Source: The Conversation – Canada – By Sarah Foster, Program Leader, Project Seahorse and Senior Researcher, Institute for the Oceans and Fisheries, University of British Columbia
Bottom trawlers extract one-quarter of the world’s fisheries catches by weight and raise significant ecological, economic and social concerns. Given that, you’d think there would be an answer to basic questions in fisheries: how many fish species are being caught, and what are they?
In reality, though, bottom trawling is often proceeding blindly.
Bottom trawling is widespread and problematic. Gears operate by dragging large weighted nets across the ocean floor (some as wide as a 45-storey building is tall), sweeping up most of the life they encounter along the way and destroying habitat.
By far the biggest threat to seahorses is their incidental capture in bottom trawls. (Unsplash/Giulia Salvaterra)
We lead a conservation team called Project Seahorse, dedicated to ensuring there are more fish in the ocean in healthier ecosystems. We focus our work on securing healthy populations of seahorses — and to save seahorses, we have to save the seas.
By far the biggest threat to seahorses is their incidental capture in bottom trawls. As such, seahorses provide an index of the tremendous intensity of bottom trawling.
It was while developing a briefing on bottom trawl impacts that we realized no one knew the actual tally or diversity of fish getting caught up in nets. So we set out to provide an answer and in so doing unveiled more about the pressure bottom trawling is placing on marine species, ecosystems and fisheries worldwide.
Endangered species
Our research was anchored in tedious work as our co-authors took a deep dive into studies and reports hosted on the Food and Agriculture Organization of the United Nations (FAO) document repository, supplemented by an ad hoc exploration of additional literature.
The FAO is an intergovernmental organization that, among other things, collates worldwide fisheries data. We extracted more than 9,000 reports of fish species in bottom trawl catches, spanning from 1895 to 2021.
The first of our worrying findings is that a huge number of species are affected. We documented around 3,000 different fish species in bottom trawl catches but our modelled estimates suggest the true number could be double that.
Our data also showed that bottom trawls extract all or most species in some fish families. These include both the ocean’s most nutritious and commercially critical fish, such as jacks and croakers, and rare, distinct fish such as giant guitarfish and plough-nosed chimera.
Our second discovery is that many of the species we documented are already known to be of conservation concern. Among those on the International Union for Conservation of Nature’s (IUCN) Red List, about one in seven are classified as threatened or near-threatened with extinction. Bottom trawling was also cited in threat assessments for two-thirds of those species.
A giant guitarfish is among the species being caught by bottom trawling. (Sarah Foster)
Insufficient data
Our third finding was that there is limited information on the conservation status for many of the fish caught in bottom trawls. About one-quarter of the species we recorded were listed as “data deficient” or “not evaluated” by IUCN, meaning their conservation status is essentially unknown.
People tend to focus on the threatened species, which certainly need our attention; seahorses among them. However, we also need to be concerned about the species in trawls that lack conservation assessments, which may also be faring badly.
Finally, we found that many species are not even being recorded. Our database includes relatively few records of smaller demersal species (animals that live near the bottom of the sea), with fisheries often just lumping them together as “various” or “trash fish.”
As many fish are so often overlooked or ignored in catch records, we often don’t actually know what bottom trawlers are catching. When species are not recorded, we lose critical information about biodiversity, population status and ecosystem impacts, not to mention the loss of resources that people depend on for food and livelihoods.
Bottom trawl fisheries should be required to demonstrate that they are ecologically, economically and socially sustainable before being considered acceptable. As it stands, the burden of proof falls on those trying to demonstrate harm — not on the industry causing it. This needs to be reversed, paying full attention to all the fish in the nets.
The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.
Longtemps pensés uniquement à l’aune de leur fertilité, les sols sont aujourd’hui redécouverts pour leur statut de puits de carbone. Autrement dit, leur capacité à séquestrer le carbone en fait des contributeurs de premier plan à la lutte contre le changement climatique. Une étude sociologique menée auprès de scientifiques, politiques et acteurs publics territoriaux met en évidence cette redéfinition climatique des sols et ses conséquences concrètes.
Si le rôle climatique des forêts comme puits de carbone est connu depuis les années 1990, celui des sols l’est moins. Ces derniers contiennent pourtant trois fois plus de carbone et jouent un rôle clef dans son cycle global. Lors de la COP21 à Paris en 2015, le gouvernement français avait lancé l’initiative 4 pour 1000 afin d’encourager les agricultrices et agriculteurs à séquestrer du carbone dans les sols.
En augmentant les stocks de carbone des sols, la démarche visait à compenser les émissions fossiles tout en améliorant la qualité des sols. Mais la capacité des sols à séquestrer du carbone requiert l’adoption de pratiques agricoles spécifiques : implantation de couverts végétaux, réduction du labour, plantation de haies ou d’arbres, ou encore restitution à la terre des résidus de cultures comme les pailles. La préservation des zones humides, des forêts et des prairies, dont les sols sont particulièrement riches en carbone, contribue aussi à atténuer le changement climatique.
Comment ces diverses pratiques de séquestration du carbone modifient-elles les conceptions des sols ? L’équipe du projet ANR Posca a mené une vaste enquête sociologique pour répondre à cette question. À la clé, plus de 250 entretiens approfondis avec des scientifiques, des décideurs publics, des agents de collectivités territoriales et des acteurs agricoles.
Cette enquête montre que l’essor des pratiques de séquestration s’accompagne d’une redéfinition climatique des sols. Longtemps considérés principalement sous l’angle de la fertilité agricole, les sols sont désormais également vus comme des puits de carbone. Et cela, dans une large gamme de mondes sociaux : la recherche scientifique, mais également les politiques agricoles nationales et les territoires.
Les chercheurs ont notamment adapté leurs questions de recherche afin d’interroger les processus qui permettent de stabiliser le carbone dans les sols. Cela a permis de faire évoluer les modèles représentant ces mécanismes, dans le but de contribuer à améliorer les scénarios climatiques. Ils ont également créé de nouvelles infrastructures de surveillance des stocks de carbone dans les sols à l’échelle nationale, et noué de nouvelles collaborations avec les sciences du climat.
Les enjeux climatiques ont par ailleurs conduit les scientifiques des sols à produire de nouveaux travaux d’expertise, à la fois dans le cadre du Groupe d’experts intergouvernemental sur l’évolution du climat (GIEC) à l’échelle internationale, mais aussi à l’échelle nationale, pour estimer le potentiel de stockage du carbone dans les sols. Ces réorientations de leurs travaux permettent de fournir des éléments d’appui aux politiques publiques et aux développements économiques liés à la séquestration du carbone.
Les chercheuses et chercheurs ont ainsi transformé leurs agendas et pratiques de recherche pour produire des connaissances qu’ils estiment utiles à la lutte contre le changement climatique. Mais cela n’a pas été sans créer de nouvelles tensions au sein de cette discipline, notamment autour de la question de la non-permanence du carbone dans les sols.
