous-flow reactor, the Tsinghua team matched each elementary step with the energy source best suited to it, photons for the hardest activation step and phonons, the lattice vibrations that carry thermal energy, for the rest.

The catalyst itself is a masterclass in atomic-scale engineering. Platinum single atoms were anchored to a mixed anatase-rutile titanium dioxide support and surrounded by lithium, forming what the evidence suggests are PtLi2 clusters. The optimal formulation, containing roughly 0.3 weight percent platinum and 0.2 weight percent nominal lithium input, delivered a hydrogen production rate of 4.36 moles per gram of catalyst per hour at 150 degrees Celsius, a figure 30.3 times higher than unmodified TiO2 and roughly an order of magnitude above the best low-temperature thermal catalytic benchmarks. The apparent turnover frequency reached a record 275,000 per hour. Even more striking is the overall quantum yield of 184 percent, a value exceeding 100 percent because thermal energy contributes additional driving force beyond the incident photons alone. In the dark, the same catalyst at the same temperature managed only 0.11 moles per gram per hour, confirming that light is the primary driver and heat the essential promoter.

Crucially, the carbon does not end up as carbon dioxide. Instead, the dominant carbon-containing product is formaldehyde, produced with 94 percent selectivity at a synthesis rate of 3.5 moles per gram per hour. In batch experiments, the team accumulated a concentrated formaldehyde solution of 21.2 weight percent after just 140 minutes, a strength approaching commercial grades used in medicine and in the manufacture of industrial resins and plastics. Formaldehyde is currently made by oxidizing methanol over silver catalysts at around 600 degrees Celsius or iron-based catalysts at around 350 degrees, a process that consumes more than 30 percent of global methanol output. Co-generating hydrogen and formaldehyde from a single mild-temperature process therefore offers two saleable products with net-zero carbon emissions and complete atomic utilization of the methanol feedstock.

Lithium turned out to be the quiet hero of the story, performing no fewer than five distinct jobs. First, it retards the recombination of photogenerated charge carriers in the catalyst bulk, extending the lifetime of the reactive electrons and holes. Second, it facilitates electron transfer from the TiO2 bulk to the platinum reaction sites, with density functional theory calculations showing that the intrinsic electron transfer energy becomes more favourable as lithium is added, and that lithium lowers the quantum tunnelling barrier for directional electron injection. Third, it weakens the binding of hydrogen atoms on the platinum surface; computed adsorption free energies shift from a strongly binding minus 0.32 electronvolts on platinum nanoparticles to a nearly ideal minus 0.04 electronvolts on the Pt1Li2 site, easing hydrogen desorption and avoiding catalyst poisoning. Fourth, it maximizes the fraction of platinum present as Pt2+ rather than metallic Pt0, which the team’s poisoning experiments identified as the true active sites. Fifth, and perhaps most importantly, it stabilizes those single atoms against aggregation.

That stabilizing role was demonstrated with unusual rigour. X-ray photoelectron spectroscopy showed that in a lithium-free Pt–TiO2 catalyst the Pt2+ fraction collapsed from 70 percent to 29 percent within one hour of reaction, while in the lithium-modified material it barely moved, from 100 percent to 96 percent. Extended X-ray absorption fine structure revealed growing platinum-platinum coordination in the unmodified catalyst, a signature of clustering, but no such change in the lithium version. Identical-location electron microscopy, in which the very same catalyst particles were imaged before and after one hour under realistic reaction conditions, directly visualized new platinum nanoparticles forming and existing particles growing on Pt–TiO2, while the lithium-stabilized sample remained atomically dispersed. The practical consequence was dramatic: the catalyst ran stably for 19 days under a simulated solar cycle of eight hours illumination and sixteen hours darkness, maintaining hydrogen output and formaldehyde selectivity above 94 percent throughout.

