Me, myself and nature

The biodiversity stripes I shared recently have been very popular. This follow-up post shares another set of stripes that help show why the human-…

Me, myself and nature

We studied 40,000 pieces of litter to find out where it all comes from – here’s what we discovered

  1. Thomas Stanton– Loughborough University Doctoral Prize Fellow, Loughborough University
  2. Antonia Law– Lecturer in Physical Geography, Keele University
  3. Guaduneth Chico– Lecturer in Environmental Sciences and GIS, Nottingham Trent University
  4. Matthew Johnson– Associate Professor, Department of Geography, University of Nottingham

Litter is perhaps the most tangible of all environmental problems. And it’s not just a disrespectful few who are responsible for it. Litter, defined in its broadest terms, includes any solid material present in the environment that was made or processed by people. It may have arrived there from an accidental spillage, as debris washed ashore, or because of the irresponsible management of industrial waste.

How some types of litter enter and travel through the environment cannot be traced. Litter breaks down beyond recognition, identifying marks such as branding wear away and rivers can transport it far from where it originated. But some litter has clear sources and pathways, discernible from its function and packaging labels, from which the brand that made the item can be easily identified.

The community interest company Planet Patrol created an app for people to record the litter they find and remove. We used it to map the location, materials, type and, where possible, brands of 43,187 items of litter collected across the UK in 2020. Our research was recently published in the Journal of Hazardous Materials.

Two maps of the UK depicting total app entries and total litter found by region.
App users submitted the litter they found throughout the UK. Stanton et al. (2022), Author provided

Plastic was the most common material recorded, accounting for 63.1% of all items. Metal was second (14.3%), followed by composite materials (pieces of litter made from more than one material, like Tetrapak cartons) at 11.6%. Bottles, lids, straws and other items from the drinks industry made up 33.6% of the total, of which metal cans were the most common.

Our citizen scientists identified brands for 16,751 items (38.8% of the total), with 50% of these belonging to just ten brands. The Coca-Cola Company was the most frequently identified brand (11.9% of branded litter), followed by Anheuser-Busch InBev (7.4%) and PepsiCo (6.9%). The top three brands were all drinks manufacturers.

A Sankey diagram showing how brands, parent companies and materials comprise total litter found.
Despite taking up most space in the statements of packaging manufacturers, plastic comprised a third of total litter found. Stanton et al. (2022), Author provided

Plastic policies

Surprisingly, our findings do not vindicate one of the EU’s most important orders on litter: the 2019 Single-Use Plastics Directive. This identified the top ten types of plastic litter based on beach surveys around Europe, and legislated to reduce their production and sale in the EU while the UK was still a member.

These ten items, which include cotton buds, plastic bags and plastic bottles, were not all common in our results, which came from sampling inland areas as well as some beaches. Though this directive applies to the whole of the EU, we suspect its focus on coastal environments alone does not accurately reflect the nature of most litter found across Europe.

Two disposable coffee cups immersed in sand on a beach.
Common litter on beaches may not represent what’s typically found elsewhere. Henk van Dijk/Shutterstock

Throughout the 2020s, the UK government and its devolved powers will introduce or reform legislation to tackle litter. These include a plastic tax (introduced in April 2022), a tax on the production of plastic packaging containing less than 30% recycled plastic, a deposit return scheme for drink containers (limited to plastic containers only in England) and reforms which will make packaging producers pay for action including litter picking and education campaigns. Over the same decade, the top ten companies identified by our study plan to change the materials they use in their packaging.

Our analysis of these corporate and legislative policies concluded that they disproportionately favour solutions based on recycling, with little consideration of how to reduce waste and allow people to reuse items. This approach fails to address plastic pollution’s root cause: selling things people don’t really need.

Should we name (and shame)?

Since most litter in the environment cannot be traced back to its origins, naming the people and organisations responsible may seem futile. But litter that can be linked with an industry or a company is some of the easiest to address. This is particularly true for packaging, which made up 59.1% of the items logged in our study.

Given how common this type of waste appears to be, expanding opportunities for people to refill containers with goods (where appropriate), removing or reducing the need for new packaging as zero-waste shops do, is a good idea. This will require collaboration between companies, industries and governments. Small-scale efforts to achieve this are underway, with Wales pledging to become the first refill nation (where people can easily refill water bottles, making bottled water obsolete), some supermarkets introducing or trialling refill aisles and The Coca-Cola Company’s various small-scale efforts to allow consumers to refill bottles with beverages, most notably in Latin America.

A person fills a mason jar with red lentils.
Zero-waste shops allow customers to fill containers brought from home. Reshetnikov_art/Shutterstock

Making it easier for people to refill packaging would also reduce demand for raw packaging materials, lower transportation costs and emissions and reduce waste. It will also help people reckon with their own environmental footprints.

Tracing and curbing litter requires foresight and collaboration, which is currently lacking among companies that profit from the waste-generating consumption of single-use products, and the legislators that fail to properly govern it. Naming them is the start of holding them accountable.