Des crédits carbone pour les sols agricoles qui stockent
De nouvelles conceptions climatiques des sols sont également véhiculées par l’initiative du 4 pour 1000, depuis sa publication fin 2015 par le ministère de l’Agriculture. Cette initiative tire son nom du calcul selon lequel augmenter tous les ans d’environ 0,4 % le stock global de carbone contenu dans les sols permettrait de compenser l’augmentation annuelle des émissions de gaz à effet de serre.
Plus récemment, une étude coordonnée par Inrae a permis de préciser le potentiel de séquestration des sols nationaux. Celui-ci équivaut à environ 40 % des émissions de gaz à effet de serre du secteur agricole en France – soit 6,5 % du total des émissions nationales. Certes, c’est loin de pouvoir compenser l’ensemble des émissions nationales de gaz à effet de serre, mais cela reste une contribution bienvenue à l’effort d’atténuation, que le gouvernement souhaite encourager.
Cette promesse de séquestration est d’autant plus mise en avant aujourd’hui qu’elle permet de repositionner le secteur agricole comme solution au changement climatique, dans une période où celui-ci est fortement critiqué – quand bien même le secteur reste émetteur net de gaz à effet de serre.
Le gouvernement français a ainsi lancé son label bas carbone (LBC) fin 2018. Cadre de certification des réductions d’émissions et des pratiques séquestrantes, il vise, entre autres, à rétribuer les efforts des agriculteurs qui adoptent de nouvelles pratiques vertueuses. Il permet notamment d’attester du nombre de tonnes de carbone séquestrées, pour que les agriculteurs puissent vendre les crédits carbone correspondant à des entreprises ou des collectivités. Le principe est celui du marché carbone : ces acheteurs pourront, à leur tour, alléguer d’une contribution à l’effort d’atténuation du changement climatique.
Le label bas carbone contribue à véhiculer une vision des sols agricoles comme puits de carbone optimisables grâce aux changements de pratiques agricoles. Pour autant, son impact reste actuellement limité, car les projets qui en relèvent mobilisent finalement très peu la séquestration du carbone, mais plutôt des pratiques de réduction des émissions.
Des collectivités qui quantifient le carbone dans leurs sols
Depuis 2016, une nouvelle législation exige par ailleurs que les collectivités de plus de 20 000 habitants évaluent le potentiel de séquestration de carbone par les forêts et les sols. Elles doivent ainsi concevoir un plan climat air énergie territorial (PCAET) qui mesure, entre autres, la quantité de carbone contenu dans les sols et détaille des stratégies possibles pour augmenter ces stocks. La réglementation reste cependant muette sur les moyens et les outils utiles pour quantifier et gérer les stocks de carbone des sols.
Dans ce contexte, les collectivités territoriales mobilisent divers instruments de quantification du carbone des sols. Les analyses de terre étant longues et coûteuses à mettre en œuvre, ces outils reposent généralement sur des données et des modèles numériques qui prédisent l’évolution des stocks de carbone en fonction de différents scénarios de gestion.
L’Ademe a par exemple développé l’outil Aldo, qui permet aux fonctionnaires territoriaux et aux bureaux d’études d’obtenir aisément des valeurs de stocks de carbone.
Agro-Transfert, un organisme de recherche et développement agricole, a également créé l’outil Simeos-AMG. Initialement pensé pour aider les agriculteurs à conserver des sols fertiles et riches en matière organique, il est désormais mobilisé par les professionnels agricoles pour connaître l’impact carbone de leurs pratiques, ainsi que par certaines administrations territoriales pour concevoir leur plan climat air énergie territorial. Le carbone des sols devient ainsi un nouvel objet d’action publique dans les territoires.
Vers une redéfinition climatique des sols
Notre recherche a ainsi mis en lumière la façon dont les sols se trouvent redéfinis à l’aune des enjeux climatiques, que ce soit dans les mondes de la recherche scientifique, des politiques agricoles nationales ou des territoires. Nos résultats montrent que cette climatisation des sols se traduit d’ores et déjà concrètement par de nouvelles pratiques, des engagements et des instruments inédits qui se développent.
Les sols ne sont par ailleurs pas réduits au rôle de simples réservoirs de carbone à optimiser. L’enquête révèle que nombre d’acteurs, en particulier scientifiques, rappellent que ce carbone à séquestrer peut être relargué dans l’atmosphère, notamment si les pratiques agricoles de séquestration ne sont pas maintenues sur le long terme.
De ce fait, il est crucial d’inscrire ces changements dans le long terme. Et cela d’autant plus que ces pratiques sont aussi alignées avec des gains en termes de fertilité et de qualité des sols, les principales préoccupations dont ils faisaient jusqu’ici l’objet. La redéfinition climatique des sols relie ainsi les questions d’atténuation climatique avec les questions de maintien de la fertilité agricole et de conservation de la qualité des sols.
Céline Granjou a reçu des financements de l’Agence Nationale de la Recherche pour le projet ANR-20-CE26-0016
Antoine Doré a reçu des financements de l’Agence Nationale de la Recherche.
Hélène Guillemot a reçu des financements de l’ANR pour le projet POSCA.
Laure Manach a reçu des financements de l’Agence nationale de la recherche et de la Fondation TTI.5.
Léo Magnin a reçu des financements de Agence Nationale de la Recherche (ANR) dans le cadre du projet POSCA.
Robin Leclerc a reçu des financements de l’ANR
Stéphanie Barral a reçu des financements de l’Agence Nationale de la Recherche.
Agriculture is the lifeblood of Africa. More than 60% of African households depend directly or indirectly on the land for their livelihoods. And the continent has nearly 60% of the world’s uncultivated arable land.
Farming is a fragile sector, however. It has to deal with climate change, market volatility, weak infrastructure and demographic pressure. Addressing these challenges requires political commitment and investment. It also requires science, innovation and high-quality research.
I have been involved in scientific research, particularly agricultural research, for more than four decades. My roles have included researcher, member of multiple science academies, director general of the Africa Rice Center/CGIAR, and Senegal’s minister in charge of agricultural research.
Throughout these years, one criticism has repeatedly surfaced: agricultural research is often perceived as expensive while delivering little for people. This perception is widely shared and frequently echoed in political and media debates.
Based on my experience, I believe the criticism rests on a questionable assumption: that the impact of science depends exclusively on those who produce it. When innovations fail to change the world, scientists themselves are often presented as the culprits.
The reality is far more complex. The history of agricultural transformation across the world shows that research alone never changes societies. Impact follows when an agricultural ecosystem effectively connects science to producers, markets, finance, institutions and public policy.
