All posts by Nigel Boldero

Climate crisis: what can trees really do for us?

Rob MacKenzie– Professor of Atmospheric Science, University of Birmingham

Rose Pritchard– Presidential Fellow in Social-Environmental Systems, Global Development Institute, University of Manchester

By the power of sunlight, forests turn huge amounts of carbon in the air into food: sugars for themselves and leaves, bark and roots that feed animals and microbes. Respiration, which happens in the cells of all living things in the forest, releases energy from that food and carbon dioxide (CO₂) back into the air.

As the amount of carbon in the atmosphere rises, this eat-and-be-eaten cycle increases to keep up. Metabolically, trees are running just to stand still. In the course of all this cycling, forests are locking up the major part of the 33% of human-caused emissions removed from the atmosphere into the land each year.

I (Rob) work in a forest full of beautiful 175-year-old oaks. Global CO₂ levels were around 280 parts per million (ppm) when these trees were seedlings. Now global atmospheric concentrations exceed 415ppm and are rising rapidly. Should these oaks reach 200 years old (not old for an oak), they will be surrounded by air containing around 550ppm of CO₂. Can the world’s mature forests stand these changing conditions and continue to offset some of our emissions from burning fossil fuels?

Carbon current accounts

To find out, my colleagues and I at the University of Birmingham’s Institute of Forest Research use a free-air CO₂ enrichment facility. Imagine a dinosaur-free Jurassic park with 102, 25 metre-tall towers treating forest patches with CO₂-enriched air that replicates the mid-century atmosphere: 565ppm – 150ppm above present levels. Then we measure everything we can: the width of tree stems, the size, weight, and chemical make-up of leaves, the branching architecture of the roots and much, much more. In this way, we record changes in the forest’s manufacturing of stuff, and in its health.

Our first results are in. In the canopy, photosynthesis rates are up to a third higher on sunny summer days in the CO₂-rich patches. Over a growing season, the increase is about a fifth. These are big numbers: imagine if your annual income went up by a fifth. Photosynthesis is the forest’s carbon income.

Since we began this experiment in 2017, the forest patches exposed to higher CO₂ appear healthy and productive. That may seem unsurprising. After all, plants love CO₂ so much that farmers add it to greenhouses to supercharge fruit and veg growth.

An aerial view of a patch of forest encircled by metal towers.
The experiment is designed to study forest growth under some of the conditions that will prevail in 2050. Deanne Brettle, Author provided

But forests are not nurtured. They have to fend for themselves, winning (with their fungal partners) all the nutrients they need to balance any CO₂ bonanza from the earth on which they stand. Extra CO₂ photosynthesised into sugar can be too much of a good thing, like an imbalance in our diet.

Think of forests as carbon current accounts, bringing carbon in through photosynthesis and spending it on all the energy-giving respiration that keeps everything in the forest alive. In a healthy and productive forest, a little more comes in than goes out of the current account at the end of every year.

Forest carbon current accounts can hold carbon for decades, occasionally centuries, in their standing timber and roots and soil, tiding us over the 21st-century peak in atmospheric CO₂ – a carbon cashflow crisis caused by burning fossil fuels and deforestation.

Well-managed forests can yield timber and fuel while reducing carbon in the atmosphere. But carbon savings accounts, which put the stuff away for millennia – by pumping it into reservoirs deep underground, for example – are also needed.

People and trees

Scientific models have estimated how much tree planting or reforestation is needed to offset rising CO₂ in the atmosphere. As with most efforts to translate theory into action, the real-world experiences of actually doing this are often very messy indeed.

How reforestation campaigns are funded and tree planting incentivised will determine where and which kinds of trees are planted. How the land is ultimately governed will also decide how long new trees survive. International efforts to grow the planet’s tree cover show how difficult these barriers can be to overcome.

A recent study in northern India found that decades of expensive tree planting programmes had not increased total canopy cover. And the planted areas did not offer any major benefit to local people, like new food or firewood. This was because new trees couldn’t be planted on nearby farmland, and so were instead added to areas that already had some tree cover, reducing the potential carbon savings of the whole endeavour. Local foresters were also preoccupied with meeting tree planting targets, rather than nurturing the kinds of forests and trees which local people valued.

Rows of tree saplings coated in plastic.
Effective tree planting is usually a matter of quality, not quantity. Dennis Wegewijs/Shutterstock

Land is never just about carbon. Trees and forests shape microclimates and water cycles, support biodiversity and provide food, building materials and medicines to local people. They also have different cultural and spiritual values depending on where you are in the world. Forests are often nestled within landscapes occupied by all sorts of other uses, like farms and towns and cities.

Everyone has different preferences for how landscapes should look, and whose vision wins out depends on relationships of power. Researchers working in Uganda in 2014 described what they called carbon colonialism: plantations established to offset greenhouse gas emissions destroyed the crops and burial sites of local people and convicted those accused of trespassing on what had previously been public land. This is just one among many examples of tree planting, however well-intended, blighting lives.

Using trees as a tool becomes unjust when it involves asking poorer rural people to compromise their livelihoods so that wealthier people or nations can continue to consume fossil fuels. Rather than asking if trees can help tackle the climate crisis, perhaps we should ask how much the world should really rely on trees as a climate solution.

There is a lot to be learned from efforts that have managed to increase tree cover and offer benefits to local people, like new income sources. Often, these initiatives are successful because they take local needs and values seriously. Local and indigenous people are leaders in this process, not afterthoughts. And ultimately, reforestation will succeed if it benefits people, as well as the planet.

COP26: the world's biggest climate talks

This story is part of The Conversation’s coverage on COP26, the Glasgow climate conference, by experts from around the world.
Amid a rising tide of climate news and stories, The Conversation is here to clear the air and make sure you get information you can trust. More.

Wildlife gardening jobs for October

From feeding to creating habitats, find out what you can be doing for wildlife in October.

By BBC Gardeners’ World Magazine

Garden wildlife jobs - make habitat piles

October is a significant month for wildlife. For mammals, amphibians and birds, there’s less invertebrate food around, as snails, caterpillars and other critters hunker down for winter. This means they spend more energy looking for food, just when they need it the most.