Drought: why some UK trees are losing their leaves in August

Stuart Thompson– Senior Lecturer in Plant Biochemistry, University of Westminster

Leaf fall in London, July 2022. Matthew Chattle / Alamy

Britain is suffering its worst drought since the 1970s, with dry weather expected until October. Many parks and lawns are now more straw than grass, but some trees and other plants have responded in a more surprising way: by losing their leaves.

It is likely that this exceptionally dry weather is due to climate change. But are trees turning brown or dropping their leaves because they have lost track of the seasons, and behaving as if it is autumn?

Leaf fall is a carefully controlled process in which the junction between the leaf and the stem is precisely dissolved without damaging surrounding parts of the plant. Given this, you might think that it could only happen now if the trees and other plants are confused.

But this is not the case. Instead, it is an emergency response to protect the plant from dehydration.

The reason becomes clear if we think about what leaves do: they are solar panels, collecting sunlight and capturing its energy through the process of photosynthesis. Carbon dioxide is one of the key ingredients in this process and plants obtain it from the atmosphere, initially dissolving it in water coating the inside surfaces of each leaf.

To give the leaf the largest possible area to capture carbon dioxide, these interiors are folded and folded until they are typically 20 times the area of the leaf’s outside surface. This is good for harvesting carbon dioxide, but means water can be lost through evaporation across all of this huge area.

As much as 99% of water taken up by plants just passes through them and evaporates into the air in this way. Rain forests are rain forests because the trees release so much water vapour that they change the climate around them. Some large trees take up and evaporate a metric tonne of water in a day.

Leaves left useless

This is fine if water is plentiful, but what if it is not? In a drought, plants initially close the pores in their leaves that allow carbon dioxide in and through which water escapes. This reduces water loss but also slows or stops photosynthesis, since the supply of carbon dioxide is cut off.

Furthermore, closing the pores traps the oxygen produced as a by-product of photosynthesis inside the leaf. Oxygen is necessary for most living things, but is an aggressive and destructive substance which damages leaves if it builds up. The light energy a leaf captures can also become dangerous if it cannot be used to convert carbon dioxide to sugars. Leaves are left useless and accumulate damage when their supply of carbon dioxide is cut off to save water.

Large tree, turning slightly brown
Early autumn colours in Richmond Park, London, August 2022. Malcolm Park / Alamy

Lack of water can also do more fundamental harm. Leaves need a continuous supply to replace the water lost during photosynthesis and to remain hydrated. Otherwise they will slowly dry out even when their pores are closed.

Water molecules stick to one another, which is why pond skaters can run across a pond without breaking the surface. Plants use this phenomenon on a much larger scale to transport water up to their leaves in narrow, water-filled tubes. As water evaporates from the leaves, each water molecule in the tube pulls on the next, drawing the whole column of water upwards without the plant having to do any work.

An elegant trick, but as it gets harder and harder to pull water out of dry soil, the tension in the water can become so great that these columns break, blocking the tubes with bubbles and preventing water reaching the leaves for long periods. Shedding leaves reduces this risk too.

Not all species lose their leaves to cope with lack of water, but most will have had to reduce or stop photosynthesis in one way or another. Without photosynthesis, ecosystems will shrink. Less photosynthesis means less plant growth and therefore less food for herbivores – and, in turn, fewer herbivores for carnivores to feed on. It will also affect UK food production unless water is diverted to farms to protect crops, a particular concern at present because of disruptions to grain supplies due to the war in Ukraine.

Although drought-induced leaf fall may not be due to a jumbling of the seasons, climate change is disrupting ecosystems in other ways. Different species use different cues to calibrate their annual cycles and as the world warms, organisms are slipping out of sync as their individual interpretations of changing temperatures and weather patterns shift.

This can easily disturb delicate networks of interactions and interdependencies. For example, plants may produce flowers at the wrong time for bees to pollinate them. Disruption of patterns of bird migration may mean that fruit-bearing plants have no way to spread their seeds. If they set off at the wrong time, migratory species may arrive at their destination to find they have missed a key food source, or that it isn’t available yet.

This drought seems likely to be a taste of more extreme and chaotic weather patterns to come, in which we and the living world will frequently have to scramble for solutions in the face of new and unpredictable climatic conditions.


Castlefield Viaduct: Manchester’s new park in the sky could transform the city – but who will benefit?

Ian Mell– Reader in Environmental & Landscape Planning, University of Manchester

An urban park as a slice of history. PA Images | Alamy

In July 2022, Manchester welcomed the newest addition to its roster of urban parks. Owned by the National Trust, the Castlefield Viaduct is a Grade II-listed, 19th-century railway bridge that has been redevelopped into a new 330m-long sky park.

The project is part of a wider repurposing of brownfield and former industrial space in Manchester with several other projects promoting the city as a go-to place for innovative urban development in housing and green and open space. Under construction, in particular, is Victoria North, a new neighbourhood of 15,000 new homes across a 155-hectare site in the north of the city. This includes City River Park, a huge new “recreational corridor”, according to the proposals, along the River Irk.

For now, the National Trust is operating Castlefield Viaduct as a 12-month trial. Entry is free but ticketed and limited to 100 visitors per day on allocated one-hour slots each afternoon. Due to the extensive publicity campaign, high demand has led to the National Trust website crashing.

