Five ways professional athletes are redefining the limits of age in sport

Source: The Conversation – UK – By Paul Hough, Lecturer Sport & Exercise Physiology , University of Westminster

Maciej Rogowski Photo/Shutterstock

In elite sport, the phrase “past your prime” is rapidly being redefined.

At 38, Jess Fishlock just became the oldest goalscorer in UEFA Women’s Euro history. At Euro 2024, Portuguese defender Pepe made headlines not for a red card or faking injury — but for simply stepping onto the pitch at age 41, becoming the oldest player to feature in a European Championship. Fellow veterans Cristiano Ronaldo (39), Luka Modrić (38), and Keylor Navas (38) also made appearances.

And it’s not just football. Serena Williams won the Australian Open at 35 (while pregnant). Roger Federer won a Grand Slam at 36. Rafael Nadal became the oldest French Open champion at 36. Novak Djokovic, now 38, won Olympic gold in 2024 and reached the semi-finals of all three Grand Slams this 2025.

In American sports, Tom Brady retired at 45 after 23 physically punishing NFL seasons. LeBron James, at 39, is still dominating in the NBA, having won the inaugural NBA Cup with the LA Lakers in 2023.

These aren’t just feel-good stories; they reflect a growing trend. Athletes are staying competitive for longer and pushing the boundaries of peak performance. But how?

Research backs the shift. A study on Olympic athletes found that between 1992 and 2021, the average age of male Olympians rose from 25 to 27, and female athletes from 24 to 26. In football, a study of UEFA Champions League players found the average player age rose by nearly two years between 1992 and 2018.

So how are older athletes continuing to thrive in elite sport? Here are some of the key factors.

1. Smarter training

Modern athletes benefit from personalised training programmes informed by cutting-edge sports science. Tools like GPS tracking, heart rate variability (HRV), and biomarker analysis help coaches monitor performance, recovery and injury risk.

Metrics such as HRV, for example, can indicate when an athlete might need more rest, which is crucial for older athletes who take longer to recover after intense competition.

Athletes are no longer reliant on a single coach. Today, they work with integrated teams – sports scientists, strength and conditioning coaches, and performance analysts – all dedicated to improving their fitness and performance.

2. Better injury prevention and medical support

Athletes now undergo regular fitness testing and musculoskeletal screening to identify potential weaknesses before they lead to injury. And when injuries do occur, recovery methods have vastly improved.

Anterior cruciate ligament (ACL) injuries were once considered career-ending for older athletes. But thanks to advanced surgical techniques and biological therapies, recovery is now faster, and athletes return to play much sooner.

Zlatan Ibrahimović, at age 35, returned to top-level football just seven months after an ACL tear – a feat nearly unthinkable a decade earlier.

3. Optimised recovery and nutrition

Ageing athletes have different recovery needs — and sports science has stepped up. Cryotherapy, compression therapy, and advanced sleep protocols all help reduce muscle soreness and accelerate repair.

Nutrition plays a key role too. Ageing bodies experience more inflammation and slower repair, so diets rich in polyphenols (found in berries, leafy greens, and dark chocolate) are used to support vascular health and recovery. Athletes may also take approved supplements such as glucosamine and chondroitin to support joint health and slow degeneration.

The result? Older athletes can train more consistently and recover faster between games.

4. Experience and tactical intelligence

Speed and strength decline with age, but tactical intelligence often improves. Older athletes can compensate for age-related declines in physical capacity with their advanced game-reading skills and spatial awareness. For instance, footballers like Paul Scholes and Andrés Iniesta adapted their playing styles with age, relying more on positioning and passing intelligence than physical capacity.

5. Financial and legacy incentives

Today’s stars aren’t just competing for medals – they’re building brands. With massive financial rewards on offer, there’s a clear incentive to prolong careers.

Cristiano Ronaldo, for example, recently signed a two-year contract extension with Al-Nassr that will see him play until age 42 — reportedly earning an estimated £492 million. For many athletes, the chance to leave a lasting legacy and secure generational wealth keeps them in the game.

While we can’t stop the biological effects of ageing, today’s athletes are proving we can delay their impact – and even thrive later in life.

With smarter training, better recovery strategies and cutting-edge medicine, the upper age limit for peak performance continues to stretch. These advances may allow more veteran athletes to defy expectations and continue competing at the highest level.


Get your news from actual experts, straight to your inbox. Sign up to our daily newsletter to receive all The Conversation UK’s latest coverage of news and research, from politics and business to the arts and sciences.

The Conversation

Paul Hough 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.

ref. Five ways professional athletes are redefining the limits of age in sport – https://theconversation.com/five-ways-professional-athletes-are-redefining-the-limits-of-age-in-sport-261028

Subsidising e-bikes instead of cars could really kick the electric vehicle transition into high gear

Source: The Conversation – UK – By Noel Flay Cass, Research Fellow in Energy Demand Behaviour, University of Leeds

If you’re thinking of buying a new electric car worth up to £37,000, the UK government has offered to knock up to £3,750 off the price. The measure adds up to £650 million in grants for people to buy EVs (electric vehicles), but as a researcher who studies transport policy and climate change, I think this money would be better spent subsidising e-bikes.

Numerous questions surround the new government policy. Might people who can afford a new car buy one anyway, without the 10% discount? Might car dealers simply reduce the discounts they offer by a similar amount? Given the 20% VAT on an EV, doesn’t a sale actually result in a 200% immediate return for the government? And isn’t this mainly a bung to car manufacturers and company fleets?

The grants come on top of financial assistance for replacing cars, vans, taxis and motorbikes with electric options, announced in February – £120 million in total, including £500 grants for e-motorbikes. But almost no subsidies are available for two-wheeled, pedal-assisted EVs: e-bikes and e-cargo bikes.

The main financial help for buying e-bikes is the cycle to work salary-sacrifice scheme. The employer buys the bike and then instalments are deducted from a participant’s pay before tax, but the scheme’s eligibility is limited to employees on standard payroll tax (PAYE workers) whose sacrifices don’t drop their pay below minimum wage.

This also excludes those who are out of work, the low-paid, the self-employed and retired, arguably people who might benefit most from an e-bike.

Benefits beyond carbon savings

We know that e-bike owners replace lots of trips and miles driven by cars. We also know the upfront cost of around £2,000-£3,000 is a barrier to more people owning one, despite e-bikes being much cheaper than cars.

Estimates of annual carbon savings from e-bikers avoiding car trips vary, from as little as 87kg CO₂ in a 2016 study to 394kg in research published the following year. Estimates published in 2020 and 2023 put the annual climate dividend at 225kg and 168kg of CO₂ respectively – roughly in line with emissions for one person making a return short-haul flight.