Hedgehogs are fattening up ahead of going into hibernation – they need to be large enough to survive several months without food, so leaving meat-based cat or dog food out for them can make all the difference. Birds don’t hibernate, so need to consume enough calories per day to survive each night. Most reptiles will already have entered hibernation, while frogs, toads and newts will be well on their way.

Some species of bee and butterfly may still be on the wing, emerging on sunny days to feed from late-summer flowers. Providing food is therefore a key October job.

Elsewhere in the garden we should be creating habitats for hibernating wildlife, and leaving areas alone to avoid disturbing anything. Think of your garden as not belonging to you for the next few months – take a back seat and leave the tidying until spring. The wildlife needs it now.

Think of your garden as not belonging to you for the next few months – take a back seat and leave the tidying until spring.

Think of your garden as not belonging to you for the next few months – take a back seat and leave the tidying until spring.

Browse our list of wildlife gardening jobs for October, below.

Leave windfall apples where they land

Garden wildlife jobs - leave windfall apples

Garden wildlife jobs – leave windfall apples

Migrant birds such as redwings and fieldfares flock to gardens in bad weather and feast on windfall fruit. So don’t clear it away, leave it in place . Late-flying butterflies and other insects may also feed from them when sources of nectar have dried up.

How to grow apples

Make habitat piles

Garden wildlife jobs - make habitat piles

Garden wildlife jobs – make habitat piles

Hibernating wildlife typically needs somewhere dry and undisturbed to bed down for the winter. Creating habitat piles from logs, twigs and other garden debris can provide the perfect spot for them. Choose an out-of-the-way corner that you won’t disturb, and build your pile, starting with the largest items. Damper areas at the bottom will attract hibernating amphibians, while drier areas will support insects and small mammals.

Three ways to create a dead wood habitat

Provide calorie-rich food for birds

Garden wildlife jobs - leave calorie-rich food for birds

Garden wildlife jobs – leave calorie-rich food for birds

We should feed the birds all year round, but in winter garden birds need extra calories, to provide them with the energy they need to survive the cold nights. Choose calorie-rich peanuts, sunflower hearts and suet products, and keep the feeders topped up as the birds will come to rely on them.

Making fat cakes for birds, or check out our guides to the most nutritious bird food and stylish bird tables.

Plant bare-root plants

Garden wildlife jobs - plant a bare-root tree

Garden wildlife jobs – plant a bare-root tree

Now’s the perfect time to increase your stock of wildlife-friendly trees and shrubs by planting bare-root plants. Choose berry-bearing holly, guelder rose, rowan and hawthorn, or invertebrate favourites such as birch and hazel. You’ll provide a lasting source of habitat and food for a range of species.

How to plant a bare-root hedge. Looking for the perfect spade? We’ve tested 14 of the best garden spades.

Plant spring-flowering bulbs

Garden wildlife jobs - plant spring-flowering bulbs

Garden wildlife jobs – plant spring-flowering bulbs

Don’t forget to plan ahead for spring. Bumblebees hibernate for up to seven months, and are only a few hours away from starvation when they emerge from hibernation. Planting nectar-rich bulbs now will ensure there’s plenty of food for bees when they wake up. Choose crocus, snake’s head fritillary and grape hyacinths, for a bee-friendly feast.

Five best April-flowering bulbs. To help you save time when it comes to planting, we’ve tested the best bulb planters to buy in 2021.

Feed hedgehogs

Garden wildlife jobs -feed hedgehogs

Garden wildlife jobs -feed hedgehogs

Leave out chicken-flavoured cat or dog food, or bespoke hedgehog biscuits, for hedgehogs until it’s no longer taken. Don’t forget to leave out a dish of water as well. Remember to call your local hedgehog rescue if you see a hedgehog out during the day – it could be very ill or not weigh enough to survive hibernation.

How to provide shelter for hedgehogs. Alternatively, if you’d like to provide them with the perfect home, we’ve selected seven hedgehog houses.

Take down your bee hotel

Garden wildlife jobs - take down your bee hotel

Garden wildlife jobs – take down your bee hotel

Leaving your bee hotel up during winter can expose it to damp conditions, which could put the overwintering bees at risk of succumbing to fungal infections. Take it down and pop it in your shed, instead, where it can remain dry. Don’t bring it into the house as conditions will be too warm and the bees might emerge early from their cocoons. Don’t forget to pop the bee hotel back up in March.

Types of bee hotel

Trim hedges

Garden wildlife jobs - trim your hedge

Garden wildlife jobs – trim your hedge

It’s illegal to disturb nesting birds in spring but, while they won’t start nesting until April or May, some species establish breeding territories as early as January. Trimming hedges now will therefore ensure minimal disturbance.

Best plants for a wildlife hedge. Why not check out our test of the best 15 hedge trimmers to buy in 2021, or if you prefer to do things by hand, find out which of the hedge shears came out on top in our test of the best garden shears.

Plant winter clematis

Garden wildlife jobs - Clematis 'Freckles'

Garden wildlife jobs – Clematis ‘Freckles’

Winter-flowering plants such as Clematis ‘Freckles’ and winter honeysuckle, can bridge the nectar gap between autumn and spring. Bees that emerge early from hibernation on sunny days are in danger of dying if they don’t find a source of food quickly, so by providing a constant source of nectar in your garden you can help them on their way.

Seven clematis for every season. Once you’ve planted them, find inspiration with our guide to the most stylish and practical obelisks and plant supports for climbers.

Mulch your borders

Garden wildlife jobs - mulch your borders

Garden wildlife jobs – mulch your borders

You might not think that mulching helps wildlife, but by collecting leaves each autumn and then using them to mulch your borders the following year, you are replicating the natural cycles of death and regeneration you would find on the woodland floor. Leaf mould is a fantastic resource that will increase worm activity in the soil, as well as provide habitats for critters such as centipedes and beetles to hide. Birds, too, will pick among the debris for a feast.

How to make leaf mould from autumn leaves

England has managed its countryside badly for a century – what has gone wrong and how it can be fixed?