Colourful plants in a plant bed along a walkway.
3,000 plant species greet visitors on the new walkway. Ian Mell, Author provided

The idea behind the trail is to generate political and financial support to create a longer park extending westwards (the current layout only covers a proportion of the total viaduct area) and make it permanent.

Initial reactions to the Castlefield Viaduct have been positive. Local charity Castlefield Forum, which is set to have its own community plot on the bridge, has launched a podcast to tell the area’s stories.

Access to green and open space is urgently needed in central Manchester. However, as my research on access to nature and regeneration shows, there is no guarantee that simply having green space makes people use it. Location, access routes and amenities all influence usage. Exactly who stands to benefit from a project like Castlefield Viaduct becoming a permanent feature of the city skyline is a crucial question.

Steel beams cross over a planted walkway on a bridge platform.
The Castlefield Viaduct brings a new, industrial aesthetic to Manchester’s green spaces. Ian Mell, Author provided

A Victorian structure revisited

Built in 1892, the bridge was left derelict after 1969, when Manchester Central Station, now the Manchester Central Convention Complex, was taken out of service. Repurposing an abandoned site with little access, socio-economic worth or ecological value into a public park is a sign that Manchester city council, the landowner of the viaduct, is willing to test new approaches to urban greening.

Initial designs for the site were drawn up by London studio Twelve Architects. Founding director Matt Cartwright explained in 2021 that the brief included creating “moments of joy”. On a recent visit, I found the site is divided into three distinct zones linking the viaduct’s past, present and future journeys.

Seats, planted beds and a light coloured pathway on a bridge.
Motifs of the bridge’s structure are repeated in the landscaping of the park. Ian Mell, Author provided

The opening section draws on the railway motifs of trellis architecture to guide people into the site. The second introduces the 3,000 planted species – from cotton grass and ferns to fennel, Broom and fleabane – in a range of planters, highlighting the biodiversity of the local environment.

The third, meanwhile, which you can currently see, but not acccess, from the visitors centre, offers views on to where the site may go physically and conceptually. These various spaces blend with the sound of the passing trams. You are keenly aware of being in both a park and in a layer of the city’s history. The linear nature of the site underscores the notion of travel between the zones – as a visitor, you walk there and back again.

How Mancunians need more green

Castlefield is thus doted with a unique conceptual motif and a novel industrial aesthetic, as compared to other parks in Manchester. It remains to be seen, though, whether the design and the fact that it is located in an area of largely privately rented and owned flats will attract locals or serve primarily as a tourist attraction for visitors.

When the 606 linear park opened in Chicago in 2015, local residents reportedly expressed fears they would be priced out of their neighbourhoods. Reports in 2020 revealed that the park had indeed triggered luxury developments and long-term local residents being displaced. Research shows how similar developments, including New York’s High Line, can lead to what economists have dubbed eco-gentrification.

Research has also shown how much need there is for green space in Manchester. The city centre currently has very few public green spaces, and even fewer that provide play facilities or access to nature. According to Friends of the Earth, over 73% people across Manchester have poor or limited access to a personal garden or a communal green space. Covid lockdowns highlighted how significant this lack of access to green space is, especially for those with families.

The redevelopment of the Castlefield Viaduct presents an interesting conundrum for Manchester and other UK cities. High-quality and potentially exclusive locations that are inaccessible can nonetheless act as a catalyst for green-space investment linked to regeneration programmes like Grosvenor’s Living Cities. This strategy provides increased certainty for investors but primarily serves specific communities, that is, those who can afford market-rate apartments.

We also need look beyond the financing of high-end projects towards a more locally attuned approach to green space provision. Urban planning expert Meredith Whitten has shown how this would focus on local provision for meeting people’s everyday needs to interact with nature, play outside and live in a biodiverse landscape.

This requires sufficient public funding to be allocated to local government to support capital and revenue spend on public parks –- something not seen in the UK over the last 12 years.

By drawing on the industrial heritage of the city, Castlefield Viaduct makes strong links to its fabled Cottonopolis heritage. The park also sets out a bold statement of intent, that redundant spaces in Manchester can be meaningful, accessible and interactive. Of course, integrating industrial chic with urban regeneration is nothing new. But it is new in Manchester. This could be the start of something beautiful.


Why turning old city bridges into new urban parks is such a great idea

Nick Dunn– Professor of Urban Design, Lancaster University

Castlefield Viaduct in 2020 as work on the newly opened sky park got underway. PA Images | Alamy

The recent opening of the Castlefield Viaduct Sky Park in Manchester, UK, has brought fresh attention to the growing number of projects that reuse urban infrastructures to create linear parks.

When the Promenade Plantée opened in 1993 on top of an abandoned railway viaduct in Paris, it was reportedly the first of its kind. It provided local residents a green escape, ten metres above the tarmac of the street below, and a beautiful, three-mile meander from the Bois de Vincennes to Bastille. The opening of New York’s fabled High Line, in 2009, further cemented this type of urban regeneration as something for cities to aim for.

Post-pandemic, finding innovative ways to eke out accessible green spaces in the urban environment is more urgent than ever. Doing so provides health and environmental benefits alongside economic ones, by promoting biodiversity, mitigating air pollution, and in some (though not all) cases, reducing the heat island effect.