The mechanistic picture that emerges from transient absorption spectroscopy, isotope labelling, in situ electron paramagnetic resonance and infrared measurements is an elegant division of labour between light and heat. Photons excite charge carriers in TiO2, which couple to the lattice to form polarons; thermal phonons then help these polarons hop to the surface rather than remaining trapped. On the surface, water adsorbs more strongly than methanol, so photogenerated holes preferentially oxidize water to hydroxyl radicals. These radicals, rather than the holes themselves, attack methanol, abstracting a hydrogen atom to form the hydroxymethyl radical, a step calculated to cost only 0.37 electronvolts compared with roughly 0.83 electronvolts for direct hole-driven cleavage. Kinetic isotope experiments confirmed that carbon-hydrogen bond cleavage in methanol is the rate-determining step, and it is precisely this demanding step that the energetic photogenerated carriers are positioned to drive. The subsequent dehydrogenation of the hydroxymethyl intermediate to formaldehyde, by contrast, is a nearly barrierless thermal transformation that phonons alone can push forward.

The team also showed the concept scales in a practical sense: connecting two flow reactors in series boosted hydrogen production by 1.7 times, and the system tolerated variations in light intensity, pressure, flow rate and catalyst loading that were systematically optimized. The 40 percent methanol feed concentration proved optimal, with control experiments showing that any carbon dioxide formed arises secondarily from formaldehyde reforming with water rather than from direct over-oxidation. Isotope labelling with deuterated methanol confirmed that hydrogen atoms from the methyl group of methanol end up in the hydrogen gas, while hydroxyl hydrogens exchange with water, consistent with the proposed cascade.

Beyond the headline numbers, the significance of this work lies in its conceptual generality. Photon–phonon co-driven catalysis offers a framework for any transformation hobbled by an activity-selectivity trade-off, by assigning each elementary step to the energy input that matches its activation barrier. The authors argue that future progress will depend on reactor engineering tailored to dual energy fields, explicitly managing photon transport and heat flow to balance the energy budget. If those engineering challenges can be met, a methanol economy in which the liquid fuel doubles as a hydrogen battery and a chemical feedstock, releasing no carbon dioxide in the process, moves a decisive step closer to industrial reality.

Subject of Research: Photon–phonon co-driven catalytic conversion of methanol to hydrogen and formaldehyde using lithium-modified platinum single atoms on titanium dioxide

Article Title: Green synthesis of hydrogen and formaldehyde from methanol with enhanced quantum efficiency

Article References: Zhao, J., Xiong, L., Zheng, Y., Nie, Q., Yu, Z., Guo, J., Li, X., Liu, Q., Sun, X., Zheng, X., Wang, Z., Selloni, A., Gong, X., Huang, W., & Tang, J. (2026). Green synthesis of hydrogen and formaldehyde from methanol with enhanced quantum efficiency. Nature Sustainability. https://doi.org/10.1038/s41893-026-01959-9

Image Credits: AI Generated

DOI: 10.1038/s41893-026-01959-9

Keywords: hydrogen production, methanol, formaldehyde, single-atom catalysis, photocatalysis, photon–phonon co-driven catalysis, platinum catalyst, titanium dioxide, lithium modification, quantum yield, green chemistry, Nature Sustainability

The study is notable for the breadth of its evidence. Rather than relying on a single dataset, the team combined three waves of individual-level surveys with more than 2,300 to 3,000 respondents each, official municipality-level registration records for solar PV systems and electric vehicles, and federal and state election results covering 10,733 German municipalities. The survey waves, conducted in December 2022, May 2024 and August 2024, captured both actual adoption and stated intentions, while the administrative data allowed the researchers to track real deployment from 2000 to 2023 for solar and 2014 to 2023 for electric vehicles. This dual approach matters because self-reported preferences can diverge from observed behaviour, and the fact that both point in the same direction strengthens the overall picture.

The partisan gap is striking, and it differs sharply between technologies. Averaged across survey waves, supporters of the pro-environmental Green party were 48 percent more likely than AfD supporters to report adopting or intending to adopt solar panels, but a staggering 227 percent more likely when it came to electric vehicles. In regression models controlling for income, education, age, household composition and state-level characteristics, AfD supporters were 67 percent less likely to report electric vehicle adoption outcomes than supporters of other parties, a difference that grew stronger among politically engaged respondents. For solar, the equivalent gap was smaller and not statistically significant, hinting that the more mature and economically established technology has become somewhat less politically charged.