Philip Donkersley– Senior Research Associate in Entomology, Lancaster University

A century of managing the English countryside badly has led to collapsing ecosystems, growing threats from flooding, more farms going bust than ever before and a global climate crisis still lacking any coherent and practical approach to sorting it out.

As the UK hosts the COP 26 conference in Glasgow, where the world’s leaders discuss plans for addressing climate change, it would be an excellent time to signal a new approach to countryside management.

A recently published Parliament Office for Science and Technology report on sustainable land management proposes a new approach to countryside management in England, based on 18 months of research, over 500 scientific studies and interviews with researchers, public policy executives and key practictioners in the field.

Solving this crisis will take massive and radical shifts. This will involve hundreds of decisions by different groups: farmers, national and local governments, banks, land agents, industry and the public; and they all need to work together.

How did it get so bad?

The UK, and particularly England, is one of the most crowded countries in Europe, which places significant pressures upon land and land use. Unlike the rest of Europe, the last time England experienced a major redistribution of land ownership was the dissolution of the monasteries in the 16th century.

British National Ploughing Championships held at Marden, Kent. Smudge 9000/flickr

The second world war marked a huge change how land was managed. Today’s farming in England is still largely shaped by 1947 Agriculture Act, which pushed self‐sufficiency in food production. Industrialised agriculture led to a reliance on diesel vehicles, inorganic fertilisers and chemical pesticides. This led to the end of horse-drawn ploughing and leaving fields fallow to recover. Efficiency went up, but the environmental costs were hidden until recently.

Today’s problems

Farmland birds like the European turtle dove numbers have declined. Smudge 9000/flickr

The Nature Conservancy Council estimated that by 1984, only 3% of Britain’s natural grasslands were left undamaged by agricultural intensification. Over the same time, the amount of land farmed in the England has grown to around 75%. As a result, both habitat diversity on farms and biodiversity across the country have been dramatically reduced.

Over the 20th century, the nation’s priority was to feed everyone, but not to protect the natural environment. Arguably, this was successful – farm productivity rose sharply (though food imports also grew after the UK joined the EU in 1973).

Trying to feed the nation and solving a biodiversity crisis would always be a challenge. Unfortunately, governments of the world are now also dealing with a global threat of human-caused climate change, flooding caused by bad river management, and widespread destruction of culture and heritage. Farmland biodiversity decline shows that when attention is focused on just one issue (food security), it is easy to cause more harm elsewhere.

Great Ridge from Mam Tor, Derbyshire. Pete Quinn/Flickr

The problem has been that governments and land managers have always tried to fix problems individually. Only by considering each area’s connection to others can sustainable change be achieved.

Read more: How gardeners are reclaiming agriculture from industry, one seed at a time

Working together

Fortunately, there are many excellent examples of this kind of practice happening in England today.

Haweswater reservoir, Cumbria. Pat Neary/flickr

In the Lake District, around the Haweswater reservoir, there are two Herdwick sheep farms managed by farmers, wildlife charity the RSPB and the water company United Utilities. Here, the three parties maintain the land and their interests by working together. They manage the land to ensure higher water quality downstream by limiting sheep on the fells where rivers surface. This land is now a haven for endangered species, including England’s rarest fish, and birds like the Firecrest.

London floods 2021. Francisco Antunes/flickr

The reasons for floods (like those in July 2021 in London) happen along the whole length of the river. Community businesses like Ullswater CIC take what is known as a “catchment approach” to flood management, planting trees and managing channels across the river’s length. Lancaster University research shows taking this bigger picture approach, combined with natural flood management strategies, is more effective in preventing flooding than any man-made barrier.

Burnett moth. Cécile Boulanger/flickr

We need to reverse global biodiversity loss, improve ecosystem resilience and stabilise the environment. Although bigger areas are often better for wildlife, research shows wildlife corridors can be very effective. These are ways of connecting areas of habitat for wildlife, massively increasing space for endangered animals, insects and plants, like a network of sites all working together. Natural England plans to create local and national networks) of these spaces.

Sites such as the Knepp Estate in West Sussex bridge environmental and agricultural thinking. Farming intensity has been hugely reduced to allow for regeneration of the natural environment, without compromising the bottom line.

Government must integrate nature restoration with other landscape benefits (food, water, climate, biodiversity), while considering historical and cultural factors that have shaped the land. Examples of planting broadleaf forests on ancient peatlands, relocating ancient woodland are the result of not listening to local knowledge and experience. Changing this approach will help England keep producing clean water and enough food to feed everyone, limit flood damage, restore ecosystems and become more resilient to global climate change. If not, the risk of another 100 years of bad land management will continue to impede any progress in solving environmental catastrophes.

Parks and green spaces helped us get through lockdown – but not everyone has equal access

Hannah Burnett– PhD Researcher in Public Health, University of Glasgow

Jonathan Olsen-Research Fellow, University of Glasgow

Rich Mitchell-Professor Of Health and Environment, University of Glasgow

What we could all see was solace: it was clear that nature at its loveliest and most inspiring, in springtime’s wondrous transformations, could offer people comfort at a moment of tragedy and great stress.

Michael McCarthy, nature writer

For many, the COVID-19 pandemic has had a damaging impact on their psychological health, but the chance to get out into nature provided some much needed respite and escape during a difficult year.

Following restrictions in March 2020 that saw the UK closing non-essential retail and hospitality, and limiting people to leaving the house once a day for essential reasons, it’s no surprise that some discovered a heightened appreciation of their local green spaces. Whether it was a park, a nature reserve or a canalside walk, stories of people finding comfort and consolation in nature at this distressing time have been well documented.

This was emphasised by the UK housing, communities and local government minister, Robert Jenrick, who stated that parks and other public green spaces must be kept open for “the health of the nation”.

However, our research during this period found that the majority of the UK population (63%) were spending less time in green spaces than before lockdown. This was likely linked to feelings of anxiety when venturing out of the house, especially for those over 70 or anyone advised to shield for health reasons.