International institutions have highlighted the difficulties many developing countries face in turning scientific knowledge into development. The reasons include weak innovation ecosystems, too little infrastructure and limited institutional coordination.
An example of what success looks like is the Green Revolution in Asia. Scientific breakthroughs improved wheat and rice varieties which transformed agriculture. It was not simply because the science was strong. There were other factors too. They included governments investing in irrigation, extension services, rural infrastructure, credit systems and market organisation.
In India and Vietnam, for example, science operated within a coherent system linking researchers, farmers, institutions and markets.
Science generates knowledge, informs policies, stimulates innovation and opens new possibilities. But it does not change societies on its own.
The missing parts
Recent decades have brought advances on a number of fronts. In seeds, irrigation, soil fertility management, climate adaptation, biotechnology, digital agriculture, agroecology and sustainable food systems.
African researchers, universities and international agricultural research centres have contributed enormously to this progress.
Rwanda and Ethiopia provide useful examples of how coordinated ecosystems can speed up change. In both, stronger links between research, extension systems, public investment and farmer support mechanisms have made a difference. They have contributed to faster uptake of new technologies. And they have led to productivity gains in several strategic crops such as maize, rice, cassava, beans and soybeans.
Another example is rice. During my years at AfricaRice, I saw major scientific advances in rice research. This included the development of New Rice for Africa varieties.
These resulted from years of scientific work combining the high productivity potential of Asian rice with the resilience of African rice, particularly its tolerance to drought, poor soils and local climatic stresses. It wasn’t easy, because the two rice species are genetically distant.
Farmers quickly took up the new varieties. Farmer incomes and food production improved in countries where governments, seed systems, extension services and development partners worked together. In Uganda, Guinea and several west African countries, coordinated programmes helped accelerate adoption among smallholder farmers.
These examples show that effective agricultural innovation will only be adopted and scaled if several conditions are met together. These include:
access to inputs and technologies
accessible financing
efficient extension services
functioning infrastructure
organised markets
coherent, predictable public policies.
Without these conditions, innovations often remain confined to research stations, pilot projects or scientific publications. Where seed systems, rural financing or market organisation are weak, good science makes little difference.
In several African countries, farmers aren’t using improved seed varieties because they can’t get certified seeds at scale. Likewise, promising innovations in irrigation, post-harvest technologies or digital agriculture have struggled because of weaknesses in infrastructure, rural credit or institutional coordination.
What’s needed
Debates on agricultural research in Africa must go beyond simplistic criticism. Agricultural research should not be viewed as a cost. Rather it is a strategic investment in food security, economic sovereignty, environmental sustainability, public health, social stability and human dignity.
Blaming science for lacking impact masks the weaknesses of broader development systems.
As Africa faces the defining challenge of the 21st century – feeding its population without destroying the planet – it would be a mistake to weaken scientific research. The continent must instead strengthen alliances between science, policy, finance, private sector actors, farmers, universities and civil society.
Across Africa, emerging innovation platforms show that when these actors work together, scientific advances can create tangible economic and social change. The challenge now is to broaden this beyond isolated successes.
In the end, the impact of science is a collective responsibility.
And science can only change the world when societies decide to give it the means to do so.
Pape Abdoulaye Seck served as director general of the Africa Rice Center/CGIAR and was Senegal’s minister in charge of agricultural research.
Source: The Conversation – in French – By Catherine Régis, Professeure titulaire, Faculté de droit, Chaire Canada-CIFAR en IA et Chaire de recherche du Canada en droit et politiques de la santé, Université de Montréal
Les États sont en compétition afin de développer le plus rapidement possible des modèles d’intelligence artificielle (IA). Les intérêts nationaux et internationaux des différents acteurs divergent en fonction de leurs enjeux et réalités propres. Ce développement tous azimuts de l’IA suscite des préoccupations croissantes. Un groupe d’experts a été créé afin de dépasser les rivalités et de développer un consensus scientifique à l’échelle de la planète autour de l’IA.
Le 3 février 2026, 40 expertes et experts ont été nommés parmi 2600 candidatures. Sélectionnés pour un mandat de trois ans par la communauté internationale, les candidats constituent ainsi le premier « Groupe scientifique international indépendant de l’intelligence artificielle » (Groupe d’experts). Ce groupe de haut niveau, co-présidé par le professeur québécois Yoshua Bengio, est chargé de rédiger un rapport annuel fondé sur des données fiables synthétisant les recherches existantes sur les « promesses, risques et répercussions » de l’IA, sans toutefois devoir se prononcer sur les enjeux, pourtant de taille en gouvernance mondiale de l’IA, liés au militaire.
Ce groupe constitue un cas d’étude particulièrement intéressant pour les travaux que nous menons dans le cadre de la Chaire en Diplomatie scientifique et gouvernance mondiale de l’IA à l’Université de Montréal puisqu’il représente un exemple prometteur de diplomatie scientifique appliquée à l’IA.
Les dangers de l’IA
Que ce soit en raison de leur conception, de leur mise au point ou de leur utilisation, les systèmes d’IA présentent des risques aujourd’hui connus et documentés.
Par exemple, les systèmes d’IA utilisés pour le diagnostic médical peuvent reproduire des biais présents dans les données sur lesquelles ils sont entraînés, avec des taux d’erreur plus élevés pour les femmes et les personnes racisées.
De même, les outils de génération de contenu permettent de produire en quelques secondes des milliers de faux articles ou de fausses déclarations, saturant l’espace public de désinformation, difficile à contrer. Quant aux systèmes de reconnaissance faciale déployés par certains États, ils permettent une surveillance de masse sans consentement, avec des erreurs d’identification documentées ayant conduit à des arrestations injustifiées.
Dans ces circonstances, la création du Groupe d’experts apparaît plus qu’opportune puisqu’il a pour mandat de fournir des connaissances scientifiques vis-à-vis des risques de l’IA et cela de manière indépendante, sans ingérence politique.
Une impasse persistante
Les effets de l’IA dépassent largement les frontières des pays, ce qui plaide en faveur d’une réponse mondiale organisée.
Ces différentes initiatives ont posé les premières pierres pour une gouvernance mondiale de l’IA. Pour autant, ces efforts multilatéraux sont limités : peu d’obligations juridiques pour contraindre les entreprises et les États, peu de moyens d’obtenir réparation en cas de violations de ces obligations et, surtout, de nombreux États sont en dehors du champ d’application des quelques normes contraignantes qui existent pour encadrer les systèmes d’IA et les données qu’ils mobilisent à l’échelle internationale.
C’est notamment le cas des États-Unis ou de la Chine. La course à l’IA ayant pris de l’ampleur et les États ayant affirmé des positions parfois complètement antagonistes (ex : réguler versus libre développement), ces dynamiques nous ont plongés dans une impasse qui essouffle les efforts de gouvernance mondiale de l’IA. La perspective d’un traité international sur l’IA regroupant tous les États semble vaine pour le moment.