A senior woman on an e-bike surrounded in a park.
E-bikes provide extra propulsion to make long or arduous journeys easier for more riders.
Umomos/Shutterstock

These might seem small savings compared to the tonnes of CO₂ that an EV can save. However, e-bike incentives would have two big advantages.

First, policies that encourage active travel, including cycling, have been assessed by the government multiple times to determine the payoff from investment. It turns out that they have huge benefit to cost ratios – 9:1 on average (internationally it’s 6:1).

Conservatively, policies to encourage cycling pay back £5.50 in social benefits for every £1 invested. These benefits are largely savings for the healthcare system. In a project I worked on, in which we lent e-cargo bikes for free to 49 households in Leeds, Brighton and Oxford for several months, e-cargo bike users cycled up to three times more than non-users in our surveys.

E-cargo bike borrowers also reported mental-health benefits on top of satisfaction at being able to combine fitness with functional everyday trips, which were longer than they would attempt on a conventional bike. The cargo bikes especially helped with combining trips – commutes with shopping and school runs, for instance – meaning that more than 50% of trips and miles replaced car usage.

A woman riding a bike with a large cargo hold on the front which a child is sitting in.
Precious cargo.
R.Classen/Shutterstock

Second, e-bike incentives can be designed to appeal especially to the lower-paid, who have been found to use their e-bikes more than wealthier buyers, which would also replace more car trips. The highest of a sliding scale of means-tested incentives in a Canadian study attracted poorer first-time e-bike buyers with existing high car-use.

This reaped average annual carbon savings of 1,456kg for those in receipt of the maximum CAN$1,600 (£868). As the authors suggest, these incentives may have helped low-income households realise their preferences for less dependence on cars.

E-bike grants could get more people out of cars

But how many drivers want to drive less? According to research that groups people into camps based on travel preferences, up to 50% of travellers in the UK are “malcontented motorists” and “active aspirers” (to travel differently).

A man in a suit and helmet attending his e-bike.
Research has shown great potential for wider e-bike ridership.
Halfpoint/Shutterstock

Our research also found that guilt, or trying to minimise car use, was a major motivator for nearly all of our participants. While the government has funded free e-(cargo) bike trials like ours, the main cycling organisations we talked to pointed out that use would “fall off a cliff” when the trial ends because of the cost barrier. Those who would struggle to buy one were back in the same position as before.

A government evaluation of free e-bike loans concluded they were poor value for money, but it tracked purchases made soon after with a tiny response rate. Our project followed up after a year and found 20% of our borrowers had bought an e-cargo bike. Trial loans and grants together might achieve even more.

The new EV grant money could provide nearly 750,000 e-bike or e-cargo bike purchase-incentives the size of the Canadian ones, which could lead to annual carbon savings of 1.125 million tonnes of CO₂, according to the weekly average savings they found in that group.

Given the conservative benefit to cost ratio of 5.5:1 from such a UK scheme, this investment could also reap more than £3.6 billion in social benefits – especially from a fitter car-dependent population. There would potentially be a massive boost to the struggling UK e-bike and e-cargo bike market as well.


Don’t have time to read about climate change as much as you’d like?

Get a weekly roundup in your inbox instead. Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. Join the 45,000+ readers who’ve subscribed so far.


The Conversation

Noel Flay Cass receives funding from UK Research & Innovation grant EP/S030700/1 through the Elevate project: (Innovative Light ELEctric Vehicles for Active and Digital TravEl).

ref. Subsidising e-bikes instead of cars could really kick the electric vehicle transition into high gear – https://theconversation.com/subsidising-e-bikes-instead-of-cars-could-really-kick-the-electric-vehicle-transition-into-high-gear-261429

Canadian wetlands are treasures that deserve protection

Source: The Conversation – Canada – By Maria Strack, Professor, Department of Geography and Environmental Management, University of Waterloo

The Grande Plée Bleue bog, near Québec City in June 2023. This peatland with pools is one of the largest wetlands in eastern Québec. (Maria Strack)

Though Canada is often known as a land of lakes, it is also a country of wetlands. Stretching like a necklace of emeralds, sapphires and rubies across the Canadian landscape, wetlands cover 14 per cent of the Canadian land mass, accounting for almost twice as much area as lakes.

Canada is home to a quarter of the world’s remaining wetlands, yet they remain like hidden treasures that most Canadians rarely pay a second thought.

The importance of wetlands to a sustainable future has been recognized internationally. Signed in 1971 in the Iranian city of Ramsar, the Convention on Wetlands — often called the Ramsar Convention — supports international collaboration and national action for the conservation of wetlands.

This week, delegations from contracting parties to the convention, including Canada, have come together in Victoria Falls, Zimbabwe, for the 15th Conference of the Parties.

Despite decades of efforts, wetlands continue to be under threat around the world. Delegates will work this week to chart a path forward that further elevates wetlands in the global consciousness, highlighting the need to protect these ecosystems and meet international goals to safeguard biodiversity and slow climate warming.

Canada currently has 37 Wetlands of International Importance under the Ramsar Convention, covering more than 13 million hectares. Yet many of Canada’s wetlands remain unprotected.

Canada’s wetlands

The term “wetland” usually conjures an image of a shallow pond bordered by cattails. In fact, Canadian wetlands come in a range of shapes and sizes, all of which provide valuable services. Those reedy marshes provide critically important habitat and water storage, particularly in the Prairies, southern Ontario and Québec.

The vast majority of Canada’s wetlands are made up of swamps, fens and bogs, most of which also hold deep deposits of organic soils called peat. Bogs and fens can resemble vast mossy carpets. But they can also look a lot like forests, hiding their soggy soils beneath a canopy of trees.

This wetland diversity contributes to their value. At the interface of terrestrial and aquatic ecosystems, wetlands are often biodiversity hotspots.

They are home to weird and wonderful species, including carnivorous plants like sundews, pitcher plants and bladderworts. And if you’re hungry, peatlands are a great place for berry picking.

Interwoven in our boreal landscape, wetlands also support iconic Canadian species like beavers, moose and woodland caribou and are key habitats for waterfowl and other migratory birds.

Preserving wetlands is also a key flood mitigation strategy. Storm water can fill up pore spaces in mossy peat soils, or spread out across the flat expanse of swamps and marshes, reducing peak flows and helping to protect downstream infrastructure. As the water slows, water quality can also be improved. Sediments have time to settle, while plants and microbes can remove excess nutrients.

Carbon storage

In recent decades, wetlands have gained international attention for their role in carbon storage. Waterlogged sediment and soil lead to slow rates of decomposition. When plant litter falls in a wetland, it builds up over time, creating a bank of carbon that can be stored for millennia.