We conducted an online survey through YouGov to investigate how the UK population had altered the amount of time spent in parks during the first lockdown, and whether their experiences of these places had changed. The survey was answered by 2,252 adults from across the UK, drawn from a representative panel of over 800,000 participants. In this research, we defined green spaces as any place outside of the home where people can experience nature, plants and trees.

A goldfinch sitting in a cherry tree in full blossom with white flowers.
Immersing ourselves in nature can help relieve anxiety. Mark Caunt/Shutterstock

Widening gap

Inequalities in the use of green space, and changes in the way it is being used, are likely to be associated with occupation, especially during lockdown, when certain workers were advised to work from home. One report stated that less than 10% of manual workers worked from home during the initial lockdown, compared to 75% of managerial and professional workers.

This data highlights that those in the professional group had more opportunity to visit green spaces during lockdown and so were more able to benefit. Manual workers unable to do their jobs at home may have had less time and opportunity to visit green spaces – such as walking in the local park.

We found that the initial lockdown increased existing inequalities in the use of green spaces. Before the pandemic, manual workers like shop assistants and labourers were a third less likely to visit green spaces than those who worked in managerial occupations, such as business owners and senior executives. This difference could be partly explained by a lack of access to decent parks for more disadvantaged groups, or the fact that these groups are less interested in using green spaces.

This pattern of inequality actually worsened during lockdown, with the difference in use increasing between the two social groups. We found that manual workers were two-thirds less likely to visit a park after lockdown restrictions were enforced. This is despite ONS research finding that parks are most accessible in the poorest areas of the UK.

Read more: Ecotherapy aims to tap into nature to improve your wellbeing

However, other research shows that poorer areas are more likely to have low-quality green spaces. This could mean that even if someone lived close to a park, they might not want to use it due to a lack of amenities such as seating and toilets, or high crime levels or too much litter.

Older adults (aged 65+) and women spent less time in green spaces during lockdown, compared to younger age groups and men. These will likely lead to widening health inequalities if no action is taken, and compound the devastating impact of the pandemic for older people, who experienced more social isolation. This is because they were less likely to be online and more likely to live alone and be shielding. Meanwhile, the inequality in use between the sexes could be explained by the fact that women spent more time on childcare than men during the first lockdown. They also make up 77% of the NHS workforce and 89% of nursing staff in the UK.

Benefits of green space in lockdown

Green space has positive effects on physical and mental health, especially through things like “forest bathing” – a mindful, immersive walk in the woods, and green prescribing, where doctors advocate a dose of nature rather than medication. Both are currently being researched and implemented across the UK.

But how did green spaces affect the population’s mental health during the first lockdown? We know that suicidal thoughts increased during lockdown and antidepressant use is now “soaring”.

Our research found that around two-thirds (65%) of individuals reported that spending time in green spaces benefited their mental health more during the lockdown than before. This would suggest that green spaces have the capacity to counteract the impact of the pandemic on the population’s mental health.

Previous research has shown that the positive effects of being immersed in green space can help reduce health inequalities by benefiting less advantaged people more. Other studies have found that inequalities in mental wellbeing are smaller among those who have better access to green space compared to those who do not have access to a local park. More recently, a report by Public Health Scotland found that nine in ten people said that being in green open spaces improved their mental health.

These findings emphasise the importance of parks and nature reserves remaining open during any future lockdowns. We believe our research highlights green spaces as an essential resource for mental health and wellbeing, and they must be protected and prioritised in any future fiscal squeeze to ensure the most disadvantaged and vulnerable do not lose out.

Climate fight: the world’s biggest negotiation – introducing a new podcast series

Jack Marley– Environment + Energy Editor and Host of the Climate Fight podcast series, The Conversation

Promotional artwork for Climate Fight podcast series

How will we actually tackle the climate crisis? And who gets to decide? As Glasgow gets ready to hold the COP26 climate summit in November, The Anthill Podcast is launching Climate fight: the world’s biggest negotiation, a new podcast series taking you inside the fight for our planet’s future.

Climate fight: the world’s biggest negotiation – trailer

Many people breathed a sigh of relief when world leaders agreed to limit global warming to well below 2°C, and preferably below 1.5°C, at a summit in Paris in 2015.

But six years later, the UN issued a new “code red for humanity” in its latest report on climate change. Scientists on the Intergovernmental Panel on Climate Change (IPCC), said global warming would exceed 1.5 or even 2°C above pre-industrial levels this century, “unless deep reductions in carbon dioxide and other greenhouse gas emissions occur in the coming decades.”

World leaders, scientists and climate activists will meet in Glasgow for the 26th Conference of the Parties on October 31, to try and agree new targets on emissions reductions that keep this goal in sight. They’ll also discuss how to get there in a fair and just way.

In this podcast series, we’ll speak to some of the experts influencing climate policy, and to some of the people around the world who will see their lives change as a result of it.

Leading up to the summit, we’ll be exploring some of the big questions feeding into these negotiations. Questions about: money – and how much the world’s richest countries should give to protect the poorest parts of the world from the effects of climate breakdown; about the quest for net zero, and the technology needed to get there; about the trade-offs required to transition away from fossil fuels, particularly for those communities hit hardest by the shift to renewables. And what impact the voice of young people is having on the climate fight.

We’ll also be in Glasgow for the COP26 summit, talking to experts to unpack how the negotiations went.

The first episode will go live via The Anthill Podcast channel on October 6. Listen on The Conversation or follow The Anthill wherever you get your podcasts.

The Climate Fight podcast series is produced by Tiffany Cassidy. Sound design by Eloise Stevens and the theme tune is by Neeta Sarl. The series editor is Gemma Ware.

UK Research and Innovation (UKRI)

Climate fight: the world’s biggest negotiation is a podcast series supported by UK Research and Innovation, the UK’s largest public funder of research and innovation.

Children who eat more fruits and vegetables have better mental health – new study

Ailsa Welch– Professor of Nutritional Epidemiology, University of East Anglia

Richard PG Hayhoe– Senior Lecturer in Public Health, Anglia Ruskin University

School children eating a nutritious lunch together in the cafeteria.