Underlying beliefs appear to drive much of this divide. When asked about the climate benefits of swapping a combustion engine for an electric vehicle, only 26 percent of AfD supporters agreed, compared with 61 percent of Green supporters. Just 9 percent of AfD supporters viewed the raw materials needed for electric vehicle production as abundant, versus 31 percent of Green supporters. Perceptions of residential solar were more favourable across all political groups, and partisan differences were correspondingly narrower. This pattern fits a social identity framework in which highly visible, symbolically loaded technologies like electric cars become markers of political affiliation, while technologies perceived as ordinary household investments attract less ideological resistance.

The municipality-level data mirror these individual-level patterns. In 2023, solar PV penetration was 44 percent higher in municipalities leaning toward the Greens than in those leaning toward the AfD, while more than 4 percent of registered vehicles were electric in Green-leaning municipalities compared with roughly 2 percent in AfD-leaning ones. The absolute gap between municipalities in the top and bottom quintiles of the AfD–Green vote-share difference widened in every observed year. Yet in relative terms the gap actually narrowed: solar penetration was initially about 76 percent lower in AfD-leaning municipalities but only 31 percent lower by 2023, and the electric vehicle gap fell from 84 percent in 2015 to 60 percent in 2019. As technologies mature and adoption rates rise everywhere, even shrinking relative differences translate into ever larger absolute shortfalls.

Correlation alone cannot settle the question, because political ideology is entangled with income, education, rurality, housing stock and countless other factors that also shape technology adoption. To address this, the researchers deployed two complementary strategies. The first was a panel regression relating within-municipality changes in AfD vote share to subsequent changes in technology penetration, with municipality fixed effects absorbing time-invariant local differences and county-year fixed effects capturing local policy and economic shocks. These models found that a one-percentage-point increase in AfD vote share was associated with reductions of 0.02 percentage points in solar penetration and 0.03 percentage points in electric vehicle penetration, both highly significant.

The second strategy is the study’s most eye-catching feature: an instrumental-variable analysis that uses wolf attacks on livestock as a source of quasi-random variation in far-right support. Previous research by Clemm von Hohenberg and Hager documented that wolf attacks, which have surged as the animals returned to Germany from Eastern Europe, predict increases in AfD vote share, particularly in rural areas where the party has amplified concerns about safety and rural livelihoods. In this study, wolf attacks strongly predicted AfD support, with effective F-statistics well above conventional thresholds, and a doubly robust difference-in-differences estimate suggested attacks raised AfD vote share by about 1.3 percentage points. A placebo test using the Green vote share produced near-zero effects, suggesting the instrument captures shifts in far-right support rather than broad political realignment.

Using this instrument, the researchers found that municipalities whose voting behaviour was shifted by wolf attacks showed reductions of 0.76 percentage points in solar penetration and 0.18 percentage points in electric vehicle penetration associated with higher AfD support. These estimates are larger than the panel results, which the authors attribute to the local nature of the effect: the instrument identifies impacts only for municipalities, disproportionately rural and agricultural, where wolf attacks moved votes, and the attacks may have made broader far-right positions, including climate scepticism, more politically salient. The authors are careful to note that the instrument’s estimates are not robust to splitting the sample into eastern and western Germany and should be read as complementary evidence rather than definitive causal proof.

Counterfactual simulations translate these associations into concrete terms. The panel models imply that had AfD vote shares remained at their 2013 baseline, solar PV diffusion by 2023 could have been up to 1.3 percent higher nationwide, and electric vehicle diffusion up to 2.9 percent higher. Among wolf-affected municipalities, the instrument-based estimates imply 4.1 to 6.2 percent more solar installations and 2.3 to 5.8 percent more electric vehicles. The researchers stress these are illustrative calculations rather than precise causal counts, but they demonstrate that the political dynamics are large enough to matter for national climate goals, particularly given that households account for over 60 percent of global greenhouse gas emissions through their consumption.