Peatlands are particularly good at accumulating carbon, as they are home to plants that inherently decompose slowly. Because of this, peatlands store twice the carbon of the world’s forests. Keeping this carbon stored in wetland soils, and out of the atmosphere, is important to climate change mitigation.

Yet, the buildup of carbon in wetlands is slow. Many of these ecosystems have been adding to this carbon bank since the last ice age; digging through metres of peat is like travelling back through time, with the deposits at the bottom often thousands of years old.

This means that the carbon stored in wetlands is irrecoverable within human lifetimes. Once lost, it will be many generations before the full value of this treasure can be returned.

The economic value of the water-filtering and carbon storage that Canadian wetlands provide has been estimated at $225 billion per year. It’s clear: healthy wetlands contribute to our society’s well-being.

But just as important, they are an integral component of the Canadian landscape. Wetlands are interwoven with our forests, fields, lakes and now even our cities. They link us to the land and water. They are places of wonder and spiritual connection.

Impact of climate change

Despite their value, wetlands in Canada face many threats. In southern regions of Canada, most wetlands have already been lost to drainage for agriculture and urban development. Further north, up to 98 per cent of Canadian peatlands remain intact.

However, climate change and resource development are already exacerbating wetland disturbance and loss. Warming temperatures have contributed to larger and more severe wildfire that also impact peatlands and lead to large carbon emissions.

Thawing permafrost is further changing wetland landscapes and how they function. Warming also allows for northward expansion of agriculture with the potential for loss of even more wetland area to drainage.

Natural resource extraction further contributes to wetland disturbance, often with unexpected consequences. Geologic exploration used to map oil and gas reserves has left a network of over one million kilometres of linear forest clearing across the boreal forest, much of which crosses peatlands.




Read more:
How climate change is impacting the Hudson Bay Lowlands — Canada’s largest wetland


This has contributed to declines in woodland caribou populations and led to increases in methane emissions from these ecosystems.

Mining often involves regional drainage or excavation of peatlands, resulting in the loss of their services. The recent push to fast-track production of critical minerals in Canada is putting vast areas of our wetlands at risk.

Wetland restoration research is ongoing, with some promising results. However, given the long time-scale of wetland development, avoiding disturbances in the first place is the best way to safeguard wetlands.

As stewards of a quarter of world’s wetland treasures, policymakers and everyday Canadians need to ensure wetlands are safeguarded and preserved for a prosperous future.

The Conversation

Maria Strack receives funding from the Natural Sciences and Engineering Research Council of Canada, Environment and Climate Change Canada, the Canadian Sphagnum Peat Moss Association, Ducks Unlimited Canada, Imperial Oil Ltd., Alberta Pacific Forest Industries Inc., Cenovus Energy, Canadian Natural Resources Limited, ConocoPhillips Canada, Natural Resources Canada, and the Alberta Biodiversity Monitoring Institute.

ref. Canadian wetlands are treasures that deserve protection – https://theconversation.com/canadian-wetlands-are-treasures-that-deserve-protection-261433

Togo’s ‘Nana-Benz’: how cheap Chinese imports of African fabrics has hurt the famous women traders

Source: The Conversation – Africa – By Fidele B. Ebia, Postdoctoral fellow, Duke Africa Initiative, Duke University

The manufacturing of African print textiles has shifted to China in the 21st century. While they are widely consumed in African countries – and symbolic of the continent – the rise of “made in China” has undermined the African women traders who have long shaped the retail and distribution of this cloth.

For many decades Vlisco, the Dutch textile group which traces its origins to 1846 and whose products had been supplied to west Africa by European trading houses since the late 19th century, dominated manufacture of the cloth. But in the last 25 years dozens of factories in China have begun to supply African print textiles to west African markets. Qingdao Phoenix Hitarget Ltd, Sanhe Linqing Textile Group and Waxhaux Ltd are among the best known.

We conducted research to establish how the rise of Chinese-made cloth has affected the African print textiles trade. We focused on Togo. Though it’s a tiny country with a population of only 9.7 million, the capital city, Lomé, is the trading hub in west Africa for the textiles.

We conducted over 100 interviews with traders, street sellers, port agents or brokers, government officials and representatives of manufacturing companies to learn about how their activities have changed.

“Made in China” African print textiles are substantially cheaper and more accessible to a wider population than Vlisco fabric. Our market observations in Lomé’s famous Assigamé market found that Chinese African print textiles cost about 9,000 CFA (US$16) for six yards – one complete outfit. Wax Hollandais (50,000 CFA or US$87) cost over five times more.

Data is hard to come by, but our estimates suggest that 90% of imports of these textiles to Lomé port in 2019 came from China.

One Togolese trader summed up the attraction:

Who could resist a cloth that looked similar, but that cost much less than real Vlisco?

Our research shows how the rise of China manufactured cloth has undermined Vlisco’s once dominant market share as well as the monopoly on the trade of Dutch African print textiles that Togolese traders once enjoyed.

The traders, known as Nana-Benz because of the expensive cars they drove, once enjoyed an economic and political significance disproportionate to their small numbers. Their political influence was such that they were key backers of Togo’s first president, Sylvanus Olympio – himself a former director of the United Africa Company, which distributed Dutch cloth.

In turn, Olympio and long-term leader General Gnassingbé Eyadéma provided policy favours – such as low taxes – to support trading activity. In the 1970s, African print textile trade was considered as significant as the phosphate industry – the country’s primary export.

Nana-Benz have since been displaced – their numbers falling from 50 to about 20. Newer Togolese traders – known as Nanettes or “little Nanas” – have taken their place. While they have carved out a niche in mediating the textiles trade with China, they have lower economic and political stature. In turn, they too are increasingly threatened by Chinese competition, more recently within trading and distribution as well.

China displaces the Dutch

Dating back to the colonial period, African women traders have played essential roles in the wholesale and distribution of Dutch cloth in west African markets. As many countries in the region attained independence from the 1950s onwards, Grand Marché – or Assigamé – in Lomé became the hub for African print textile trade.

While neighbouring countries such as Ghana limited imports as part of efforts to promote domestic industrialisation, Togolese traders secured favourable conditions. These included low taxes and use of the port.

Togolese women traders knew the taste of predominantly female, west African customers better than their mostly male, Dutch designers. The Nana-Benz were brought into the African print textile production and design process, selecting patterns and giving names to designs they knew would sell.

They acquired such wealth from this trade that they earned the Nana-Benz nickname from the cars they purchased and which they used to collect and move merchandise.

Nana-Benz exclusivity of trading and retailing of African print textiles cloth in west African markets has been disrupted. As Vlisco has responded to falling revenues – over 30% in the first five years of the 21st century – due to its Chinese competition, Togolese traders’ role in the supply chain of Dutch cloth has been downgraded.