Around 10%-20% of adolescents globally suffer from a mental health condition, such as anxiety or depression, according to the World Health Organization. It’s also been shown that half of all mental health conditions start by age 14. Given how important and formative adolescence is in a person’s life, finding ways of protecting or improving mental wellbeing in children and young people is extremely important.

We already know how valuable good nutrition and diet are for physical health – which is why experts recommend we aim for five servings of fruits and vegetables a day (“five-a-day”). More recently research has also started to suggest that nutrition could influence mental health. While more research is still needed in this area, our recent study found found that eating a more nutritious diet, rich in fruit and vegetables, and having healthier breakfasts and lunch habits were associated with better mental wellbeing in children.

To conduct our study, we used data from the Norfolk Children and Young People Health and Wellbeing Survey. This collected data on mental wellbeing and different things that impact it – such as socioeconomic status and age – from children at over 50 schools in Norfolk. This allowed us to investigate the importance of fruit and vegetable consumption and meal choices (such as what students ate for breakfast or lunch) with mental wellbeing in this age group.

Our analyses looked at 1,253 primary school pupils aged 8-11 years and 7,570 secondary school pupils aged 12-18 years. Using different questionnaires for the two groups, we assessed their mental wellbeing by asking them them to score how often they had the feelings described in statements such as “I’ve been feeling good about myself” or “I’ve been feeling loved”. The scores for each statement were added together to give a total score. The higher this total score is, the greater a child’s mental wellbeing.

We also asked students questions on their age, gender, health, living situation and adverse experiences (such as being bullied, or experiencing arguing or violence at home) alongside questions about what kinds of foods they typically ate. This was important so that instead of investigating nutrition and wellbeing on their own, we were able to take into account other factors that can impact a person’s wellbeing score. By doing this, we were able to show that the link between a healthier diet and better mental wellbeing still existed even after taking all these other factors into account.

Nutritious meals

In the secondary school group, higher fruit and vegetable consumption was associated with higher mental wellbeing scores – around 8% higher for those who ate five servings daily compared to those who ate none.

Teenage students in black uniforms queue to be served their school lunch.
A healthy breakfast and lunch were also important for mental wellbeing. Monkey Business Images/ Shutterstock

We also found that the wellbeing score varied depending on what type of breakfast or lunch participants ate. Compared to secondary school children who ate a conventional breakfast (such as cereal, toast or a cooked breakfast, like eggs), those who didn’t eat any breakfast had an almost 6% lower mental wellbeing score. Those who consumed only an energy drink for breakfast had an almost 7% lower wellbeing score.

Scores were similarly low for those who didn’t eat lunch compared to those who did. These associations were also similar in primary school children.

Our research also revealed that, on average, in a class of 30 secondary school children, four would have nothing to eat or drink before school, and three had nothing to eat or drink for lunch. We also found that only 25% of secondary school children ate five or more fruits and vegetables a day – and one in ten ate none.

These statistics would be concerning even without the link we have found with mental health, as poor nutrition is likely to impact on school performance as well as growth and development. While more primary school children ate breakfast and lunch, there was similarly poor fruit and vegetable intake.

To put our findings into perspective, having no breakfast or lunch was associated with a similarly detrimental effect on mental wellbeing as children witnessing regular arguing or violence at home. But as our study was observational, it’s difficult for us to prove the cause of poor mental wellbeing until trials are done to explore these links, fully understand why they exist, and really be certain whether better nutrition will improve mental wellbeing in children.

Our findings show that good quality nutrition needs to be available to all children and young people to improve mental wellbeing and help them reach their full potential. To do this, we could encourage more funding for breakfast clubs, make sure that all children eligible for free school meals use them, and that these meals contain at least two portions of fruits or vegetables. To achieve this, these approaches need to be supported by school policies and public health strategies.

Marburg in Germany prides itself on being a Blindenstadt – a city adapted to make life for the blind and partially sighted as easy as possible. But it owes this reputation and its inclusive social structure to a particularly innovative school.

By Sophie Hardach

The city of Marburg in Germany has positioned itself as a Blindenstadt, largely thanks to the influence of its school for the blind (Credit: GeorgHanf/Getty Images)

At the age of eight, Leon Portz was gradually losing his eyesight due to a congenital condition when he was given his first computer. By the age of nine, he had figured out how to speed up the machine-generated voice that read out websites and other electronic texts, allowing him to grasp the information faster. He now listens to texts at five times the standard speed, which is unintelligible to an untrained ear.

But his love of science only truly flourished when he moved from his hometown in central Germany to the nearby town of Marburg, a leafy, medieval university town, to attend a specialist school for the blind. As it turned out, that move transported him into a hotbed of inclusive innovation.

Marburg proudly calls itself a “Blindenstadt”, a city for blind and visually impaired people, due to its long history as a hub for accessibility. A ground-breaking educational institute for the blind, the Blindenstudienanstalt (or Blista) in German, was founded here during World War One, to provide opportunities for young men blinded in the war. The institute has spawned countless inventions for blind people since then, including a tactile mathematical font. It has also profoundly shaped the town around it, turning it into a place where, as Portz puts it, “everything is ideal for blind people”.

Some of the innovations that make Marburg so accessible also exist elsewhere. But the way they are joined up here is unique, Portz and other blind people who have lived in the town say. The clattering sound of guiding canes is ubiquitous in Marburg, as blind people navigate the town aided by beeping traffic lights, pavements and floors with ridges and bumps that act as tactile signals of hazards or barriers. Buildings often have raised maps and floor plans, while detailed miniature bronze models of major sights such as Marburg’s castle and town square allow blind visitors to feel the entirety of each landmark.

Other convenient features are a result of the town’s natural shape. Marburg is small and hilly, making it easy to orient yourself simply by noting if you are going up- or downhill. A web of accessible leisure facilities spans the city, such as a horse-riding school for the blind, and blind rowing, football, climbing and skiing clubs. The town’s university has Germany’s highest proportion of blind students, and the widest range of degrees taken by blind people.Many landmarks around the city have detailed scale models for partially sighted visitors to feel their way around (Credit: Alamy)

Many landmarks around the city have detailed scale models for partially sighted visitors to feel their way around (Credit: Alamy)

The Blista and its students have driven many of these innovations, developing everyday aids such as a foldable cane, but also, working with the university to improve accessibility across departments. Law and psychology are among the most popular course choices, as the materials are text-heavy and can be studied easily with aids such as screen readers. Now teachers and pupils from the institute are prising open another field: the natural sciences, which have long been beset by barriers for blind people.