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L’ONU choisit la science
C’est dans cette impasse que s’inscrit le pari du Groupe d’experts, qui se distingue des initiatives précédentes puisqu’il ne vise aucunement à dire ce qu’il faudrait faire (caractère normatif), mais à évaluer scientifiquement les risques et les opportunités de l’IA. L’ONU mise ainsi sur la science pour développer des consensus à l’échelle de la planète.
Ce pari peut surprendre au regard du contexte actuel où la science doit faire face à des attaques croissantes sur sa légitimité et à une perte de confiance observée depuis la pandémie de Covid-19. Pourtant, c’est précisément parce que l’IA est une technologie complexe et évolutive que seule une évaluation scientifique rigoureuse permettra d’en saisir les risques réels, d’en anticiper les effets et d’éclairer, ensuite, les décideurs.
Le Groupe d’experts réunit des profils délibérément variés, avec des expertises multidisciplinaires (apprentissage automatique, cybersécurité, droits humains, gouvernance des données…). Cela lui permet de produire des évaluations qui dépassent le seul champ technique pour intégrer les dimensions sociales et éthiques de l’IA.
Cependant, les experts ne disposeront d’aucun pouvoir décisionnel en matière de politiques publiques. Les rapports qu’ils produiront viseront plutôt à fournir un baromètre scientifique sur les avancées de l’IA pour ensuite permettre aux États de prendre les décisions appropriées sur cette base. Le Groupe d’experts représente ainsi une expression récente d’efforts en matière de diplomatie scientifique.
Un laboratoire inédit pour observer la diplomatie scientifique
Entendue au sens large, la diplomatie scientifique constitue « l’ensemble des pratiques se situant à l’intersection de la science et de la diplomatie », dont la finalité est d’apporter une contribution significative aux défis mondiaux. En l’occurrence, étant notamment appelé à éclairer les discussions engagées lors du Dialogue mondial, une rencontre annuelle entre les gouvernements et les parties prenantes sur l’IA, le Groupe d’experts constitue une forme concrète de diplomatie scientifique.
Ce qui confère au Groupe d’experts un intérêt particulier, au-delà de ses livrables, c’est qu’il va se positionner comme un acteur incontournable de la diplomatie scientifique liée à une technologie numérique de pointe en temps réel. Cela est d’autant plus pertinent qu’il va permettre d’observer la diplomatie scientifique telle qu’elle s’exprime dans une période de reconfiguration.
D’ailleurs, sur ce point, le secteur privé occupe actuellement une place significative tant dans la production scientifique que dans la diplomatie. Par exemple, les géants de la Tech ont participé aux différents sommets sur l’IA, qui sont des rendez-vous pour définir les priorités mondiales et influer sur les négociations et décisions à venir.
Face à des acteurs privés dont l’influence sur les négociations internationales n’a cessé de croître, le Groupe d’experts incarne une logique différente : celle où les conclusions sont guidées par la rigueur scientifique plutôt que par des intérêts économiques. Toutefois, le Groupe ne cherche pas à exclure le secteur privé, qui reste une source essentielle d’innovation.
Les experts éclaireront, mais seront-ils écoutés et suivis ?
Reste la question centrale : la science parviendra-t-elle à faire converger des intérêts nationaux et mondiaux qui peinent à se rejoindre et, surtout, les évaluations scientifiques trouveront-elles écho auprès des décideurs qui restent libres de les ignorer ?
La réponse dépendra en grande partie de la capacité du Groupe à faire valoir ce qui constitue l’un de ses seuls leviers réels : l’expertise reconnue de ses membres, leur capacité à colliger des données de qualité tirées tant de la recherche universitaire que de l’industrie où l’IA de pointe est généralement concentrée et leur indépendance formelle.
Son premier rapport, attendu pour juillet prochain, constituera bien plus qu’un document technique : en moins de six mois d’existence, le Groupe d’experts testera en conditions réelles si la science peut encore faire office de langage commun entre des États aux intérêts profondément divergents, ce qui constituera un laboratoire d’étude précieux sur la diplomatie scientifique de demain dans un contexte géopolitique sous forte tension.
Catherine Régis a reçu des financements des Fonds de recherche du Québec, de CIFAR, des Instituts de recherche en santé du Canada et du Conseil de recherches en sciences humaines du Canada.
Gaëlle Foucault a reçu des financements de IVADO pour ses recherches postdoctorales.
Michel Audet ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d’une organisation qui pourrait tirer profit de cet article, et n’a déclaré aucune autre affiliation que son organisme de recherche.
Many countries across Africa have embraced universal basic education policies in recent decades. But recent data has revealed that more than 100 million children and adolescents remain out of school, out of a total potential population of 469 million. The latest statistics suggest that after some years of progress, the situation is deteriorating. Education and youth empowerment scholar Moses Ngware and his co-researchers recently carried out an analysis of trends going back 25 years. Their main findings are set out below.
What are the school attendance trends in Africa across all age groups?
In 2000, the number of out-of-school children in primary school, lower secondary and upper secondary was above 100 million. It was down to about 90 million in 2014, and then up again to 100 million by 2025.
Viewed against Africa’s high population growth of above 2.5%, these absolute numbers suggest that school participation is not keeping pace.
Nevertheless, between 2000 and 2024, the proportion of out-of-school children and adolescents declined at all education levels. It fell from 37% to 20% for primary schools; from 47% to 35% for lower secondary and from 56% to 47% for upper secondary school-age children. This is despite the absolute numbers of out-of-school children remaining high.
Countries that showed greatest improvement included Côte d’Ivoire, Ethiopia, Guinea, Madagascar and Mozambique. Improvements were driven by at least two main factors. First, targeted policy responses that enabled them to achieve good coverage in a short time. Second, a strong political will combined with a multi-sectoral approach. The approaches included combining conditional cash transfers for households, food supplies, expanding access to schools and implementing universal education policies that reduce cost of schooling for households.
On the other hand, there are countries that made little or no progress. They include Angola, Cape Verde, Lesotho, South Sudan and Zimbabwe. The main drivers of the low progress are:
political instability, as seen in South Sudan
poor economic performance, as witnessed in Zimbabwe
the high opportunity cost of schooling, as seen in Lesotho, where boys drop out due to poverty related coping mechanisms, including herding cattle, with only one in every five boys completing grade 12.
What are the notable changes in recent years?
In the past five years, we have seen a steady increase in absolute numbers of out-of-school children and adolescents from 95 million to 100 million, with an average of about 1 million children either not transitioning from primary to secondary school or leaving school or not joining school at all.