In response to the flood of Chinese imports, the Dutch manufacturer re-positioned itself as a luxury fashion brand and placed greater focus on the marketing and distribution of the textiles.

Vlisco has opened several boutique stores in west and central Africa, starting with Cotonou (2008), Lomé (2008) and Abidjan (2009). The surviving Nana-Benz – an estimated 20 of the original 50 – operate under contract as retailers rather than traders and must follow strict rules of sale and pricing.

While newer Togolese traders known as Nanettes are involved in the sourcing of textiles from China, they have lower economic and political stature. Up to 60 are involved in the trade.

Former street sellers of textiles and other petty commodities, Nanettes began travelling to China in the early to mid-2000s to source African print textiles. They are involved in commissioning and advising on the manufacturing of African print textiles in China and the distribution in Africa.

While many Nanettes order the common Chinese brands, some own and market their own. These include what are now well-known designs in Lomé and west Africa such as “Femme de Caractère”, “Binta”, “Prestige”, “Rebecca Wax”, “GMG” and “Homeland”.

Compared to their Nana-Benz predecessors, the Nanettes carve out their business from the smaller pie available from the sale of cheaper Chinese cloth. Though the volumes traded are large, the margins are smaller due to the much lower final retail price compared to Dutch cloth.

After procuring African print textiles from China, Nanettes sell wholesale to independent local traders or “sellers” as well as traders from neighbouring countries. These sellers in turn break down the bulk they have purchased and sell it in smaller quantities to independent street vendors.

All African print textiles from China arrive in west Africa as an incomplete product – as six-yard or 12-yard segments of cloth, not as finished garments. Local tailors and seamstresses then make clothes according to consumer taste. Some fashion designers have also opened shops where they sell prêt-à-porter (ready-to-wear) garments made from bolts of African print and tailored to local taste. Thus, even though the monopoly of the Nana-Benz has been eroded, value is still added and captured locally.

Since the COVID-19 pandemic, Chinese actors have become more involved in trading activity – and not just manufacturing. The further evolution of Chinese presence risks an even greater marginalisation of locals, already excluded from manufacturing, from the trading and distribution end of the value chain. Maintaining their role – tailoring products to local culture and trends and linking the formal and informal economy – is vital not just for Togolese traders, but also the wider economy.

The Conversation

Rory Horner receives funding from the British Academy Mid-Career Fellowship. He is also a Research Associate at the Department of Geography, Environmental Management and Energy Studies at the University of Johannesburg.

Fidele B. Ebia 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.

ref. Togo’s ‘Nana-Benz’: how cheap Chinese imports of African fabrics has hurt the famous women traders – https://theconversation.com/togos-nana-benz-how-cheap-chinese-imports-of-african-fabrics-has-hurt-the-famous-women-traders-260924

AI chatbots can boost public health in Africa – why language inclusion matters

Source: The Conversation – Africa (2) – By Songbo Hu, PhD Candidate, University of Cambridge

Language technologies like generative artificial intelligence (AI) hold significant potential for public health. From outbreak detection systems that scan global news in real time, to chatbots providing mental health support and conversational diagnostic tools improving access to primary care, these innovations are helping address health challenges.

At the heart of these developments is natural language processing, an interdisciplinary field within AI research. It enables computers to interpret, understand and generate human language, bridging the gap between humans and machines. Natural language processing can process and analyse enormous volumes of health data, far more than humans could ever handle manually. This is especially valuable in regions with a stretched healthcare workforce or limited public health surveillance infrastructure, because it enables faster, data-driven responses to public health needs.

Recently, our interdisciplinary team, combining expertise from computer science, human geography and health sciences, conducted a review of studies on how language AI is being used for public health in African countries. Almost a decade’s worth of academic research was analysed, to understand how this powerful technology is being applied to pressing human needs.

Out of 54 research publications, we found that evidence of real-world effects of the technology was still rare. Only 4% of these studies (two out of 54) showed measurable improvements in public health, such as boosting people’s mood or increasing vaccine intentions.

Most projects stop at technology development and publication. Very few advance to real-world use or impact. Opportunities to improve health and well-being across the continent could be missed as a result.

Current limitations

In recent years, AI language technologies for public health have increased rapidly. This wave of technology development really took off as the COVID-19 pandemic renewed attention to public health. Health chatbots and sentiment analysis tools were developed in Africa and beyond.

Health chatbots “talk” to people and provide reliable health information in a friendly, conversational way. Sentiment analysis tools scan social media posts to understand what people are feeling and talking about. Together they can identify misinformation or changes in public opinion and then provide accurate information.

Of course, new technologies come with imperfections. We found that most technologies for public health in Africa exist in just a few languages whose dominance can be traced to colonial times, namely English and French.

The consequences are clear: key health messages fail to reach many communities, leaving millions unable to access or act on essential information.

We also found that few projects have gone beyond the laboratory development stage. Our study found only one system in operation that had a measurable public health effect.

A successful model

This standout example comes from a team at the Center for Global Development and the University of Chicago, in partnership with the Busara Center for Behavioral Economics. Their chatbot, deployed on Facebook Messenger, was designed for people in Kenya and Nigeria who were hesitant about COVID-19 vaccines. It was only available in English.

More than 22,000 social media users used this app, sharing vaccine-related questions and concerns. The chatbot provided tailored, evidence-based responses to topics ranging from vaccine effectiveness and safety to misinformation. Its effect was notable. The intervention boosted users’ intention and willingness to get vaccinated by 4%-5%. The strongest effects were seen among those most hesitant to begin with.

Behind this success was the researchers’ commitment to understanding the local context. Before launching the chatbot, in-depth discussions were held with focus groups and social media users in Kenya and Nigeria. The aim was to learn about the specific worries and cultural factors shaping attitudes toward vaccination.

The chatbot was designed to address these concerns. This user-centred, locally adapted approach enabled the chatbot’s messages to address real barriers. As this example demonstrates, language technologies for public health are most effective when responding to the concerns and needs of the intended users.

From lab to life

These technologies take time and money to be put into practice. The COVID-19 pandemic jump-started development but public health language AI technologies are very new. It could be that a future survey would find a very different situation.

At the same time, advances in large language models such as GPT-4 are rapidly lowering the technical barriers to developing language technologies. These models can often be adapted to new applications with far less data and effort than previous methods. Recent advances could enable small teams of researchers or even individual developers to build tools tailored to the specific needs of their own communities. The path from lab to real-world effects may become much shorter and easier.

Investors, accelerators and state support could help make this transition from lab to life happen.

Technology developers can also contribute by rooting their work in community-driven, multi-disciplinary and cross-sector collaboration. Social science and public health research knowledge and skills can inform the design and development of new technologies.