“I don’t feel like a pioneer, but I guess I am one,” says Portz, who is studying biochemistry and computer science in Düsseldorf. He is the first blind biochemistry student there, and by his own estimate, one of fewer than a handful of blind chemistry students in all of Germany.

Chemistry remains relatively closed to the blind, due to the hazards of laboratory work, and the ubiquity of images, charts and graphs. But chemistry teacher Tobias Mahnke, who taught Portz at the Blista-associated Carl-Strehl-School in Marburg, argues there is no reason why his subject should be so restricted.

“No human being can see molecules, no human being can see atoms, and yet, chemistry education is so visual. Why? There shouldn’t be any disadvantage for blind people, given that sighted people can’t see all this, either,” he says.

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Mahnke, who is sighted, started working at the school in 2013. At the time, it didn’t offer an advanced chemistry class. Since then, he and his colleagues have developed an array of multi-sensory tools and methods for teaching natural sciences, supported by the chemistry faculty at Philipps University in Marburg, as well as funding from the charitable Reinhard-Frank-Foundation. Mahnke has written a master’s thesis on developing inclusive materials for teaching chemistry, and published some of his findings.

Unlike conventional science models used in classrooms, the Blista models are designed to reveal entire processes and wide-ranging relationships. For example, a three-dimensional model of a water molecule, developed by a group of chemists at different universities, can be squashed flat, to encourage students to think about how it is depicted in two dimensions. A 3D-printed plastic model of a curving river bed, developed by Mahnke’s colleague Tanja Schapat, is intended to be held under a tap. Students can feel where the water flows faster or slower, and how this shapes its contours. They then learn that where the bed is flatter, the water is shallower and therefore gets warmer in the sun, attracting fish and reeds.

The laboratory is adapted to blind pupils’ needs, with electric burners in perforated metal cases, instead of Bunsen burners with naked flames

“Most scientific experiments go far beyond seeing. You can touch things, something becomes warm or cold, you can smell and hear things, and in experiments with food, taste them,” says Mahnke as he shows the models via video. “In regular teaching, we focus on vision because it means I can demonstrate an experiment within five seconds, and it can be seen by 30 students. It’s fast and efficient for the teacher, but not for the pupils.”

In 2017, the school offered its first advanced chemistry course, and in 2019, demand was so strong that it offered two classes. The laboratory is adapted to blind pupils’ needs, with electric burners in perforated metal cases, instead of bunsen burners with naked flames. Mahnke and his colleague Tanja Schapat have developed a method for teaching pupils about heat and fire, using heat-sensitive swelling paper to allow them to explore the properties of a burning candle. A special sensor, developed at the school in the 1990s, emits a high or low beep when a liquid brightens or darkens during a chemical reaction.

During the pandemic, Mahnke taught students about the Covid-19 infection curve using raised charts printed on swelling paper. When the school closed to stop the spread of the virus, teachers posted models to home-schooling students. Each model is tested by pupils at the school, further refined with their input, and produced in the school’s in-house workshop.

In recent years, the Carl-Strehl-School has started accepting a limited number of sighted children, who learn alongside their blind classmates using multisensory materials, which in their case also incorporate sight. Research has shown that children and adults learn better when they can grasp new information with multiple senses, and not just visually. Mahnke says in his own experience, “multi-sensory experiences lead to much deeper and longer-lasting learning”.

For Portz, it was not just the school that broadened his world. He fondly recalls moving around Marburg with confidence, assisted by beeping traffic lights, talking bus stops, and a sighted population very used to interacting with the blind. Bus drivers in Marburg are trained to stop to give blind passengers easy access, shop assistants routinely deal with blind customers, and many restaurants offer menus in Braille script. He’s encountered some of these elements in other cities, but never in the form of such a comprehensive web.

“In Marburg, all these individual elements are very well-connected, and there are few gaps,” he says. “It’s also the mentality in Marburg. There’s the Blista, and many stay on to study at the university, so there are many blind people, and every institution is confronted with that, sooner or later.”Marburg's blind football team has been particularly successful over the years (Credit: Oliver Hardt/Getty Images)

Marburg’s blind football team has been particularly successful over the years (Credit: Oliver Hardt/Getty Images)

Uwe Boysen is a retired blind judge and former president of Germany’s association of blind and visually impaired students and professionals, the DVBS, which was founded in Marburg. He attended the Carl-Strehl-School and then studied law in Marburg in the late 1960s. In his opinion, the sense of community and self-help that has evolved in Marburg plays a crucial part in sparking innovation: “It gives you courage, it makes you dare to try out new things.”

That self-help spirit shaped Boysen’s own educational path. Professional opportunities for blind people were more limited when he was a student, though he estimates there were about the same number of blind judges in Germany as there are today, over 100, also because of the war blind. He and his blind peers invented many aids on the fly, swapping recorded tapes of their textbooks, and later, using their legal skills to campaign for more rights.

Bahaddin Batmaz, a blind software developer and accessibility trainer in Marburg, argues that many of its accessible features hold important lessons for innovation as a whole. One is that good design benefits everyone. He gives the example of the talking bus stops, which announce the next bus and its destination when a button is pressed. In his experience, many sighted people find this function convenient, too. Similarly, when he makes a website more accessible to screen readers, its search ranking usually jumps as well, because the underlying technology is the same.

“Linking together technological innovations, and the human and social factor, is hugely beneficial,” he says. “If you’re not constantly wondering how to cross the road, you’re less stressed. You’re not already totally overwhelmed by this stupid road, and then you’re also more open for innovation, and more accepting of others.”