The findings carry implications well beyond Germany. Most existing evidence on ideology and clean technology comes from the United States, where partisan battles over solar panels and electric cars are well documented; this study shows similar dynamics operating in a proportional democracy with a different party system and a much longer history of mainstream climate policy. It also highlights that polarization is not static: the association between far-right support and adoption may have strengthened over time, and the study period predates any substantial far-right governing power, leaving open how adoption might respond if the AfD directly shaped policy. For policymakers, the message is that subsidies alone may not close the gap. As the authors note, durable diffusion increasingly hinges on preferences, cultural acceptance and trust, meaning that the politics of the energy transition may now be as important as its economics.

Subject of Research: The relationship between far-right political support and the adoption of residential solar photovoltaics and electric vehicles in Germany

Article Title: Far-right political support and clean technology adoption in Germany

Article References: Reining, S., Wussow, M., Zanocco, C., Kau, B., Sousa-Silva, R., Köpke, C., Pathiraja, S., & Neumann, D. (2026). Far-right political support and clean technology adoption in Germany. Nature Sustainability. https://doi.org/10.1038/s41893-026-01935-3

Image Credits: AI Generated

DOI: 10.1038/s41893-026-01935-3

Keywords: far-right politics, AfD, solar photovoltaics, electric vehicles, clean technology adoption, political polarization, Germany, energy transition, instrumental variables, wolf attacks, climate policy, Nature Sustainability

The research team, led by Rudi Voss of Kiel University and the German Centre for Integrative Biodiversity Research, together with colleagues from institutions in Germany, the United States, Denmark and Italy, faced a formidable data problem. Direct records of medieval catches are sparse, scattered across toll books, customs registers and royal pre-emption accounts known as kongekøb. To fill the gaps, the team combined these fragments with indirect indicators, most importantly the availability and price of salt from the Lüneburg saline, the essential production factor for preserving herring. Demographic trends and general economic conditions served only as consistency checks rather than quantitative inputs, a deliberate design choice that prevents circular reasoning when those same social variables are later tested as drivers of the system. The result is not a precise year-by-year dataset but a smoothed trend curve that captures the major dynamics of the fishery with confidence that varies across centuries.

The reconstructed time series divides naturally into four phases that eerily mirror the trajectory of modern fishery collapses, including the famous Atlantic northwest cod fishery. During the expansion phase from 1200 to 1315, catches in the Sound alone reached a first maximum of roughly 23,000 tonnes around the year 1300, driven by rising demand and the growing availability of high-quality Lüneburg salt. A long stagnation followed from 1315 to 1520, as cooling temperatures depressed agriculture, famines struck between 1315 and 1322, and the Bubonic plague killed an estimated 25 to 35 percent of Europe’s population around 1350, decimating the fishing workforce. Deflation caused by a shortage of gold and silver drained money from the economy, and a series of Baltic wars disrupted trade. Output nevertheless held steady at 19,000 to 23,000 tonnes.

Then came the boom. As the crisis of the Late Middle Ages receded, populations recovered, precious metals flowed back into the economy and the herring market expanded. After Danish wars had initially blocked its growth, the fishery flourished under King Frederic I from 1523 onward. Average output of the Scanian fishery soared to about 55,000 tonnes between 1524 and 1570, with some years exceeding 75,000 tonnes. Contemporaries noticed the strain: the average weight of an individual herring had fallen from about 154 grams in the Viking Age to 82 grams around 1400, and dropped temporarily to 67 grams in 1485, meaning fish were being caught three to four years younger. Pelagic trawl nets were banned as early as 1371, and mesh-size regulations followed in 1386, suggesting that medieval society recognized overfishing long before the word existed.

To test whether this pressure actually destroyed the stock, the team applied a recently developed bioeconomic stock assessment method, or BESA, which exploits the interplay between catch and price data in an unregulated, open-access fishery. Under open access, fishers enter and exit until profits are driven to zero, so price fluctuations reveal how effort responded to changing incentives. The method, built on a state-space model with an extended Kalman filter and Bayesian estimation, allowed the researchers to estimate maximum sustainable yield, stock biomass relative to carrying capacity and the influence of temperature on the stock’s natural growth rate. Four decadal price series from herring markets in England, Hamburg, Brabant and Utrecht provided independent estimates of the same underlying stock.