To maximise the potential of language technologies for public health, the following needs to happen:

  • involving communities and health workers in natural language processing design

  • expanding provision in indigenous African languages

  • integrating language technologies into existing health systems.

Future research and development must move beyond technical prototypes and laboratory tests to rigorous real-world evaluations that measure health outcomes.

The other co-authors behind this research are: Abigail Oppong, Ebele Mogo, Charlotte Collins, and Giulia Occhini.

The Conversation

Songbo Hu currently receives funding from the Cambridge Trust.

Anna Barford currently receives funding from UKRI and the Mastercard Foundation. She has previously received funding from the the British Aacdemy, ESRC, Leverhulme Trust, CPEST, the University of Cambridge, Unilever (via a philanthropic donation to the University) and the Asian Development Bank. Anna is the Co-Director of the Business Fights Poverty Institute and a consultant to the International Labour Organization.

Anna Korhonen receives funding from UKRI, and has previously received funding from MRC, EPSRC, NERC, Royal Society, ERC, and philantrophic donations to the University of Cambridge.

ref. AI chatbots can boost public health in Africa – why language inclusion matters – https://theconversation.com/ai-chatbots-can-boost-public-health-in-africa-why-language-inclusion-matters-260861

Five reasons why driverless cars probably won’t take over your street any time soon

Source: The Conversation – UK – By Seyed Toliyat, Lecturer in Business Analytics and Technology, University of Stirling

Karolis Kavolelis/Shutterstock

The UK government has launched a consultation on driverless cars, ahead of on-the-road trials of the vehicles next year. It has now been more than a decade since the prospect of driverless cars on public roads emerged, and prototypes and robotaxi fleets such as Waymo and Cruise replaced human drivers with artificial intelligence (AI).

But ten years on, and with self-driving cars increasingly common in the US and China, significant obstacles still stand in their way in the UK.

Despite rapid advances in the tech, other aspects of the driverless journey are still to catch up. Here are five key reasons why autonomous cars are unlikely to take over your local roads any time soon.

1. Uncertainties around safety

One of the main benefits of rolling out driverless cars is to increase traffic safety by eliminating driver errors. In the US, the National Highway Traffic Safety Administration reported in 2018 that more than 90% of serious crashes were due to human error. But there is not yet converging evidence to support the idea that AI taking over from human drivers can make roads safer.

On the other hand, there is evidence that adverse weather conditions, road design, traffic control systems and mixed traffic (that is, human-driven and driverless cars) can degrade the performance of those vehicles. Anomalies in driving patterns and frequent rear-end crashes involving self-driving technologies could indicate the AI algorithms are still far from perfect.

2. Regulations and legislation falling behind

Substantial investment in research and development of self-driving technologies has led to a fast-growing and innovative industry. On the other hand, legislation and regulation processes often tend to be slower. These involve multiple stages including drafting, consultation, debate, committee reviews, voting and sometimes judicial review.

The UK’s Automated Vehicles Act provides a framework for the deployment of driverless vehicles. But the legal codes and mechanisms are still evolving. This is also true of data privacy and cybersecurity.

For now, there is insufficient legislation governing who can own telematics and vehicle data or how they can be used. Such a widening lag has implications for the mass rollout of driverless cars, and has a direct impact on insuring them.

3. The insurance industry isn’t ready

Scarce data, combined with ambiguities in legislation and regulations, means insurance companies face a new set of challenges. These include making sense of where liability lies, developing new insurance models and adapting their premiums as the types of claim evolve.

In some countries, including the UK, the liability for levels four and five of autonomous driving (very highly automated and fully automated) is shifting from human drivers in conventional vehicles to the manufacturer. Although the insurer pays first, they can recover costs from the tech provider later.

New risk factors such as cybersecurity further complicate the insurance landscape. Driverless cars are designed to communicate with infrastructure and even other vehicles to decide their routes and avoid collisions. This can open the door to unlawful modifications, hacking or privacy breaches.

4. Ethical dilemmas

Heavy traffic and the presence of other road users could lead to scenarios where a crash is inevitable. This would require programmers to design crash severity algorithms that include moral decision-making into autonomous systems. In simple terms, programmers are effectively being asked to write codes that assign value to human lives – an ethical minefield that has yet to be resolved in either academia or industry.

This echoes the “trolley problem” (a thought experiment about killing one person to save others) but with real-world legal and moral significance. It poses further legal and regulatory questions that could further slow the progress of legislation. Complicating things further is the opaque, black-box nature of AI algorithms.

5. Changing business models

Technology developers such as Waymo and Zoox offer only driverless rides and don’t sell vehicles. The recent move by Tesla to launch a robotaxi service in Austin, Texas, also indicates a shift from selling cars to “mobility as a service”, even by car manufacturers.

In some societies like the US, there is resistance among consumers to relinquishing car ownership due to higher car dependency. This mismatch between the business models of the makers of driverless cars and consumer preferences presents another significant barrier to widespread adoption.

Even if the technical obstacles are removed, these deeply held sentiments about the nature of mobility may prevent consumers abandoning private vehicles.

Until the technical, legal, ethical and commercial challenges are addressed, the widespread rollout of driverless vehicles will remain more of a long-term vision than an immediate reality.


Get your news from actual experts, straight to your inbox. Sign up to our daily newsletter to receive all The Conversation UK’s latest coverage of news and research, from politics and business to the arts and sciences.

The Conversation

Seyed Toliyat 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.

ref. Five reasons why driverless cars probably won’t take over your street any time soon – https://theconversation.com/five-reasons-why-driverless-cars-probably-wont-take-over-your-street-any-time-soon-261040

Congress has a chequered history of overseeing US intelligence and national security

Source: The Conversation – UK – By Luca Trenta, Associate Professor in International Relations, Swansea University

Tonya Ugoretz, a top FBI intelligence analyst, was placed on administrative leave in June. The FBI has not said why. But the decision came around the time she refused to endorse what was reportedly a thinly sourced report accusing China of interfering in the 2020 US presidential election in favour of Joe Biden.

At the Bureau, loyalty tests and polygraph checks have also allegedly become routine as part of a crackdown on news leaks. When approached by the New York Times about the matter, the FBI declined to comment and cited “personnel matters and internal deliberations”.

The situation does not seem to be much different at the CIA. In May, agency director John Ratcliffe ordered a review of the intelligence community’s earlier conclusion that Russia had interfered in the 2016 presidential campaign on behalf of Donald Trump. The conclusion, Ratcliffe contends, was unwarranted and imposed by political pressure – a claim that has been rejected by one of the report’s leading authors.

The intelligence community has reportedly also been under pressure to substantiate Trump’s claims that the recent military strikes on Iran had obliterated its nuclear sites. This is despite mixed evidence regarding the extent of their success. These examples suggest a growing politicisation of intelligence and national security in the US.