Dago Schelin, a sighted filmmaker and media studies researcher at the Philipps University, comes to a similar conclusion in a case study of Marburg as a model for inclusive innovation. He and his co-authors describe it as a “smart city for the blind”, and argue that “Marburg appears to specialise in an alternative mode of smartness”. Instead of revolving around digital technologies, this type of smartness is more human-oriented. It centres on supportive interactions between differently abled people, and on accessible institutions. Schelin and his co-authors suggest that Marburg might become “a reference for prospective smart cities”, with accessibility perhaps becoming “one of the criteria for a city’s smartness status.”

I think the most difficult barriers are the ones in people’s heads – Leonore Dreves

Schelin, who is from Brazil, experienced this innovation-boosting effect himself when he moved to Marburg in 2014. He met blind people interested in filmmaking, and developed multisensory methods for teaching them. “It strengthened my notion that filmmaking is a community effort,” he says.

Leonore Dreves, a blind software developer in Heppstadt in southern Germany, leads the science, technology, engineering and mathematics sub-group of the DVBS professional association. Most members of the group work in information technology, a comparatively accessible sector. But even there, too many digital barriers remain, according to Dreves. Changing human attitudes is also part of the challenge: “I think the most difficult barriers are the ones in people’s heads. In my own case, as a woman and blind person, I had to prove myself for a long time before my colleagues accepted that I can do it just as well as them.”

Around the world, blind innovators are slowly dismantling some of those barriers. The chemist Mona Minkara is designing an inclusive STEM curriculum, the computer scientist Chieko Asakawa is developing accessible artificial intelligence, and the astronomer Wanda Díaz-Merced is using sound to study space, to name just some.

In Düsseldorf, Portz continues to work on making his own environment more accessible. Sighted friends help him with his image-heavy textbooks, describing charts and pictures. During the pandemic-related university closures, he listened to his recorded lectures at double speed, slowing down for the more complex bits. He still discusses new ideas for science materials with his former teacher, Mahnke, and continues to feel inspired by his old school. “It gave me a super strong push,” he recalls of his time there. “I realised what was possible, and what can be made possible.”

Growing bigger prickly hedges can reduce the chance of extreme weather – and a lot more

Mick Hanley– Associate Professor (Reader) in Plant-Animal Interactions, University of Plymouth

In highlighting how Britain lost half its hedgerow network in only 75 years following the post-WWII move to modernise farming, a recent report from the Council for the Protection of Rural England points out how hedgerows can reduce climate warming by naturally helping to remove CO₂ from the atmosphere.

Simply allowing existing hedges to get bigger could double overall carbon sequestration capacity (the process of capturing and storing atmospheric CO₂). The build-up of “greenhouse” gasses such as CO₂ causes the atmosphere to warm, which in turn increases the likelihood and severity of extreme weather events, such as flooding, wildfires and hurricanes.

The CPRE argue that a 40% increase in the UK’s hedgerow cover could provide a net CO₂ sequestration potential of 18.5 million tonnes. That may be a fraction of current UK CO₂ emissions 354 million tonnes in 2019, but the potential contribution to the climate problem is significant.

What can hedges do for the climate?

As ecologists we have to worry about many things: invasive species, habitat loss, overexploitation and pollution. But climate change is the big one.

Plants naturally capture carbon during the process of photosynthesis, the process of producing food for the plant to survive. The ability to couple CO₂ with water and generate sugar using solar energy is the most remarkable and important event in evolutionary history and might just help us prevent climate catastrophe by naturally capturing this key greenhouse gas.

Although the ability to sequester carbon varies between tree species and different management practices, it is estimated that mixed hawthorn/blackthorn hedges (the most common species in British hedgerows) can store up to 42 tonnes of carbon per hectare.

The most extreme (yet wholly credible) scientific predictions for how climate change will affect the planet are so harrowing that I don’t even tell my final year undergraduate students. What is clear is that if humanity does not take responsibility at the COP26 meeting in Glasgow (the 2021 United Nations climate change conference), it is probably too late to completely mitigate the consequences. But it appears that there are some actions that can help – and growing more hedgerows may be one of the easiest ones.

Read more: How summer 2021 has changed our understanding of extreme weather

Hedgerow heritage

Hedgerows should be the farmer’s friend, but after Hitler’s U-boats threatened Britain’s food supplies during the second world war, post-war governments impressed the need for agriculture to modernise. In came a raft of chemical fertilisers, pesticides and larger machinery. Out went intimate fields and the web of hedges established around them hundreds of years earlier.

Farmers actually received grants to grub them out, many doing it simply because they were paid to, rather than any obvious benefit to farming efficiencies. It is only since they disappeared that it has become apparent that they actually contributed a great deal to agricultural production and the wider rural landscape.

I am lucky enough to live in a part of the UK that still has hedgerows. They are among the numerous features that delight the summer influx of migrants to south-west England. Many older visitors recall the rural landscape of their youth and the traditional hedges around fields. Thanks to hedges, late spring brings a kaleidoscope of red campion, bluebell and the white flowers of stitchwort to the roadsides of Devon and Cornwall. With the flowers comes a posse of insects competing for the nectar and pollen these flowers provide.

Aerial view of fields in Cornwall.
In Cornwall, many fields still retain their hedgerows as seen in this aerial view of land close to St Ives. Tim Woolcock/Shutterstock

Aesthetics are, however, only part of their value. Bees and hoverflies that feed from, and make their homes in, Britain’s hedgerows provide a key pollination service to farmers. Other insects spill out from the hedgerow to prey on crop pests and so contribute another critical ecosystem service to society. Simply retaining a living biological structure around the edges of fields helps retain soil and filter out agrichemicals that might otherwise leach into the wider environment.

Modest investment

A relatively modest taxpayer commitment of £310 million over 28 years (less than £10 per working adult in the UK) could attract a near four-fold return on investment, with additional benefits for job creation, cleaner air and enhanced water use.

The CPRE also argues that urban planting might also have major benefits for mental health and well being with plenty of scope to increase upon the mere 38% of urban roads with any form of hedgerow at present. It is also likely that reinstatement of rural hedgerows will make the countryside more attractive for visitors, says the CPRE.

The UK government will need to offer targeted subsidies to farmers and other land managers to replant hedgerow trees and then manage them in appropriate but well understood ways to maximise carbon-capture and biodiversity potential. There was a system of well-established and broadly successful EU agri-environment schemes in place in Britain before Brexit to encourage hedgerow expansion and management.