There are two main drivers of such a trend. First, finance – the fizzling effect of the universal basic education subsidies of the early 2000s. These subsidies made basic education affordable to many households. Of the 42 African countries with free education in their policies, only three were in a position to offer free schooling in 2025. Donor funding of education by multilateral organisations has also been reduced, with education aid in Africa declining by 7% in 2024. Second, the negative impact of COVID-19, with about 10 million who left school due to the lockdowns never to return, for various reasons, including forced marriages among girls and child labour for boys.
Across all the schooling levels, higher than before rates of out-of-school children and adolescents were observed in the Sahel region, in Central African Republic, Chad, Mauritania and northern Nigeria. These countries or regions are characterised by politically motivated violence, harsh climatic changes and a history of low school participation.
Why is school completion important for societies?
The main benefits to societies of school completion include transition to decent work, girls’ empowerment, and improved health outcomes. An additional year of schooling increases an individual’s lifetime earnings by about 10% on average, with a potential to increase an individual’s purchasing power. Such benefits can also trickle down to households through providing household financial stability and enhanced family support.
For girls, school completion is critical for participation in decision making at societal level. Research shows that a woman’s power to make decisions, such as education for her children or where to invest, increases with education attainment. This has a bearing on economic independence and gender equity within the society.
Furthermore, and related to these two benefits, children of mothers who have completed secondary education have a 45% lower under-3 mortality rate. This implies that such children have about half the risk of death before age 3 compared to those born to mothers with no education.
What are the gender dynamics?
By 2025, the proportion of males that were out of school, at 51%, was only slightly higher than that of females. However, the out-of-school female rate was on the rise – up by two percentage points in 10 years.
If this growth continues, then the proportion of out-of-school females will overtake that of males in the coming years. This will compound the vulnerabilities disadvantaged girls face in their schooling journey and transition to work.
In addition, the gains made in the last three decades in closing gender gaps in education will be eroded. Eroding the gains made in education has severe consequences, especially for girls. For instance, we are likely to see an increase in females getting married much earlier, and child bearing among adolescents may also increase.
What lessons can we learn from the better-placed countries?
There are a number of important lessons to be learnt from countries that have lowered the number of out-of-school children and adolescents.
First, Algeria, Ghana, Kenya and Rwanda have relied on a strong national policy framework backed by political good will, high-level central coordination and donor-partner support.
Second is the importance of targeted social support such as school feeding and conditional cash transfers. Close evaluations using hard data are needed.
Fourth is the lesson that affirmative action for vulnerable populations is an invaluable investment. These populations include disadvantaged girls, children from remote rural areas, children with disabilities, and children from poor households.
Finally, there are other interventions that can add value depending on the context. These include reducing travel distance through expanding infrastructure, and flexible school entry, such as late entry to improve participation. Another is catch-up programmes, which means accelerating progression to recover lost time and learning.
Moses Ngware receives funding from.
African Population and Health Research Center (APHRC)
Malaria, diarrhoea and pneumonia are preventable childhood diseases that are major causes of death in young children. They’re transmitted largely in and around the home, where children spend most of their time.
For example, around 80% of malaria transmission in Africa occurs when people are bitten by malarial mosquitoes indoors at night. Diarrhoea results usually from food and water that’s been contaminated by faeces. It can also be spread through poor hygiene. Pneumonia is spread through overcrowding and poor ventilation, and is exacerbated by indoor air pollution.
We are an international group of specialists from different fields including architecture, communications, global health, medical anthropology, public health entomology, engineering and statistics.
To see if it might be possible for a newly designed house to help prevent malaria, pneumonia and diarrhoea in children, one of us (Danish architect Jakob Knudsen) came up with a new design. We called it the Star home.
This house costs 24% less in materials than a conventional single-storey cement-block house. It also uses 73% less concrete, and generates 57% less embodied carbon (the amount of carbon emissions released from the time raw materials are turned into building materials for the house to the end of the home’s life). Our analysis revealed a fourfold return on investment over 50 years once health, water, cooling and energy savings are accounted for.
The features of the Star home are:
Double-storey buildings. Bedrooms are positioned on the upper floor, away from mosquitoes, which are most abundant at ground level.
Cross-ventilation, where air passes across the room. We increased ventilation inside the home by using walls made of shade net, instead of solid walls. These also cooled sleeping areas and deterred mosquitoes from entering the room.
Mosquito screens on doors and windows. These screens keep malaria mosquitoes and flies out.
Self-closing doors. These minimise the entry of mosquitoes and flies.
Clean water harvesting, improved pit latrines and improved cooking stoves.
We put the Star home through a three year, peer-reviewed trial to see if it could reduce malaria, diarrhoea and pneumonia among children.
Our findings were startling: After three years, children living in the Star homes had 44% less clinical malaria, 30% less diarrhoea and 18% less pneumonia than those living in traditional houses.
Because they were protected from three serious illnesses, their overall health improved and the children grew taller than children living in traditional houses.
Our study also demonstrated that the new, comfortable Star house has a lower carbon footprint than the cement-block houses that are currently built in sub-Saharan Africa. Put simply, we used less energy to build a Star home than is used in building a typical cement house constructed in a village.
We also found that passive cooling in the Star home made the home more comfortable in hot weather even though it did not have air conditioning, which consumes energy.
Our study demonstrates that small improvements in design are likely to make a major health impact on the lives of children in Africa.
The ground work
We first set about understanding how the pathogens causing the three diseases spread in and around the home.
Malaria: How mosquitoes enter houses has been the subject of research for decades. Research shows that they find people mainly by smell. From far away, they follow the carbon dioxide humans breathe out, and when they get closer, they are guided by smells produced by bacteria on human skin.
Diarrhoea: Houses with a regular supply of clean water, clean food preparation areas, fly-proof latrines and kitchens can help reduce the spread of this disease.
Pneumonia: This is spread through air-borne pathogens and is made worse by smoke-filled kitchens which damage the lungs.
We then developed the Star homes and tested whether they were healthier by carrying out a randomised controlled trial in southern Tanzania, an area with high levels of malaria.
In the trials, we recruited children under 13 years of age and randomly allocated them to 110 Star homes and 513 traditional mud and thatched-roof houses.
These children were followed weekly for signs of illness for three years and the data from the clinical trial were analysed.
Africa’s housing boom: a chance to build healthier homes
Africa’s population is the most rapidly expanding in the world, with the current population of 1.5 billion people expected to increase to 2.7-3.7 billion by 2070.
Hundreds of millions of new homes will need to be constructed soon.
There has never been a better time to build healthier homes on the continent. Improvements in rural housing are increasing at a fast pace.
Governments can take a number of steps to help. For example, they can facilitate the construction of better rural homes by assuring ownership rights (titles). These are essential for homeowners who want to apply for loans to carry out healthy home improvements. Governments could also reduce import taxes on fly screening, and provide advice and support for the construction of healthy homes.