Researchers and observers have highlighted the detrimental effect of this process. When intelligence is conducted by ideologues that are screened for loyalty, it often becomes more about pleasing the leader than collecting accurate information and preventing failure.

Less attention has been paid to the permissive attitude of Congress. Many Republicans in Congress have taken an unquestioning attitude toward the claims made by the president and other officials, allowing intelligence agencies to pursue Trump’s agenda unimpeded.

While Trump and Patel’s focus on personal loyalty when it comes to intelligence is new, partisan influence in congressional oversight is not. In fact, Congress has a long history of supporting the intelligence priorities of the governing administration.

For much of the cold war, Congress was not involved – and did not want to be involved – in matters of intelligence. This view was expressed by former CIA legal counsel, Walter Pforzheimer, during an interview in 1988. Reflecting on the early days of oversight, he stated: “It wasn’t that we were attempting to hide anything. Our main problem was we couldn’t get them [Congress] to sit still and listen.”

This quote isn’t entirely true. In research from 2023, I showed that Congress was more involved than was generally believed. The US-backed 1954 coup in Guatemala, which deposed the democratically elected president, Jacobo Árbenz, is a case in point. Leading members of Congress were “in the know” and others pushed Dwight Eisenhower’s administration to be even more aggressive.

But Congress took on a more active role in intelligence matters in the 1970s. Following a series of public revelations about the CIA’s behaviour, a select committee was established in 1975 and exposed abuses by intelligence agencies including the surveillance of US citizens, experiments with drugs and involvement in assassinations.

In the wake of this, Congress established intelligence committees with oversight duties. The idea was that the CIA would present a document signed by the president to notify congressional committees of its intentions.

However, the system ran into trouble in the 1980s, and partisanship and politicisation were part of the story. The Ronald Reagan administration’s support for the “contra” rebels in Nicaragua made intelligence a matter of severe partisan conflict.

Removing Nicaragua’s government

When Reagan took office in 1981, one of the primary foreign policy priorities for his administration was removing the Sandinista National Liberation Front from power in Nicaragua. The administration saw the Sandinistas as a threat to the region and – in Reagan’s black-and-white thinking – as puppets of Communist Moscow and Havana.

The administration sought to convince Congress that its aims were limited. The aim, or so CIA director William Casey told the intelligence committees, was to obstruct the transfer of weapons from Nicaragua to neighbouring El Salvador. Another left-wing guerrilla movement, the Farabundo Martí National Liberation Front, was threatening the US-supported government there.

Initially, the policy received bipartisan support in Congress. The linchpin of this policy was the creation of an insurgent group in Nicaragua called the contras (contrarevolucionarios). It was made up of members of the previous regime’s brutal national guard, as well as other groups that had become disgruntled with the Sandinistas.

A group of Nicaraguan contras
Nicaraguan contras, who fought against the Sandinista government in Nicaragua during the 1980s.
Tiomono / Wikimedia Commons, CC BY-NC-SA

News stories soon made clear that the size of the contra army had radically expanded, from the 500 members discussed by Casey in his initial briefing to thousands. The contras’ stated goal of overthrowing the Sandinistas, which they ultimately failed to do, also contradicted the earlier Reagan administration’s statements to Congress.

Democrats in Congress pushed the leadership of intelligence committees to curtail the administration’s activities. Edward Boland, chairman of the House Intelligence Committee, penned and helped to pass two amendments. The first prohibited any US government support for the purpose of overthrowing the Nicaraguan government.

When the administration found loopholes to circumvent this, Boland’s second amendment prohibited any US funds from being spent in support of the contras. This amendment is generally understood as a first step towards the so-called Iran-Contra scandal.

The Reagan administration illegally funded the contras behind Congress’s back by using the proceeds from secret arms sales to Iran – a state the US had been at loggerheads with since the 1979 Islamic revolution.

The Boland amendments also helped make an intelligence and covert operations issue a matter of public debate and – more importantly – congressional votes. Republicans in Congress abandoned their oversight duties and followed the administration’s guidelines.

Votes on contra aid became an opportunity for partisan controversy, vitriolic attacks, accusations of betrayal and large-scale influence campaigns. Instead of oversight, a deep partisan divide materialised.

Counting on Congress? Think again

The role of Congress is to conduct oversight. It is the role of the governing administration to keep Congress informed of intelligence matters, particularly covert operations. History shows this has often been hard to achieve.

Congress has been complacent, complicit and often too willing to follow the government’s lead. In some cases, Congress has acted but primarily in the aftermath of major scandals or media revelations. This is called “firefighting” behaviour.

But “firefighters” seem to now be in short supply. As much as domestic constraints on Trump’s power are decreasing, the same is happening in the context of intelligence and foreign policy.


Get your news from actual experts, straight to your inbox. Sign up to our daily newsletter to receive all The Conversation UK’s latest coverage of news and research, from politics and business to the arts and sciences.

The Conversation

Luca Trenta received funding from British Academy Grant SRG21211237.

ref. Congress has a chequered history of overseeing US intelligence and national security – https://theconversation.com/congress-has-a-chequered-history-of-overseeing-us-intelligence-and-national-security-261120

Grandparent care: women from poorer backgrounds help out most with childcare

Source: The Conversation – UK – By Giorgio Di Gessa, Lecturer in Data Science, UCL

szefei/Shutterstock

Grandparents play a pivotal role in family life. They are often a vital part of the childcare puzzle, stepping in to look after their grandchildren while parents are at work or busy. And there’s a lot of grandparent care taking place.

In England, around half of all grandparents provide care for their grandchildren when the parents are not around. And the percentage of grandparents providing care is even higher when they have grandchildren aged 16 and under, who are more likely to require supervision, care, and support from an adult when the parents are busy at work or unavailable. In this case, 66% of grandparents help out.

I used data from the English Longitudinal Study of Ageing, to analyse the caring roles of over 5,000 grandparents. I used data collected in 2016-17 to assess how often grandparents looked after their grandchildren, the activities they did with them, and why they helped out. I also discovered that there are clear gender and socioeconomic patterns. Further analysis of data from 2018-19 showed that providing care as a grandparent can affect wellbeing.

I found that in England, among grandparents who looked after grandchildren, 45% of grandparents spent at least one day a week looking after their young grandchildren. They did so consistently throughout the year, with 8% doing so almost daily. Approximately one in three grandparents provided care to their grandchildren during school holidays.

Around 25% of grandparents who looked after their grandchildren were still working. Most grandparents reported having overall good physical health.

And most grandparents who cared for their grandchildren also lived relatively close to them – less than half an hour away from their closest grandchild – and had at least one grandchild aged under six years old.