The verdict was nuanced and surprising. During the boom phase, catches clearly exceeded sustainable limits, and the stock shrank to between 41 and 51 percent of its maximum observed biomass. Yet there was no biological collapse. The herring population declined but remained viable, a conclusion independently supported by ancient DNA and genomic analyses showing that population dynamics over the period were consistent with environmental change rather than pure overexploitation. After the fishery’s breakdown, catches fell far below estimated sustainable levels, eventually averaging perhaps 1,000 tonnes per year in the seventeenth and eighteenth centuries, inferred from tax records of fishers in Kronborg Len. Medieval yields were not matched again until the 1950s.

If the fish did not disappear, why did the fishery? To answer this, the team turned to loop analysis, a qualitative modelling technique that represents the socioecological system as a signed, directed network of nine variables spanning ecology, economy and society, including herring stock, harvest, workforce, demand, population size, economy, agriculture, climate cooling and war. Loop analysis requires only the signs of interactions, not their precise strengths, making it ideal for data-poor historical systems. By applying sustained press perturbations, such as a shift toward cooling, and tracing effects through all direct and indirect pathways, the method predicts the direction of change for every variable. The researchers validated the model against the catch time series across the four historical phases.

The predictions reproduced the observed dynamics with striking fidelity: likely harvest increases during expansion, a slight decline during stagnation, a strong rise during the boom and an unambiguous, severe decrease signaling collapse after 1570. Crucially, climate cooling alone could not explain the outcome. Colder conditions directly reduced herring productivity, since autumn-spawning herring are sensitive to harsh winters, but indirect effects, such as cooling’s damage to agriculture and the resulting demographic decline, transmitted mixed signals through the network. The collapse emerged only from the interplay of local factors like the workforce, regional factors like the economy and demand, and large-scale forces like climate and war. After the 1570s, shifting dunes buried the fair towns of Skanor and Falsterbo, herring shoals fluctuated unpredictably, fishermen emigrated to the booming Bohuslän fishery on Sweden’s west coast, cheap and larger North Sea herring captured demand, and enforced serfdom barred peasants from leaving their landlords’ fields to fish in autumn.

The study also reveals a subtle economic mechanism: because harvesting costs in the BESA framework are stock-dependent, a smaller herring stock raised the cost of every tonne caught. Meanwhile, North Sea fisheries, with a season three times longer and seaworthy boats that outperformed Baltic vessels by a factor of twenty, were flooding the market. The Baltic fishery likely became economically uncompetitive before the fish were ever gone, a divergence between economic viability and ecological sustainability that bioeconomic theory predicts but historical data rarely document so clearly. For centuries, pressures had partly offset one another, keeping catches moderate; in the early sixteenth century they aligned to boost the fishery, and by mid-century they reversed to destroy it.

The lessons reach directly into the present. The western Baltic spring-spawning herring stock, though a different population from the medieval autumn spawners, is now outside safe biological limits and subject to zero-catch advice, its decline driven by overfishing and compounded by climate-driven recruitment failure and food-web interactions. The authors argue that recovery remains possible if fishing mortality ceases, but that management must also address socioeconomic pressures, as now discussed in high-level political groups in Denmark and Germany and reflected in the recent report of the German Commission on the Future of Baltic Sea Fisheries, which recommends improving infrastructure and diversifying coastal economies. History’s message is stark: a fishery is a coupled human-natural system, and no amount of biological stock assessment alone can prevent its collapse. Understanding the people, prices, wars and weather that surround the fish is not a luxury of interdisciplinary scholarship but a requirement for keeping the sea’s silver flowing.