Plantlife spills over the edges of an elevated railway above a busy intersection
The High Line in Manhattan. Krzysztof Stefaniak | Shutterstock

How a local approach to high lines is needed

Since the 2000s, city planners across the world have tried to replicate what has been called “the High Line effect”. Built on top of a disused stretch of elevated freight rail line in western Manhattan, the High Line garnered considerable press and media coverage from the outset. It has been rightly championed as a success story, attracting eight million visitors a year and fostering new economic activity.

But not everywhere else is wealthy Manhattan. By reinvigorating the industrial heritage and cultural identity of a place, this approach can increase tourism which can have mixed results.

Recent research has shown that without policies in place to ensure that lower-income local communities can enjoy the benefits of newly greened spaces, including health benefits, these projects can actually exacerbate inequality by raising property values and causing the displacement of long-term residents who can’t afford to stay. Urban planning experts talk about green gentrification, as has been noted in the case of the 606 linear park in Chicago, among others.

Instead of simply trying to copy what has been done elsewhere, this type of regeneration is best done when attuned to the local heritage. As Historic England has emphasised, the best way to steward heritage sites and the historic environment is by keeping people’s wellbeing in mind. In particular, it’s about giving local people a voice, a place to be active and a sense of belonging.

Signposts at a junction in a pedestrianised green space.
The 606 elevated trail in Chicago. Carlos Yudica | Shutterstock

Why reusing existing structures is best

Adapting existing infrastructure is an integral part of rethinking the city in an era of climate emergency. The era of grand visions for public parks is largely over, as most cities are already full. Both spatially and economically, forming large green spaces from scratch is not possible.

Reworking old railway lines and bridges into parks, conversely, contributes to a wider strategy of adaptive reuse and what designers term urban acupuncture. Since the 1960s, pocket parks have been created out of small, hidden or overlooked bits of land between existing buildings.

A pond set between planted beds in an elevated walkway.
The Promenade Plantée in Paris. Joao Paulo V Tinoco | Shutterstock

The hyper-local nature of this type of urban greening makes it easier for residents to access and benefit from these spaces. As pressure increases on how we use resources and keep carbon in the ground wherever possible, enabling everyone to have access to green space for health reasons is critical.

This can be challenging in those cities where a large proportion of residents do not have access to private gardens. Capitalising on a city’s vertical space – as elevated walkways do – is a huge advantage in high-density cities where significant pressure on ground-level space exists. What’s more, the structures being turned into parks are usually found in those parts of a city that are post-industrial and in need of regeneration.

In terms of environmental impact, these parks have great potential. Each year the High Line, for example, sequesters over 1.3 tons of atmospheric carbon and its tree canopies collect over 24,340 gallons of stormwater.

An overhead shot of an elevated park in a city centre.
The Seoullo 7017 Skygarden. Keitma | Shutterstock

Further, by reusing existing industrial structures rather than demolishing and replacing them, embodied carbon can be kept where it is. Research on the Seoullo 7017 Skygarden in Seoul, a linear park built atop a disused highway overpass which cuts across the city’s main rail station, has shown that rewilding and landscaping urban infrastructures is more cost effective and less environmentally impactful than completely replacing them.

There is growing evidence of how important biodiversity in cities is, not just during daylight hours but at night too. Reused infrastructure projects can play an important role in providing ecological corridors across cities for nocturnal creatures. Supporting both human and non-human life in this way is a valuable step towards improving the sustainability and resilience of places.

Linear parks thus weave nature into the flow of a city. They support wildlife. They encourage sustainable transport and physical activity (walking, biking, jogging). They are, as landscape architect Diana Balmori puts it in her 2010 book, A Landscape Manifesto, dynamic spaces: “not peaceful retreats but ways”.


In defence of pigeons

Steve Portugal– Reader in Animal Biology and Physiology, Royal Holloway University of London

Pigeons are widely treated with contempt by the public. Fercast/Shutterstock

If you ask people why they like their favourite animal, they will tell you about the incredible things the creature can do, its relatable characteristics or its interesting looks. Few would be likely to cite the pigeon as theirs. Many people think of them as vermin rather than wildlife.

People’s utter disdain for feral pigeons breaks my heart. Sit in a park at lunchtime, anywhere in the world, and you’re almost certain to witness people lashing out at pigeons.

I see people stamping their feet and kicking as the birds weave in and out of their legs to snaffle leftover crumbs. But few people stop to think why there are pigeons under the bench they’re sitting on. We brought them into our cities, yet so many despise them. It hasn’t always been this way; we have a rich and long relationship with the humble pigeon.

Feral pigeons are the descendants of wild rock doves. We domesticated them centuries ago, for food and their supreme navigation skills. They thrive in our cities because our tall buildings and window ledges mimic their natural home; caves and cliffs. Our waste provides ample food.

People are enthusiastic about homing pigeons but there isn’t much difference between homing pigeons and feral pigeons. It just depends on whether they live in someone’s loft as a captive pigeon or the local town square.

Who are you calling bird-brained?

The homing abilities of pigeons are legendary. We are still learning about how amazing these birds are. They can do basic maths, on a par with monkeys, and can distinguish real words from made up ones.