Most of the grandparents in the study who cared for grandchildren – 80% – mentioned that they played or took part in leisure activities with their grandchildren. Around half said that they frequently cooked for them and helped with picking them up and dropping them off from schools and nurseries. And although it was less common, grandparents also helped with homework and taking care of their grandchildren when they were not feeling well.

About three grandparents in four (76%) said that their motivation for helping out was to give their grandchildren’s parents some time out from childcare responsibilities. A similar percentage – 70% – said they wanted to provide some economic support, either by offering financial assistance or by allowing parents to go to work.

Just over half of grandparents (52%) said that being able to provide emotional support was what drove their motivation to provide grandchild care: they wanted to feel engaged with young people and help their grandchildren develop. But 17% say that they felt obliged to help out, and found it difficult to refuse.

The grandmother’s role

But while we tend to talk about “grandparents” as a group, grandmothers and grandfathers often experience and approach caregiving in distinctly different ways.

In particular, when examining the specific activities undertaken with their grandchildren, there are clear gender distinctions. I found that grandmothers were more likely than grandfathers to engage in hands-on tasks: preparing meals, helping with homework, caring for grandchildren when they are sick, and doing school pick-ups.

Grandfather reading book with child
Grandfathers were less likely to do hands-on caring activities, such as school pickups.
Rawpixel.com/Shutterstock

Grandfathers, while also involved, tended to participate less in these activities. This is the case even among grandparent couples who lived together and jointly cared for their grandchildren.

The role of wealth

The extent and nature of grandparental care is also closely linked to grandparents’ socioeconomic status. For example, grandparents with fewer financial resources tended to offer childcare more regularly than their wealthier counterparts.

Socioeconomic disparities also shape the nature of caregiving tasks. Less affluent grandparents were more likely to engage in hands-on activities, such as cooking meals and taking their grandchildren to and from school. In contrast, grandparents with more education were more likely than those with less education to help with homework frequently.

The reasons for providing care also varied according to grandparents’ socioeconomic status. Grandparents with greater financial resources and higher levels of education were more likely to report providing childcare to help parents manage work and other responsibilities, as well as to offer emotional support to their grandchildren. Conversely, those with fewer financial resources were more likely to feel obliged to help or to struggle to refuse caregiving duties.

Grandparent wellbeing

What grandparents do with their grandchildren and why they have an active role in caring for them can also affect their wellbeing in complex ways. Grandparents who often took part in fun or enriching activities with their grandchildren, such as leisure activities or helping with homework, tended to report higher wellbeing compared to their peers who did not look after grandchildren.

However, grandparents who cared for their grandchildren when they were sick or who had them stay overnight without parents tended to report, over time, lower wellbeing.

Motivations also matter for grandparents’ wellbeing. Grandparents had a higher quality of life if they cared for their grandchildren because they wanted to help them develop as people, or to feel engaged with young people. However, grandparents who felt obliged to help, perhaps due to family pressure or lack of alternatives, experienced lower wellbeing.

In short, these findings remind us that behind the broad label of “grandparenting” lies a diverse world of individuals whose involvement in caring for grandchildren – how often they care, what they do, and why – is closely linked to and varies with gender norms and socioeconomic status.

Also, the meaning behind grandparenting and the type of interactions shared with grandchildren seems to matter for grandparents’ wellbeing. Overall, these insights suggest that these caring responsibilities may contribute to the reinforcement or even deepening of existing gender, socioeconomic and health inequalities among older adults.


Get your news from actual experts, straight to your inbox. Sign up to our daily newsletter to receive all The Conversation UK’s latest coverage of news and research, from politics and business to the arts and sciences.

The Conversation

Giorgio Di Gessa 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.

ref. Grandparent care: women from poorer backgrounds help out most with childcare – https://theconversation.com/grandparent-care-women-from-poorer-backgrounds-help-out-most-with-childcare-253168

Physically restricting mental health patients can often harm them – my new study suggests compassion could change that

Source: The Conversation – UK – By Daniel Lawrence, Senior Lecturer in Forensic Psychology, Cardiff Metropolitan University

Restrictive practices in mental health settings – such as physical restraint and seclusion – are meant to be a last resort, used only when patients pose a risk to themselves or others.

In 2021 and 2022 alone, NHS England reported that 6,600 mental health patients were subjected to physical restraint, and 4,500 to seclusion. Figures such as these have led numerous experts and policymakers to conclude that restrictive practices are overused in mental health inpatient settings.

The consequences can be devastating. Restrictive practices are associated with trauma, worsening mental health, and even death. For decades, clinicians, researchers and policymakers have called for their reduction. Progress, however, remains painfully slow.

For the past five years, I have been researching the use of restrictive practices in mental health services and exploring how to reduce them. My new research demonstrates the importance of using compassion to support staff to promote the dignity and wellbeing of patients as a priority.

Restrictive practices have a long history that predates the development of asylums and psychiatry as a medical discipline. The use of legislation to detain people on the basis of their mental health in England, for example, dates back to at least the 14th century. Early examples of restrictive practices included patients being bound and beaten with rods in order to “restore sanity”.

During the first three decades of the 19th century, mechanical restraints such as straitjackets, chains and restraint chairs and confining patients in locked rooms were widely accepted methods of controlling violent people in British asylums. But in the 1830s, some clinicians recognised the moral and ethical problems with using such practices, and a campaign began to abolish them.

The UN has long recognised restrictive practices in mental healthcare as a human rights issue. In 2008, the UN’s special rapporteur on torture stated that methods such as solitary confinement violate articles 14 and 15 of the Convention on the Rights of Persons with Disabilities, which protect against arbitrary detention and cruel, inhuman or degrading treatment.

This stance was reaffirmed in 2021 when the UN declared that restrictive practices breach the fundamental rights of patients. This underscores the urgent need for reform in mental healthcare systems worldwide.

Harmful effect

Research shows that restrictive practices may not only harm patients but contradict the goals of mental healthcare. Many mental health problems stem from traumatic experiences that leave people feeling powerless, unsafe and distressed. Using methods that reinforce these feelings can worsen the very issues services aim to address.

In extreme incidents, people have died as a result of restrictive practices use.

In my research, I have developed a theoretical model identifying core factors that perpetuate the use of restrictive practices in mental health services. These include the emotional challenges faced by staff working in high-stress environments, and how these challenges influence their decision-making.

Mental health wards can be highly stressful environments, with frequent incidents of aggression. In such settings, staff can often feel anxious and hyper-vigilant, which can make it harder for them to respond to patients with compassion.

Research shows that threat-based emotions like fear and anger are linked to a greater likelihood of using restrictive measures. So, this cycle perpetuates the use of these harmful practices.