Subject of Research: Socioeconomic and environmental drivers of the medieval western Baltic herring fishery collapse

Article Title: An historic fishery collapse driven by socioeconomic and environmental factors

Article References: Voss, R., Schmidt, J. O., Lehmann, O., Okamoto, D., Polte, P., Lancker, K., Grunwald, A., & Scotti, M. (2026). An historic fishery collapse driven by socioeconomic and environmental factors. Nature Sustainability. https://doi.org/10.1038/s41893-026-01937-1

Image Credits: AI Generated

DOI: 10.1038/s41893-026-01937-1

Keywords: Baltic Sea, herring fishery, fishery collapse, overfishing, climate change, Little Ice Age, loop analysis, bioeconomic stock assessment, socioecological systems, medieval trade, fisheries management, Nature Sustainability

The central insight of the new work is that the three most desirable properties of an air filter need not live in the same solid material. Conventional fibrous filters, including the melt-blown polypropylene media used in respirators and the dense glass-fibre mats inside HEPA units, capture particles mechanically or electrostatically on solid surfaces. Every captured particle stays put, gradually blocking the pores, raising the pressure drop across the filter and eventually forcing a costly replacement. The CILF instead delegates capture to a dynamic liquid lining that is continuously replenished, so that trapped contaminants are swept away rather than accumulated.

The researchers organise the capture process into three stages that operate in sequence. In the first stage, long-range electrostatic attraction draws airborne particles toward the filter from a distance, exploiting electric charges to overcome the fundamental weakness of purely mechanical filtration, in which only particles that happen to collide with a fibre are removed. In the second stage, particles arriving at the liquid interface are captured rapidly at the surface, where capillary and electrostatic forces combine to pull them across the boundary between air and liquid. In the third stage, the liquid bulk itself acts as a high-capacity sink, absorbing and storing the collected particles deep within its volume.

This division of labour is what gives the filter its durability. Because the liquid lining is refillable and continuously renewed, particles that would otherwise clog a solid filter are instead dissolved or suspended in the liquid phase and carried off. The team reports that the filter maintained high performance throughout 3,500 hours of continuous operation, a figure that dwarfs the service intervals typical of high-efficiency solid filters, which often degrade noticeably within weeks of intensive use. The self-cleaning behaviour of the moving liquid lining means the filter does not progressively blind itself, and the pressure drop across it remains stable rather than climbing over time.

The design builds on a growing body of work on liquid-based filtration. In 2022, a team reported in Nature a continuous air purification approach based on aqueous interface filtration and absorption, demonstrating that liquids could serve as active capture media rather than passive wetting agents. Related efforts have explored liquid-gating mechanisms with tunable multiphase selectivity and antifouling behaviour, first described in Nature in 2015, as well as biomimetic systems inspired by the human circulatory and respiratory systems. The new contribution of the CILF is to combine the liquid approach with charge-induced capture, adding the long-range electrostatic attraction that pure liquid-interface systems lack while retaining their resistance to clogging.

The physics of the interfacial capture stage draws on well-studied phenomena. Particles sitting at liquid interfaces experience capillary forces that can bind them strongly to the boundary, and electric fields can induce attractive interactions between like-charged particles at such interfaces, an effect documented experimentally more than two decades ago. By engineering the charge state of the liquid lining, the researchers harness these forces deliberately: particles approaching the interface are pulled in and then drawn into the bulk liquid, where the vast absorption capacity of the liquid phase stores them far from the airstream. Supplementary videos accompanying the paper show charge-induced adsorption on solid surfaces, bulk-phase absorption in the liquid, and the dynamic liquid lining performing its self-cleaning function.

To demonstrate that the laboratory performance translates into practical air cleaning, the team built a full-scale air cleaner prototype incorporating the CILF. In a thirty-cubic-metre test chamber, the prototype achieved a clean-air delivery rate of 377 cubic metres per hour, a measure of how much purified air a device can supply and one of the key metrics used to compare commercial air purifiers. The tests were conducted under industry standard conditions, providing a benchmark that allows direct comparison with existing filtration technologies rather than relying solely on laboratory-scale measurements.

Perhaps the most striking aspect of the work is the breadth of applications the researchers demonstrate. The team implemented the filters across a range of real-world settings, from personal protective masks to air purification systems compatible with microgravity environments. The microgravity application is particularly notable: conventional filters rely on gravity-assisted settling and replaceable cartridges that generate waste, both of which are problematic on spacecraft, where every kilogram of consumables must be launched at great expense. A filter whose capture medium is a refillable liquid, and whose performance does not depend on gravity, offers an intriguing option for long-duration missions. At the other end of the scale, a liquid-lined filter in a face mask could in principle maintain high efficiency without the breathing resistance that builds up as solid mask filters load with particles.