We hope that this study will stimulate further innovation by people working in the built environment who could collaborate with local communities to construct healthier homes for rural people in low- and middle-income countries. Simple improvements in housing can have profound impacts on improving public health.
(About our team: Salum Mshamu, a Tanzanian scientist, carried out trials on the Star home as part of his PhD studies at Oxford University. Jakob Knudsen has been designing healthy and cooler homes in the tropics, particularly in Tanzania, for over 30 years. Lorenz von Seidlein is a paediatric clinician who has studied the epidemiology and control of childhood infections, principally malaria, in different parts of the tropics. Steve Lindsay has over 40 years of experience working on the control of mosquitoes and flies, including running clinical trials of housing interventions.)
Emeritus Professor Steve Lindsay receives funding from Hanako Foundation, Singapore, BBSRC GCRF Network Grant (BB/R00532X/1) and Sir Halley Stewart Trust.
The Royal Danish Academy / Jakob Brandtberg Knudsen receives funding from Hanako Foundation for the Star Homes Project
The Star Homes project has been funded by the Hanako Foundation, Singapore.
Salum Ahmed Mshamu does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
Source: The Conversation – USA (2) – By Nicole Van Lier, Assistant Professor of Urban and Environmental Studies, Loyola Marymount University
Workers repair a water pipeline that dates back to the 1930s. In the coming years, utility bills in Detroit are likely to rise to pay for upgrades to aging infrastructure. Jim West/UCG/Universal Images Group via Getty Images
Beginning in July 2026, Detroiters will be paying higher water and sewer bills.
Residents at GLWA’s last rate hearing spoke of their difficulty keeping up with utility bills. For low-income customers across the GLWA system, rate increases aggravate a deeply entrenched water affordability crisis.
Utility bills are the primary source of revenue for public water and wastewater systems. Yet both the Detroit Water and Sewerage Department, or DWSD, and GLWA are caught in what utility experts call an affordability gap. That is, the discrepancy between what it costs to maintain essential infrastructure and what ratepayers can reasonably afford.
Utilities across the country are facing down a similar contradiction. For DWSD customers, the gap is wider still because they carry a greater burden for water quality improvements that benefit the wider metropolitan region.
About three-quarters of a DWSD residential water bill pays for wastewater and stormwater treatment. These revenues also help to maintain Detroit’s wastewater treatment plant, which serves the city and 76 suburban communities.
My research, which combined archival research and interviews with state regulators, Detroit city staff, DWSD and GLWA representatives and grassroots water affordability advocates, documents how Detroit’s water affordability crisis involves a less visible form of environmental injustice. This term often describes uneven exposure to pollution or other environmental harms. Detroit’s case raises a different question: Who pays to keep local waterways clean?
Regionalizing Detroit’s wastewater system
Detroit’s wastewater treatment plant is the largest single-site treatment facility in the country. While suburban communities own and operate local sewer systems, they are connected by a regional sewer network that stretches across 944 square miles of Wayne, Oakland and Macomb counties. This network conveys raw sewage to the treatment plant in Detroit.
The wastewater system was not initially designed to serve the metropolitan region, however. It was expanded through the 1950s-70s to help suburban communities address new state wastewater mandates.
The postwar period is well known for its economic boom, but it also ushered in important social, political and environmental shifts.
Following World War II, for example, local waterways were slick with both industrial and municipal wastes. Polluted waters posed a threat to the safety of people’s drinking water and to Detroit’s water-intensive industrial manufacturers.
In response, Michigan revamped its water pollution law in 1949, requiring cities, towns and villages to install wastewater treatment. Some suburbanizing communities resisted these mandates. They argued their tax bases, then only a few thousand residents, were insufficient to finance such costly infrastructure.
Meanwhile, civil rights organizers in Detroit and across the nation struck down racist segregation laws through the 1960s. Black families began moving into historically white neighborhoods. Following Detroit’s turbulent summer of 1967, demand for suburban housing in all-white communities skyrocketed. More than 40,000 white residents left Detroit for the suburbs that year, a figure that doubled in 1968.
This phenomenon, known as white flight, not only spurred suburbanization but left the tri-county area largely segregated by race and class.
The convergence of stricter water quality laws, suburban growth and white flight also had implications for the wastewater system and its management.
By the late 1950s, Michigan’s Department of Public Health had begun denying sewer permits to developers building in places with insufficient wastewater treatment. Permit denials helped to enforce the state’s wastewater mandates. They became known as “construction bans” for the way they slowed suburban growth.
The quickest way to resolve these “bans” was to route suburban sewage to Detroit. By 1974, DWSD provided wastewater treatment to more than 70 suburban communities across a deeply segregated service area.
In 2014, demonstrators gathered to protest the city’s widespread water shutoffs, which left thousands of Detroit residents without water due to unpaid bills. Photo by Joshua Lott/Getty Images
An uneven burden for improving public infrastructure
In addition to ongoing rate disputes, suburban politicians introduced “takeover bills” in the state Legislature. The goal was to transfer control of DWSD’s infrastructure to a new regional authority. Both tactics persisted through the 1980s and ’90s, forcing DWSD to make compromises that shifted more costs onto Detroit ratepayers.
A prime example is the 1999 rate settlement agreement that resolved a decade of suburban rate disputes over DWSD’s stormwater charges. Known as “the 83/17 split,” the agreement assigned 83% of stormwater improvement costs to Detroit, while suburban customers shared the remaining 17%, divided 76 ways.
The rates under dispute were introduced to meet new state regulations targeting combined sewer overflows. These overflows occur when pipes release raw sewage and stormwater into waterways during heavy rain. Suburban officials argued for a reduced share of improvement costs. They pointed out many of their sewer systems already separated storm and sanitary pipes, reducing the occurrences of combined sewer overflows. Yet state-mandated improvements required expanding shared infrastructure, not simply combined sewer overflow outlets in Detroit.
GLWA’s own wastewater master plan documents suburban stormwater entering regional sewers long after the 83/17 split was established. Suburban sprawl also paved over vast stretches of land, funneling more runoff into the system.
Nevertheless, the settlement reduced the suburban share of combined sewer overflow improvement costs to 17%. DWSD was ordered to set aside US$10.6 million to reimburse suburban customers for previous stormwater charges above the 17% threshold.
For the past 25 years, Detroiters have borne the bulk of stormwater upgrades – a capital program that has exceeded $1.5 billion.
The approximately 680,000 residents of Detroit have borne these costs despite accounting for only 23% of GLWA’s 2.9 million wastewater customers.
A push toward water affordability
The 83/17 split remains in place today. It was grandfathered into GLWA’s 40-year lease agreement with DWSD that took effect in 2016.
While DWSD continues to provide local water and sewer service to city residents, the lease transferred fiscal and operational control of regional water and wastewater infrastructure to GLWA. This means cost-sharing for stormwater improvements will continue to be structured by the 83/17 split for decades to come – unless GLWA consents to renegotiating the deal.