Homing pigeons can find their way using smell, landmarksEarth’s magnetic field and infrasound (sound waves with a frequency too low for humans to hear). They can also follow each other and are able to learn routes from one another. Feral pigeons generally mate for life, and they are very attentive parents. The adults produce a crop milk, which they gently drip-feed to their chicks.

Our fascination with their homing abilities continues today, with tens of thousands of pigeon races around the world every year. Pedigree winners sell for over £1 million.

Pigeons are found in large numbers in cities. PauliusPeleckis/Shutterstock

Image problems

We have such disdain for the pigeons living amongst us in our towns and cities. But not so long ago we were fascinated with these creatures. In the mid 1800s we started to appreciate pigeons for their good looks. During this period, many new breeds emerged, including fantails, Jacobins, tumblers and barbs.

Tumbler pigeon. Morrowind/Shutterstock

Their exaggerated features attracted the attention of Charles Darwin. He was a pigeon aficionado and used this dramatic example of diversity within a species to convey his ideas about natural selection in The Origin of Species. It is almost as if we have seen feral pigeons too often to appreciate their rainbow throat feathers and cute, plump bodies. These features would be prized in a rare species.

Warrior birds

Feral pigeons are true survivors. Having spent many hours observing pigeons in St James Park in London, I have seen them caked in oil, milk and human vomit. I have watched pigeons with one foot missing, both feet missing, with only one leg, or trapped in bits of litter. Yet they soldier on. The normal outpouring of sympathy towards animals in distress is absent for feral pigeons. Many people have told me that far from inspiring sympathy, pigeons’ battle scars only add to their dislike: the birds look “messy”. Feral pigeons are thought to be prone to losing toes and feet because human hair and netting tangles around them, cutting off the blood supply. They can also get their feet stuck in chewing gum. Our litter harms pigeons and then we treat them with contempt for the way it makes them look.

Pigeons are a common sight in cities. Ercan Mercankaya/Shutterstock

Pigeons are some of the most decorated animals in history. No less than 32 pigeons have won the prestigious Dickin Medal, the animal equivalent of the Victoria Cross. Homing pigeons were used intensively during both the first and second world wars, to deliver vital messages between battalions and fly with cameras on for reconnaissance missions. Perhaps the most famous war pigeon is Cher Ami, who in 1918 was awarded the French Croix de guerre medal, for delivering messages from an encircled battalion under heavy fire. Cher Ami was shot through the breast, blinded in one eye, and his right leg was only hanging on by a tendon by the time he delivered his messages.

There is not much difference between homing pigeons and feral pigeons. stockphoto mania/Shutterstock

For many people, feral pigeons are some of the only wildlife they interact with on a regular basis. These interesting birds live right on our doorsteps. Next time you’re outdoors, give pigeons 30 seconds of your time. Watch them. Witness their intricate social interactions and see the tender moments between pairs as they preen each other and bring nesting material as gifts. However, if you really don’t want them around during your lunchbreak the best advice is: be a less messy eater.


Thousands more species at risk of extinction than currently recorded, suggests new study

Lilly P. Harvey– PhD Researcher, Environmental Science, Nottingham Trent University

Amphibian species are particularly at risk. elementals / shutterstock

New research suggests the extinction crisis may be even worse than we thought. More than half of species that have so far evaded any official conservation assessment are threatened with extinction, according to predictions by researchers from the Norwegian University of Science and Technology.

Conservation resources are limited and it is not feasible or logical to protect every square kilometre of land and sea. So to mitigate the rapid loss of biodiversity, where should our conservation resources go? To answer this question we first need to know which species to protect.

The International Union for Conservation of Nature coordinates a network of scientists who have assessed biological information available for all sorts of species worldwide for more than 50 years, publishing their findings in the Red List of Threatened Species. Its goal has been to identify species that need protection with an assigned conservation category of extinction risk.

It’s the Red List that confirmed tigers are officially endangered, for instance, or that giant panda populations have recovered enough to move from endangered to merely vulnerable.

However, while species like pandas and tigers are well studied, researchers don’t know enough about some species to properly assess their conservation status. These “data deficient” species make up around 17% of the nearly 150,000 species currently assessed.

When analysing conservation data it is common for researchers to remove or underestimate assumptions of threat for these species, in order to control for unknown variations or misjudgements. Now, these researchers in Norway have tried to shed light on the black hole of unknown extinction risk by designing a machine learning model that predicts the threat of extinction for these data deficient species.

Machine learning for extinction assessment

When thinking of artificial intelligence and machine learning it is easy to imagine robots, computer-simulations and facial recognition. In reality, at least in ecological science, machine learning is simply an analytical tool used to run thousands of calculations to best represent the real-world data we have.

In this case, the Norwegian researchers simplified the Red List extinction categories into a “binary classifier” model to predict a probability of whether data deficient species are likely “threatened” or “not threatened” by extinction. The model algorithm has “learned” from mathematical patterns found in biological and bioclimatic data of those species with an already assigned conservation category on the Red List.