The energy and sustainability implications are significant. Because the filter maintains a low and stable pressure drop, the fans driving air through it consume less power than they would against a progressively clogging medium, and the refillable liquid lining replaces the steady stream of discarded filter cartridges that conventional high-efficiency systems generate. Prior analyses of air filtration have highlighted both the monetary cost of replacing high-efficiency filters and the environmental burden of disposing of them, and low-cost do-it-yourself air cleaners popularised during the COVID-19 pandemic underscored the demand for affordable, durable alternatives. A filter that combines HEPA-level efficiency with long service life and simple maintenance addresses precisely the gap that has kept such alternatives from matching professional equipment.

Challenges remain before charge-induced liquid-lined filters appear in homes, hospitals and spacecraft. The nature and management of the working liquid, its consumption rate, the electrical power needed to sustain the charge-induced capture, and the behaviour of the system across extremes of temperature and humidity are all questions that the broader deployment of the technology will need to answer, and the paper’s supplementary materials, including extensive notes and tables, suggest the authors have begun mapping this terrain in detail. Still, the headline numbers are difficult to ignore: 99.6 percent single-pass efficiency at a face velocity of one metre per second, 3,500 hours of continuous high performance, and a clean-air delivery rate of 377 cubic metres per hour in a full-scale prototype. If the approach scales as the authors suggest, the familiar ritual of replacing clogged filters may one day give way to simply topping up a liquid reservoir, and the trade-off that has defined air purification for decades may finally be resolved in favour of clean air that is simultaneously efficient, durable and affordable.

Subject of Research: A charge-induced liquid-lined filter for high-efficiency, durable and low-maintenance air purification

Article Title: Highly efficient air purification by a charge-induced liquid-lined filter

Article References: Zhang, J., Li, M., Chen, S., Guo, Z., Yang, B., Li, L., Zhou, X., Zhang, J., Ye, C., Liu, J., Yao, W., Zhang, Y., & Hou, X. (2026). Highly efficient air purification by a charge-induced liquid-lined filter. Nature Sustainability. https://doi.org/10.1038/s41893-026-01920-w

Image Credits: AI Generated

DOI: 10.1038/s41893-026-01920-w

Keywords: air purification, liquid-lined filter, electrostatic capture, particulate matter, Nature Sustainability, filter durability, clean-air delivery rate, interfacial science, self-cleaning, microgravity, sustainable technology, fluidics

Marine heatwaves are defined as extended periods during which ocean temperatures remain far above the seasonal norm. As the climate warms, these events are becoming more frequent, longer-lasting and more intense, a trend that climate models project will accelerate through the middle of the century. The ecological consequences are well documented: mass coral bleaching, seagrass die-offs, shifts in species distributions and collapses of locally important fisheries have all been recorded after major marine heatwave events. What has been missing, the authors argue, is a systematic accounting of what these environmental disruptions mean for people, particularly the coastal communities whose food, income and cultural identity are bound to the sea.

The study lays out several pathways through which ocean warming translates into human harm. The first is extreme weather. Higher ocean temperatures pump additional energy and moisture into the atmosphere, contributing to more intense storms and flooding. The health consequences of such events are immediate and severe, ranging from injury and death during the events themselves to displacement, loss of shelter and the long-term disruption of health services in affected regions. By intensifying these hazards, marine heatwaves extend the reach of ocean warming well beyond the coastline and into the domain of disaster preparedness and emergency medicine.

A second pathway runs through the food supply. Marine heatwaves can trigger blooms of harmful algae, some of which produce toxins that accumulate in shellfish and finfish. When contaminated seafood reaches markets, it can cause outbreaks of poisoning that public health authorities may struggle to trace back to an oceanic origin. At the same time, heat-driven damage to fisheries and aquaculture operations can sharply reduce seafood availability. This is not merely an economic problem. For communities that depend heavily on marine resources for protein and micronutrients, a decline in seafood supply translates directly into risks for food security and nutrition, with children and other vulnerable groups most exposed.