The National Farmers Union is lobbying government to replace and improve these schemes, but even with legislation and appropriate government support, it takes time to reinstate biodiversity.

That said, I planted a native hedge instead of an expensive, wind-catching fence when I moved house ten years ago, and saw that it was possible to grow a two-metre tall, biodiverse hedgerow within a decade. Surely if I can do it in my back garden, farmers can do even better.

An Audio Meditation to Improve Nature Connectedness and Mental Health

Sometimes, we can’t get out into nature and our research shows that people typically spend less than five minutes each day in green space. Developing…

An Audio Meditation to Improve Nature Connectedness and Mental Health

Beavers are back: here’s what this might mean for the UK’s wild spaces

Joshua Larsen– Senior Lecturer in Water Science, University of Birmingham Annegret Larsen– Assistant Professor in Geography, Wageningen University and Research

The Eurasian beaver, once a common sight across Europe, had disappeared almost entirely by the end of the 16th century thanks to hunting and river modification for agriculture and engineering.

But beavers are making a comeback across the UK and several other countries. They have already been released into the wild in Scotland and within enclosed river sections in England. Now expanding the wild release of beavers across England is on the cards.

Ecosystem recovery, increased biodiversity, flood protection and improved water quality are some of the upsides of having beavers around. But reintroducing wild animals to the landscape is always going to involve trial and error, and it’s vital to understand the possible consequences – both good and bad.

The beaver is a gifted environmental engineer, able to create its own ecological niche – matching itself perfectly to its environment – by building dams. These dams are made from materials the beaver can carry or float – typically wood, stones and mud, but also fence posts, crops from nearby fields, satellite dishes and old kids’ toys.

The dam creates a peaceful, watery home for beaver families to sleep, eat and avoid predators. And the effects of dam building ripple outwards, with the potential to transform entire ecosystems.

Beaver dam of branches with deep river on one side and trickle of water in river bed the other side.
Beaver dam, Switzerland. Josh Larsen

Our review of beaver impacts considers evidence from across Europe and North America, where wild beaver populations have been expanding since around the 1950s.


There is clear evidence that beaver dams increase water storage in river landscapes through creating more ponds and wetlands, as well as raising groundwater levels. This could help rivers – and their inhabitants – handle ever more common weather extremes like floods and droughts.

If you observe beaver dams in the wild, water often comes very close to the top of their dams, suggesting they might not be much help in a flood. Nonetheless, some studies are finding that beaver dams can reduce flood peaks, likely because they divert water onto floodplains and slow downstream flow. However, we don’t know whether beaver dams reliably reduce floods of different sizes, and it would be unwise to assume they’re always capable of protecting downstream structures.

The good news is that it seems all the extra water dams store could help supplement rivers during dry periods and act as critical refuges for fish, amphibians, insects and birds during droughts.


Beaver dams increase the time it takes for things carried by rivers to move downstream. In some cases, this can help slow the spread of pollutants like nitrates and phosphates, commonly used in fertilisers, which can harm fish and damage water quality.

River water collects in deep pool behind beaver dam of branches.
Beaver dam in Switzerland. Annegret Larsen

Beavers’ impact on phosphates is unclear, with just as many studies finding phosphorus concentrations increasing downstream of beaver dams as those finding a decrease or no change. But beavers seem especially skilled at removing nitrate: a welcome skill, since high concentrations of nitrates in drinking water could endanger infant health.

Recovering diversity

All that water storage means beavers create a wonderful mosaic of still-, slow- and fast-moving watery habitats. In particular, they increase the biodiversity of river valleys, for example helping macro-invertebrates like worms and snails – key to healthy food chains – to thrive.

Beavers’ departure can leave anything from fens or peatlands to wet floodplain forests to drier grassland meadows developing in their wake. This gives beavers an important role in rewilding efforts.

A tree gnawed by beavers
Beavers leave their mark on the local landscape. Fietzfotos/Pixabay

But nuance is key here. Evidence of beaver dam impacts on fish populations and river valley vegetation, for example, is very mixed. Because they are such great agents of disturbance, beavers promote plants that germinate quickly, like woody shrubs and grasses.

While this can reduce forest cover and help some invasive plants, given time it can also help create valleys with a far richer mosaic of plant life. So although beaver presence is likely to bring benefits, more research is needed to get clearer on precisely how beavers change ecosystems.

Net zero carbon

Beavers are great at trapping carbon by storing organic matter like plant detritus in slow-flowing ponds. However, this also means beaver ponds can be sources of greenhouse gases, like CO₂ and methane, that contribute to the greenhouse effect. This led one author to wonder “whether the beaver is aware the greenhouse effect will reduce demand for fur coats”.

Can beavers still be helpful in achieving net zero carbon? The short-term answer is probably yes, since more carbon seems to be trapped than released by beaver activities.

A beaver dam constructed from maize in a river next to field of crops
Beaver dams, like this one made of maize, can help trap carbon. Gerhard Schwab

However, long-term outcomes are less clear, since the amount of carbon that beavers keep in the ground depends on how willing they are to hang around in a river valley – and how willing we are to let them. A clearer understanding of where beavers fit within the carbon cycle of river systems is needed if we are to make best use of their carbon capture skills.


Beavers are reentering landscapes under human dominance, the same thing that originally drove them from vast swathes of European river systems.

In the UK, this means they’ll lack natural predators and may be in competition with cows and sheep for food: possibly resulting in unsteady wild population trajectories.

Although good data on long-term beaver activity is available from Sweden, Norway and Switzerland, our different climate and landscapes mean it’s hard to make a straightforward comparison.

Beavers’ use in rewilding can be incredibly cost-effective, as dam construction and the biodiversity benefits that flow from it is done largely for free. But we need to be tolerant of uncertainty in where and when they choose to do their work.

Working with wild animals – who probably don’t share our priorities – is always an unpredictable process. The expansion of beavers into the wild has a bright future so long as we can manage expectations of people who own and use beaver-inhabited land.