Giant Panda webpage on IUCN Red List
The Red List assigns each species in one of seven conservation categories, or tags them as ‘not evaluated’ or ‘data deficient’. IUCN Red List

They found more than half (56%) of the data deficient species are predicted to be threatened, which is double the 28% of total species currently evaluated as threatened in Red List. This reinforces the concern that data deficient species are not only under-researched, but are at risk of being lost forever.

On land, these likely threatened terrestrial species are found across all continents, but live in small geographically restricted areas. This finding supports previous research with similar conclusions that species with small range sizes are particularly vulnerable to anthropogenic habitat degradation, such as deforestation or urbanisation.

At risk amphibians

Amphibians are the most at-risk group, with 85% of those data deficient species predicted as threatened (compared to 41% of those currently evaluated on the Red List). Amphibians are already a poster-child for the extinction crisis and are a key indicator for ecological health, as they depend on both land and water. We don’t know enough about what causes such catastrophic extinction of amphibians, and I am part of a science initiative trying to address the problem.

Black and yellow toad on green leaf
Dozens of harlequin toad species in Central and South America have been discovered and almost all are already critically endangered or extinct in only a few decades. goran_safarek / shutterstock

It’s a slightly different, but still tragic, story at sea. Data deficient marine species that are predicted to be facing extinction are concentrated along coasts, particularly in south-eastern Asia, the eastern Atlantic coastline and in the Mediterranean. When data deficient species are combined with fully-assessed species on the Red List, there is a 20% increase in the probability of extinction along the eastern coastlines of tropical Latin America.

What this means for global conservation

Two world maps
How data deficient species change conservation priorities: percent change in probability of a species being threatened by extinction once data deficient species are factored in. (a = marine species; b = non-marine) Borgelt et al / Communications Biology

Though it is likely that the need for conservation has actually been underestimated worldwide these probability predictions are highly variable across different areas and groups of species, so don’t be fooled into overgeneralising these findings. But these broad results do highlight why it is so important to further investigate data deficient species.

The use of machine learning tools can be a time-and-cost-effective way to enhance the Red List and help overcome the challenging decision of where and what to protect, aiding targeted conservation action and expanding protected areas in these black holes of biodiversity.


Houseplants don’t just look nice – they can also give your mental health a boost

Lauriane Suyin Chalmin-Pui– Wellbeing Postdoctoral Fellow with the Royal Horticultural Society, University of Sheffield

Houseplants can be an essential link to nature – especially for those without access to a garden. Syda Productions/ Shutterstock

For those of us without access to outside green space, houseplants are a stylish and affordable way of getting a nature fix. Alongside looking nice, indoor plants actually have several other perks – the biggest benefit of which could be improving your mental health. And the good news is you don’t need to be a self-professed “plant parent” to experience these benefits either.

One in eight UK households don’t have access to any kind of garden. Young people and those from minority ethnic backgrounds are among those least likely to have a garden.

Not having access to nature can have a number of effects on our health. It’s been linked to symptoms of depression and anxiety, as well as other health conditions, such as asthma, cardiovascular disease, and poor immune function. For many of us, houseplants are an essential link to nature.

While there’s not yet a robust body of research on the mental health benefits of houseplants specifically, plenty of studies have shown how beneficial green space and gardening are for mental health. For instance, one study found that people who garden daily have better wellbeing and lower stress levels compared to those who don’t.

Gardening also reduces symptoms of depression and anxiety and increases positive emotions to the same extent as biking, walking and eating out. Many of these outcomes are likely to be true of houseplants too.

A recent review of 42 studies demonstrates that even just being in the presence of indoor plants can improve mental and physical health. These experiments compared participants doing various activities in rooms with or without plants.

The presence of plants saw better performances on cognitive tasks involving focus, sorting or memory recall, greater pain tolerance when holding hands in ice cold water, and lower levels of physiological stress. Interestingly, the aesthetic appearance of plants is important too, with separate research showing that people tend to react more positively to lush, green plants with rounded and denser foliage.

But most of these studies are centred around the mere presence of plants. From research on the benefits of gardening, we can assume that caring for houseplants will bring out many more emotional benefits – such as pride, social connectionsatisfactionfascinationmental resilience in times of stress, and may even help you heal from past trauma.

Good for you

There are plenty of other reasons owning houseplants is beneficial for you.

Plants can remove pollutants such as carbon dioxide, nitrogen dioxide (from nearby traffic), fine particles (from dust) and volatile organic compounds (from air fresheners, cooking and cleaning). For people indoors for the majority of the day, indoor air quality is hugely important.

High concentrations of carbon dioxide can reduce cognitive performance (such as concentration and memory recall) while prolonged exposure to other indoor pollutants can cause long-term health problems – ranging from minor eye or throat irritations to respiratory problems and cancer.

But removing a meaningful quantity of indoor pollutants would require a lot of plants in a very bright room – something unrealistic for most people. If you do want to give it a try, plants with a high leaf area – such as an India rubber tree (Ficus elastic) or devil’s ivy (Epipremnum aureum) are your best bet.