The third pathway is psychological. Professor Bayden Russell, Associate Professor of Ecology and Biodiversity at HKU and senior author of the paper, emphasised that for many people the ocean is far more than a place for recreation. It provides food, income, cultural identity and a sense of place. When marine heatwaves damage coral reefs, fisheries and other marine resources, the communities that depend on them can experience grief, anxiety and uncertainty about the future. Russell noted that these mental health impacts are likely to be substantial, yet they remain largely unrecognised and understudied in both the climate science literature and public health practice.

The geographic distribution of this risk is deeply uneven, and Asia sits at its centre. Hundreds of millions of people across the region depend on the ocean for food, livelihoods and cultural practices, from small-scale fishing households in Southeast Asia to coastal megacities that draw a substantial share of their animal protein from the sea. The same region is also projected to experience some of the fastest increases in marine heatwave days over the coming decades. The combination of high exposure, high dependence and rapid warming makes ocean-dependent Asian communities a priority case for the kind of integrated planning the researchers are calling for.

The core policy argument of the paper is that marine heatwaves deserve the same institutional treatment as heatwaves on land. Over the past two decades, many governments have developed heat-health action plans that link meteorological forecasts to hospital preparedness, public warnings and outreach to vulnerable populations. No comparable framework exists for the ocean. The researchers propose incorporating marine heatwave forecasts into public health planning, considering health impacts explicitly in marine and coastal management decisions, and building stronger collaboration between ocean scientists, health authorities and natural resource managers. In their view, the technical ingredients for such a system already exist; what is lacking is the institutional connection between them.

Dr Laura Falkenberg of Adelaide University framed the challenge in blunt terms, saying that recognising these health impacts is the first step towards better protecting communities. She added that as marine heatwaves become increasingly common, the scientific and policy community needs to move from simply documenting impacts after they occur to preparing communities in advance, and that better planning today can reduce future health risks. This shift from retrospective damage assessment to anticipatory risk management mirrors the transformation that land-based heatwave science underwent after the deadly European heatwave of 2003, which forced public health systems to treat extreme heat as a forecastable, preventable hazard rather than an unavoidable natural event.

The technical foundations for anticipatory management are advancing rapidly. Oceanographers can now detect the atmospheric and oceanic conditions that precede marine heatwaves, and seasonal forecast systems are improving in their ability to flag regions at risk weeks to months in advance. Fisheries managers can use such outlooks to adjust catch limits, aquaculture operators can time harvesting and relocate stock, and health agencies can pre-position monitoring for harmful algal blooms and seafood contamination. Russell observed that the devastating effects of marine heatwaves on marine ecosystems have been recognised for some time, but that what has been missing from the conversation is what these events mean for people, adding that scientists are only just beginning to understand how these environmental impacts can produce large negative effects on human health.

The study’s publication in Nature Sustainability signals a deliberate attempt to move the issue out of marine ecology and into the interdisciplinary mainstream of sustainability and health research. Its authors hope that framing marine heatwaves as a public health threat will unlock new sources of funding, new institutional partners and new policy levers, from health ministry early-warning systems to coastal development rules that account for the psychological value of intact marine ecosystems. As ocean temperatures continue to climb and heatwave days accumulate through mid-century, the researchers argue that the cost of inaction will be measured not only in bleached corals and collapsed fisheries, but in injuries, poisoned seafood, lost livelihoods and the quiet burden of anxiety and grief carried by communities watching the sea they depend on change faster than they can adapt.

Subject of Research: Human health impacts of marine heatwaves

Article Title: HKU ecologists warn that marine heatwaves pose an underestimated threat to public health

Article References: HKU ecologists warn that marine heatwaves pose an underestimated threat to public health. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: marine heatwaves, public health, ocean warming, food security, harmful algal blooms, mental health, fisheries, aquaculture, coastal communities, climate change, Nature Sustainability, early warning systems