In 2016, Detroit’s blue ribbon panel on water affordability recommended that DWSD revisit how cost is allocated across all users of the system.
DWSD initiated discussions with GLWA in 2020 and 2021 to revisit the terms of the 83/17 split. GLWA officials concluded, however, that existing legal agreements and contracts made the 83/17 split “logistically challenging” to renegotiate. As long as the 83/17 split remains in place, protecting local waterways from combined sewer overflows will continue to exacerbate the water affordability crisis in Detroit.
This is an especially pressing concern now, with state funding for DWSD’s low-income “lifeline rate” program recently exhausted and urban flooding worsening as storms grow more frequent and severe. While DWSD plans to reopen applications to the lifeline plan later this year, the program can support only about 5,000 residents. This is down from almost 30,000 residents it supported in previous years and far below the level of need with 31.5% of Detroiters living below the poverty line.
Organizations such as the People’s Water Board Coalition have spent two decades building coalitions across Michigan to push for a statewide water affordability plan. A statewide plan that pegs water bills to household income could create a more stable and more equitable revenue source for critical wastewater infrastructure in Detroit.
Nicole Van Lier’s research received funding from the Social Sciences and Humanities Research Council of Canada (SSHRC) and the Fulbright Canada Foundation. During her fieldwork, Nicole was a member of the People’s Water Board Coalition.
Currently, the average gas price in the U.S. is $4.50. In Pennsylvania, the average is $4.66, and in Pittsburgh it’s $4.91.
To understand why, and what – if anything – can be done about high gas prices, The Conversation U.S. spoke with Hannah Wiseman, an energy and environmental law scholar whose work focuses on how regulation is designed. She explains who gets hit hardest by high gas prices and why relief is so hard to come by.
How do rising gas prices hit low-income Pennsylvanians differently than middle- or upper-income residents?
Low-income people typically have a limited monthly budget, with fewer or no savings to draw from. Each essential expense is a portion of an individual’s or family’s fixed budget, and when an essential expense rises, it eats up more of this fixed budget. For the costs of fuel and electricity, this is called the “energy burden” – the percentage of someone’s income that goes to energy costs. The higher the cost of energy, the more this impacts people’s ability to pay for other essential goods, such as food, medicine and medical care.
Pennsylvania consistently ranks among states with the highest gas prices. What regional conditions make Pennsylvania expensive?
Like any other good, the cost of gas is influenced by the cost of the raw product from which gasoline is refined, crude oil, the costs of operating the facilities that transport and distribute gas, and the amount of retail competition.
As the U.S. Energy Information Administration explains, distance from supply – refineries, ports and pipelines – usually means higher prices. This type of infrastructure is scarcer in the mid-Atlantic region, including Pennsylvania. And some rural areas have fewer gas stations, which can result in less retail competition.
Gasoline prices tend to be lowest in Gulf Coast states, such as Texas, with a current average of $4.01, and Louisiana, with a current average of $3.99, where there are many crude oil refineries and oil pipelines.
Due to lack of public transit, rural Pennsylvania residents rely on their personal vehicles to get to work. aimintang/E+ collection via Getty
How does the lack of reliable public transit in rural areas deepen the inequality issue?
Rural areas tend to have less public transportation – making personal vehicles essential – and people have to drive to their jobs to make ends meet. So when gas prices go up, rural residents often have no option but to fill up their tank at a high cost and potentially forgo other essentials.
Rural populations also have a substantial percentage of individuals defined as the “working poor.” These are low-income individuals for whom getting to work is essential. They are already saddled with high energy burdens, which rise with higher gas prices, and they live in rural areas with few affordable options for getting to work.
Are there existing state or federal programs that help low-income residents offset fuel costs?
Low-income support tends to come from states. Most government programs support home heating costs and utility bill payments for low-income residents; programs are more limited for gasoline. In California during the 2022 spike in gasoline prices the state sent checks to low-income families. Currently, Pennsylvania has no formal legislation in place to assist low-income families with gasoline costs.
Additionally, the H.R. 1 Act erased the $7,500 tax credit for buying electric vehicles. This limited access to EVs widens the gap – wealthier families with electric vehicles can plug in their vehicles and avoid high gas prices, while lower-income individuals lack this option.
What can be done about high gas prices for low-income Pennsylvanians?
Hannah Wiseman is a member of the Center for Progressive Reform. Her research on renewable resources, carbon sequestration, hydrogen, and energy/land use connections has received funding from the Sloan Foundation, Arnold Ventures, the Center for Rural Pennsylvania, the U.S. Department of Energy, and the National Science Foundation.
When it comes to space debris, what goes up is coming down more often – and not safely.
When spacecraft launch, some components, including nonreusable rocket boosters, are jettisoned to decrease weight, leaving them to intentionally burn up as they reenter the atmosphere. Satellites also enter the atmosphere at the end of their life, supposedly burning up. But in many cases, they are not doing so as predicted.
Our materials research group at the University of Wisconsin-Stout is studying the materials that allow reentry debris to survive. We look for ways to safely modify their exceptional heat-resistant qualities to make them safer for atmospheric reentry.
Debris landing on Earth
Reentry debris has fallen on both private and public property around the world multiple times since 2021. Some of the most notable events involve pieces from SpaceX Dragon’s carbon fiber trunk, which stays attached to the crewed capsule until just hours before its reentry. These trunks are larger than a 15-passenger van and used for storage.
A large piece of space debris from a SpaceX Dragon capsule was found by a campsite groundskeeper in North Carolina in 2025.
In addition to trunk debris, carbon fiber components that hold pressurized gases to adjust a spacecraft’s orientation also make up a lot of recovered reentry debris. Some of these most recent recoveries have been in Australia, Argentina and Poland.
Most of the debris that reenters the atmosphere burns up, so why are these pieces making it down to Earth’s surface?
Atmospheric reentry
Satellites such as SpaceX’s Starlink reside in low Earth orbit, typically between 190 and 1,240 miles (300 and 2000 kilometers) above the Earth’s surface. To stay there, they need to move really fast, at about 17,000 miles (27,000 km) per hour. To reach this speed, a rocket with a million pounds of fuel had to accelerate it, and part of this energy is still contained within the satellite’s momentum.
As an object in orbit drifts down, closer to Earth’s upper atmosphere, it starts to collide with air molecules, slowing the object down. The amount of heat generated from this interaction rapidly consumes the satellite, melting metal at over 3,000 degrees Fahrenheit (1,600 degrees Celsius).
More launches
Countries around the world have been launching items into space since the 1950s, so why is reentry a concern now?
Most of these launches came from companies in the United States, such as SpaceX and Rocket Labs. Companies like these, along with those outside of the U.S., have plans for large satellite constellations composed of hundreds of thousands to a million satellites.