A young woman wearing gardening gloves uses a spray bottle to water her houseplant.
Houseplants can be good for other aspects of your health, too. antoniodiaz/ Shutterstock

In theory, plants can also help increase indoor air humidity. Most of our buildings are too dry. Keeping humidity in an optimal range can prevent the spread of viruses, fungal growth, as well as eye, skin and nose dryness. Though dependent on other conditions in the room like size, light, and airflow, some of the best plants for increasing humidity are English ivy (Hedera helix), Devil’s ivy (Epipremnum aureum) and Peace Lily (Spathiphyllum).

Lifelong learning

You don’t need a green thumb to enjoy success with houseplants. Gardening is all about learning through trial and error, and even the most seasoned gardeners make mistakes. Indeed, not all plants will thrive everywhere – and some may struggle through infestations, won’t adapt to light or water conditions, and die. Try not to get hung up on this setback. It’s always worth trying again, perhaps with a different species and armed with more botanical knowledge.

Each plant has different requirements, so look for plants that are suited to the conditions in your home. You may even want to find plants that actually thrive on neglect. Some of the best options for beginners are the spider plant (Chlorophytum comosum), the parlour palm (Chamaedorea elegans), and anything in the cactus and succulent families, such as the zebra cactus (Haworthia) or the jade plant (Crassula ovata).

Growing herbs is also a cheap and useful starting point for beginners. There are also apps out there that can help make it easier for you to care for your plants, by giving you advice, reminders and a forum to ask questions.

Owning houseplants can have a range of benefits for our health – especially mental health. It can also be a great hobby that always teaches you something new, encourages self-expression – choosing and caring for plants –, and gives you a tangible sense of fulfilment.


Seven reasons Nordic walking is better for you than the normal kind

Lindsay Bottoms– Reader in Exercise and Health Physiology, University of Hertfordshire

Nordic walking may be a great way to boost the benefits of your regular strolls. Jacek Chabraszewski/ Shutterstock

Have you ever noticed people out walking with poles even on flat surfaces and wondered why they are doing it? This is known as Nordic walking, which is a little bit like cross country skiing but without the snow.

Walking with poles was first developed in Scandinavia and came to central Europe about 20 years ago. For some reason, it has not become particularly popular even though it has many health benefits.

Here’s why – alongside a few good reasons to give Nordic walking a try.

1. You burn more calories

As far back as 1995, researchers noticed that Nordic walking burned more calories than regular walking did. In fact, they found it burned up to 18% more calories than ordinary walking did.

Numerous studies have confirmed these findings since – which is why it’s suggested that Nordic walking could be a great form of exercise for those looking to lose weight. One study from Italy even found that overweight people lost weight faster doing Nordic walking compared to ordinary walking.

While Nordic walking doesn’t burn more calories than other, more intense forms of exercise – such as running – it can be a great low-impact exercise option, or a way to boost the benefits of your regular daily walks.

2. It may reduce limb pain

Using poles while you walk can distribute your weight through the arms and torso, placing less strain on your back, knees and hips. In theory, this has the potential to improve back pain while walking.

However, research is mixed, with some studies showing Nordic walking can reduce lower back pain and impact on the knees, while others show it’s no more helpful than ordinary walking.

If you’re someone who suffers from lower back, hip or knee pain, Nordic walking could be helpful to you since it redistributes your weight somewhat. But it’s worth discussing with your doctor first before giving it a try, and stopping if your pain still persists even while using the poles.

3. Improves upper body strength

Nordic walking engages your arms and shoulders more than regular walking does, and that could improve your strength. Research has shown that Nordic walking can not only increase hand grip strength but also increases muscle activity in the shoulders.

Upper body strength – including how strong your grip is – is important for many of the things we do everyday, from carrying our shopping to filling up the kettle. Increasing muscle strength is also important to help prevent injury as it helps stabilise the joints and protects them when moving under impact like carrying heavy shopping bags.

Read more: How strong your grip is says a lot about your health

4. Increases core strength

Nordic walking also engages the core muscles (including those in the abdomen and your back) more than ordinary walking does.

Greater engagement of the core muscles will help strengthen them, which may in turn improve posture. Better core strength can also improve your balance as well as your ability to move.

5. Reduce risk of falling

Unfortunately as we get older we are more likely to trip and fall when we are walking. This is mainly because of a decrease in muscle strength, balance issues and problems with the way we walk.

Two elderly ladies wearing winter coats stroll down a woodland path using walking poles.
Nordic walking may improve balance. Alexey Smyshlyaev/ Shutterstock

The benefit of Nordic walking is that you are placing the poles into the ground at the same time as you’re using your legs. This improves balance and makes you less likely to fall.

In fact, one study even showed that people who followed a Nordic walking training programme for three weeks had improved balance – even when walking without poles. It’s no wonder Public Health England recommends Nordic walking for improving balance in older people.

6. Boosts cardiovascular health

Research shows that Nordic walking can improve cardiovascular fitness in as little as four weeks.

Another study on obese women also showed Nordic walking was able to improve blood pressure, though only to a similar extent as ordinary walking. In addition, Nordic walking has been shown in postmenopausal women to improve resting blood sugar levels, which is important in preventing diabetes as well as improving cholesterol levels in the blood.