Compassion may hold the key

Using restrictive practices to control or remove people who are perceived as a threat can provide staff with a sense of immediate safety, which may inadvertently reinforce their use. To address this, I wanted to explore whether supporting staff to manage their emotions more effectively could reduce their reliance on restrictive practices, and foster a more compassionate approach to care.

As part of my research, I introduced compassion-focused support groups for staff in several forensic mental health wards, advocating for a more empathetic and patient-centred approach. These groups tried to equip participants with skills to better manage challenging emotional experiences while fostering greater compassion for both themselves and the people in their care.

The aim was to help staff cultivate an inner sense of safety, reducing their reliance on restrictive practices as a means of managing their own feelings of threat. This intervention was encouraging, leading to reductions in the use of restrictive practices in some conditions – demonstrating the potential of using compassionate care for these purposes.

My study was the first of its kind – bur these initial results highlight the need for further research into how the emotional management of staff influences care decisions. The journey toward change is slow, but it is possible. Compassion may hold the key to addressing a deeply entrenched issue that has shaped the treatment of mental health patients for centuries.


Get your news from actual experts, straight to your inbox. Sign up to our daily newsletter to receive all The Conversation UK’s latest coverage of news and research, from politics and business to the arts and sciences.

The Conversation

Daniel Lawrence is affiliated with the Labour Party.

ref. Physically restricting mental health patients can often harm them – my new study suggests compassion could change that – https://theconversation.com/physically-restricting-mental-health-patients-can-often-harm-them-my-new-study-suggests-compassion-could-change-that-244782

Counting the climate costs of abandoned shopping trolleys

Source: The Conversation – UK – By Neill Raath, Assistant Professor of Sustainable Materials and Manufacturing, University of Warwick

Richard Johnson/Shutterstock

Despite the steady growth of online shopping, a majority of the UK public still prefers to buy groceries at the supermarket.

Shopping trolleys can help us lug our purchases back to the car, but some shoppers are evidently taking them further afield. In 2017, 520,000 trolleys were reported as abandoned in the UK. Sunderland in north-east England alone reported 30,000 abandoned trolleys between 2020 and 2022. Likewise, 550 trolleys were collected in a single day in western Sydney, Australia.

Supermarkets employ a range of methods to stop trolleys leaving their premises, including coin slots, vertical bars (to stop trolleys leaving the shop floor), wheel-locking mechanisms and car park wardens. Despite these efforts, abandoned trolleys still blight the landscape and need to be collected.

Many supermarkets use commercial collection services, such as Wanzl TrolleyWise or TMS Collex. These companies typically use diesel vans to survey suburban areas, collect trolleys and return them to supermarkets. They also offer to refurbish weathered or damaged trolleys, sometimes by applying a zinc-based coating to protect against corrosion – a process known as regalvanisation.

We are researchers at the University of Warwick who wanted to understand the environmental impact of trolley abandonment. So, we set out to investigate it.

Collecting versus manufacturing

How does the environmental impact of using vans to rescue abandoned trolleys compare with losing these trolleys to excessive damage or corrosion and having to make new ones?

Our study used a standardised methodology known as life-cycle assessment to analyse the potential environmental impact of collecting and handling abandoned shopping trolleys within an area of Coventry, a city in the English West Midlands, which includes our university campus.

We spoke to trolley suppliers, who told us trolleys used at the supermarket in Coventry were most likely made in Spain. This was incorporated into our model.

A shopping trolley wedged in a hedge.
A trolley discovered by the author, abandoned in a bush near a car park.
Neill Raath

Through conversations with our university’s estates department and commercial collection services, we established that approximately 30 trolleys were collected a week on average in the area surrounding the Tesco supermarket in the Cannon Park shopping centre.

Our model assumed that a bulk transport of 50 trolleys is sent twice each year to be refurbished, in a round trip of 220km between Coventry and a refurbishment facility based in the UK that was noted on stickers placed on refurbished trolleys.

Vans collecting 520,000 abandoned trolleys in a year could emit the equivalent of 343 tonnes of CO₂ (the annual equivalent of driving 80 petrol cars). If we imagine that 10% of these 520,000 trolleys have been left outside too long and need to be regalvanised then the total global warming impact increases by 90% to the equivalent of 652 tonnes CO₂ (roughly the same as 152 petrol cars being driven for one year).

This is quite a surprising increase for such a small number of trolleys. It suggests that the real problem lies with the environmental impact of manufacturing.

Most of the emissions can be avoided

We found that one trolley would have to be collected 93 times by a diesel van to have the same environmental impact as manufacturing a new one.

Our results showed that the emissions incurred during the diesel van collection phase were only 1% of the manufacturing impact, and the regalvanisation stage was only 8%. We might wonder whether switching to electrically powered collection vans might help. While the emissions would be reduced, the impact of using diesel vans is still minuscule compared to that of making new trolleys.

We found that the highest environmental impact stemmed from manufacturing, which was mainly attributed to making and replacing the steel frame of the trolley.

These results reinforce the benefits of following the circular-economy principle of keeping trolleys in use for as long as possible, and avoiding manufacturing to replace abandoned ones.

Would anything change if we switched to plastic trolleys? Other researchers have investigated the effect of changing trolley materials and have found that trolleys made of polymers have many benefits compared with steel: they use less material, are less dense (a benefit for collection vans that emit less by driving around lighter products) and do not require protective coatings, which themselves have an environmental impact.

A steelworks.
Blast furnaces at conventional steelworks are very carbon-intensive.
Pedal to the Stock/Shutterstock

However, if these polymer trolleys were to be sent to landfill (or left to deteriorate in the environment), they could release carcinogenic chemicals, as well as microplastics, as they break down. This leads us back to the importance of keeping products in use.

Abandoning trolleys is bad for the environment, with a potential global warming impact equivalent to 0.69 kg CO₂ for collecting one trolley and returning it to a supermarket. If we multiply this by the potential 520,000 abandoned trolleys a year, this figure becomes quite big.

Preventing trolley abandonment should be a priority not just for supermarkets, but for the general public as well. However, once a trolley is abandoned, it is far better to collect and refurbish it than to let it fall out of use and manufacture a new one, as 92–99% of the environmental impact can be avoided.

While it is unlikely that we can ever stop trolleys being abandoned, we hope that next time people see a trolley in an alley or park bush, the potential environmental impact of losing this trolley to service would be apparent.


Don’t have time to read about climate change as much as you’d like?

Get a weekly roundup in your inbox instead. Every Wednesday, The Conversation’s environment editor writes Imagine, a short email that goes a little deeper into just one climate issue. Join the 45,000+ readers who’ve subscribed so far.


The Conversation

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.

ref. Counting the climate costs of abandoned shopping trolleys – https://theconversation.com/counting-the-climate-costs-of-abandoned-shopping-trolleys-258500