The more objects and payloads launched, the more reentry events occur. Satellite operators are required to remove their decommissioned satellites from orbit after 25 years to comply with regulations set in place by international committees. Groups across the world, including the Federal Communications Commission in the U.S., have pushed to shorten the deorbit window to five years. Because of these guidelines, the full influx of reentry debris events from these recent launches will not be felt for another 10 or more years.
The objects launched and policy decisions made today will have a lasting effect on future safety.
Carbon fiber
As the world has progressed technologically, efficiency for launching items into space has too.
Satellites and spacecraft are becoming lighter, stronger and more heat resistant because of materials such as carbon fiber-reinforced plastics and new metals. These strong materials are sought after because they’re lightweight, but they can also cause deorbiting debris to withstand reentry temperatures.
Carbon fiber, once used exclusively in space technology, is now found in common items such as bicycle frames and racing car bodies. It is still the gold standard for fabricating high-strength, low-weight materials for spacecraft components such as rocket fuselages, interstaging – the protective housing found between the rocket stages – and pressure vessels that experience extreme temperatures and high mechanical stress and strain.
Simple metals such as aluminum and steel melt and burn away, while complex materials such as carbon fiber, which is manufactured at up to 5,000 F (3,000 C), burn away unpredictably, changing the way jettisoned components break up upon reentry.
Since the early 2000s, a majority of recovered space debris contains either carbon fiber-reinforced plastic sections or metal components wrapped with carbon fiber. The carbon fiber can act as an unintentional heat shield for heavier, more harmful debris.
This map shows locations where confirmed space debris has been recovered. With the increase in launches, the European Space Agency predicts that future space debris could fall practically anywhere across the world. European Space Agency
Design For demise
Design for demise is a major area of research focused on mitigating the risk of reentry debris. Instead of relying on controlled and meticulously timed deorbits that send components that survive reentry into the ocean at the end of their lives, spacecraft components are engineered to ensure they completely disintegrate while deorbiting through the atmosphere.
Design for demise can take many forms. These range from changing to more heat-susceptible materials to relocating harder-to-burn components to areas of the spacecraft that will be hotter during reentry, or using linkages that break apart at high temperatures to separate structures into smaller components to help them burn up.
With so much focus historically on spacecraft being made from the lightest, strongest and most heat-resistant materials available, it may seem counterintuitive to intentionally make some materials weaker. The key is making materials smarter, so they maintain their strength during their mission but weaken under the heat of reentry.
Matthew Ray’s lab is developing and working toward patenting a system to decrease risk from future carbon fiber based reentry debris.
Reese Hufnagel conducts research on space debris and is developing ways to make future carbon composites safer for use in orbit.
Chances are, you think you do. It’s ubiquitous and iconic. How could you not know it?
But when tested, it turns out very few people can remember all the features of the logo. One study of 85 people found that only about half could pick the correct logo out of a lineup of similar ones. And only one person could correctly draw it.
This isn’t an isolated example. A classic study from 1979 found that people similarly couldn’t draw a penny accurately or pick out a correctly drawn penny from incorrect ones.
People aren’t just bad at remembering things they see all the time, but also in actually knowing how they work. In a 2006 study, many people made significant errors when drawing a bicycle, like putting the chain around the front wheel as well as the back wheel. More than just a forgotten detail, putting the chain around both wheels shows a deeper misunderstanding of how a bicycle works. A bicycle with a chain around both wheels wouldn’t be able to turn.
It turns out people’s knowledge of how the world works is often fragmented and sketchy at best. They systematically overestimate their understanding of everyday devices and natural phenomena. People will tend to give themselves high ratings on how well they understand something, such as how bicycles or zippers work. But when they’re asked to actually explain the mechanics of these objects, their ratings of their understanding typically drop.
Just like how your knowledge of the world around you is imperfect, your knowledge about your own knowledge – also called metaknowledge – is often flawed. My field of cognitive science has been uncovering various gaps in human metaknowledge for decades.
If people are systematically overconfident about how well they understand things, why don’t they notice when they don’t understand something? And what can people do to better recognize the limits of their own knowledge?
Why you think you know more than you do
Researchers have identified several factors behind people’s overconfidence in their knowledge.
One is that people confuse environmental support with understanding: The information is out in the world but not actually in your head. With a bicycle or a zipper, all of the parts are visible to you, and you may confuse this transparency for an internal understanding of how they work. But until you go to use that knowledge by attempting to explain how they work, you may not recognize that you don’t understand how those parts interact.
A second factor is confusing different levels of analysis. People can often describe how something works at a very high level. You know that the engine of a car makes the car go, and the brakes slow and stop the vehicle. But confidence in your high-level understanding of the car may bias you to think you also have a good grasp of the finer details, like how the engine pistons and brake pads work.
Additionally, people can be blind to the ways their knowledge shapes their own perception. In one study, researchers had participants tap out the tune to a popular song. On average, the tappers thought listeners would be able to identify the song about 50% of the time. But when listeners had to identify the tapped song, they actually could identify it only 2.5% of the time. The tappers didn’t realize how much their knowledge was making identifying the song seem easy to them.
This disconnect has consequences beyond whether someone else can understand your Morse code version of a song. When teaching people, whether in formal classroom settings or through casual mentorship, you can sometimes have an expert blind spot: the inability to recognize the difficulties beginners face when learning something you have expertise in.
Building expertise often involves internalizing knowledge to the point where it becomes invisible to you. You draw on knowledge you don’t realize you have, making it hard to relate to learners who lack this knowledge – and, of course, hard for learners to relate to your teaching. You might have experienced this when you’ve gotten partway through explaining something, only to realize you’ve been using jargon you forgot isn’t common knowledge and lost your listener.
How to address metaknowledge failures
Your metaknowledge can fail in two directions: You can think you know more than you do, and you can be blind to how much you’re relying on knowledge you do have. Each calls for a different response to correct it.
When you’re overconfident in your knowledge, the remedy is using that knowledge. You’ll quickly realize how much you actually understand and dial down your confidence. Challenging yourself to actually try to walk through how something works is a great exercise in intellectual humility – that is, recognizing that you may be wrong – and can keep you from getting out over your skis.
Building a greater appreciation for what you know is more difficult. You can’t simply unlearn what you’ve internalized. But what this challenge shows is that, to some extent, knowing a subject and knowing how to teach it are two separate skills. Some experts are great teachers, but not simply by virtue of being experts. Recognizing that you have to approach teaching with humility, and that your expertise doesn’t automatically make you a skilled teacher, can go a long way toward making you a better teacher and mentor.
These aren’t easy and quick fixes to failures of metaknowledge. Both require ongoing intellectual humility and a willingness to distrust your own confidence. But acknowledging the fallibility of your own metaknowledge is a good place to start.
Thomas Blanchard does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
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