7. You can walk faster

Nordic walking can help you get where you want to be faster than ordinary walking can. In fact, a review showed Nordic walking increased average walking speed by up to 25% compared to ordinary walking. As a consequence of walking faster, you can then burn more calories. So if you went for a 30-minute Nordic walk, you’d be able to walk further and burn more calories than you might on a regular walk.

There seem to be clear advantages to doing Nordic walking. It may especially be good for people who don’t like other types of exercise – such as running – but still want to do something of a higher intensity than brisk walking.


James Lovelock: the scientist-inventor who transformed our view of life on Earth

Mark Maslin– Professor of Earth System Science, UCL

James Lovelock outside his home laboratory. Homer Sykes/Alamy Stock Photo

James Lovelock, the maverick scientist and inventor, died surrounded by his family on July 27 2022 – his 103rd birthday. Jim led an extraordinary life. He is best known for his Gaia hypothesis, developed with the brilliant US biologist Lynn Margulis in the 1970s, which transformed the way we think of life on Earth.

Gaia challenged the orthodox view that life simply evolved and adapted to the ever-changing environment. Instead, Lovelock and Margulis argued that species not only competed but also cooperated to create the most favourable conditions for life.

Earth is a self-regulating system maintained by communities of living organisms, they claimed. These communities adjust oxygen and carbon dioxide levels in the atmosphere, salinity in the ocean and even the planet’s temperature to keep them within the acceptable bounds for life to thrive.

Just like Charles Darwin before him, Lovelock published his new, radical idea in a popular book, Gaia: A new look at life on Earth (1979). It was an instant hit that challenged mature researchers to reassess their science and encouraged new ones. As my friend and colleague Professor Richard Betts at the Met Office Hadley Centre put it:

He was a source of inspiration to me for my entire career, and in fact his first book on Gaia was a major reason why I chose to work on climate change and Earth system modelling.

Not only did the book challenge the classical Darwinism notion that life evolved and prospered through constant competition and dogged self-interest, it founded a whole new field: Earth system science. We Earth system scientists study all the interactions between the atmosphere, land, ocean, ice sheets and, of course, living things.

Lovelock also inspired the environmental movement by giving his ideas a spiritual overtone: Gaia was the goddess who personified the Earth in Greek mythology.

This antagonised many scientists, but created a lot of fruitful debate in the 1980s and 1990s. It is now generally accepted that organisms can enhance their local environment to make it more habitable. For example, forests can recycle half the moisture they receive, keeping the local climate mild and stabilising rainfall.

But the original Gaia hypothesis, that life regulates the environment so that the planet resembles an organism in its own right, is still treated with scepticism among most scientists. This is because no workable mechanism has been discovered to explain how the forces of natural selection, which operate on individual organisms, birthed the evolution of such planetary-scale homeostasis.

An aerial view of morning mist over a rainforest.
Organisms alter their environment to make it more favourable to life. Avigator Fortuner/Shutterstock

An independent scientist

There was much more to James Lovelock, who described himself as an “independent scientist since 1964”, because of the income generated from his invention of the electron capture detector while studying for a PhD in 1957.

This matchbox-sized device could measure tiny traces of toxic chemicals. It was essential in demonstrating that chlorofluorocarbons (CFCs) in the atmosphere, which originated in aerosols and refrigerators at the time, were destroying the ozone layer. It also showed that pesticide residues exist in the tissues of virtually all living creatures, from penguins in Antarctica to human breast milk.

A small device resembling a spindle with a white band in the middle.
The electron capture detector Lovelock invented for measuring air pollution. Science Museum LondonCC BY-SA

The money he earned from the electron capture detector gave him his freedom because, as he was fond of telling people, the best science comes from an unfettered mind – and he hated being directed. The detector was just the start of his inventing career and he filed more than 40 patents.

He also wrote over 200 scientific papers and many popular books expanding on the Gaia hypothesis. He was awarded scientific medals, international prizes and honorary doctorates by universities all around the world.

Dr Roger Highfield, the science director at the London Science Museum, summed Jim up perfectly:

Jim was a nonconformist who had a unique vantage point that came from being, as he put it, half-scientist and half-inventor. Endless ideas bubbled forth from this synergy between making and thinking. Although he is most associated with Gaia, he did an extraordinary range of research, from freezing hamsters to detecting life on Mars … He was more than happy to bristle a few feathers, whether by articulating his dislike of consensus views, formal education and committees, or by voicing his enthusiastic support for nuclear power.

Jim was deeply concerned by what he saw humanity doing to the planet. In his 1995 book The Ages of Gaia, he suggested that the warm periods between ice ages, like the current Holocene, are the fevered state of our planet. Because over the last two million years the Earth has shown a clear preference for a colder average global temperature, Jim understood global warming as humanity adding to this fever.

Jim did despair at humanity’s inability to look after the environment and much of his writing reflected this, particularly his book The Revenge of Gaia in 2006. But at the age of 99, he published Novacene: The Coming Age of Hyperintelligence (2019), an optimistic view which envisaged humanity creating artificially intelligent life forms that would, unlike us, understand the importance of other living things in maintaining a habitable planet.

His dwindling faith in humanity was replaced by trust in the logic and rationality of AI. He left us with hope that cyborgs would take over and save us from ourselves.