Biodiversity treaty: UN deal fails to address the root causes of nature’s destruction

  1. Bram Büscher-Professor of Geography, Environmental Management and Energy Studies, University of Johannesburg; Research Associate, Stellenbosch University; Professor of Sociology of Development and Change, Wageningen University
  2. Rosaleen Duffy-Professor of International Politics, University of Sheffield

A major biodiversity conference, recently concluded in Montreal, Canada, was billed as the event that will decide the “fate of the entire living world”. All well then that the meeting closed with what has been hailed as a “historic” breakthrough: a deal to protect 30% of all land and water on Earth by 2030.

How historic is this deal, really? Judging from the effect of protected areas and major environment meetings over the last few decades, we should not get our hopes up. In fact, this deal may force us to reconsider the usefulness of such meetings altogether.

If there is anything that defines the history of mainstream conservation it is the steady rise of protected areas, covering about 2% of the globe in the 1960s to around 17% now. This progress was incredibly difficult, and still created many ineffective “paper parks” where species are protected from hunting and other threats in name only. Worse, it bred human rights abuses and violence as people were excluded from land that was declared off-limits.

If it took 60 years to get to 17%, how realistic is a near-doubling of Earth’s protected areas over the next eight years? And how will it, despite the pact’s rhetoric of placing indigenous peoples at the centre of conservation, ensure that the violence of the past is not repeated?

All this is left to the more than 190 countries under the treaty to implement. Given the pressures of the extinction crisis and the increasing militarisation of conservation, we have little faith that history will now suddenly work out differently.

The real problem is non-negotiable

Even if 30% of Earth was protected, how effectively would it halt biodiversity loss? The proliferation of protected areas has happened at the same time as the extinction crisis has intensified. Perhaps, without these efforts, things could have been even worse for nature.

But an equally valid argument would be that area-based conservation has blinded many to the causes of Earth’s diminishing biodiversity: an expanding economic system that squeezes ecosystems by turning ever more habitat into urban sprawl or farmland, polluting the air and water with ever more toxins and heating the atmosphere with ever more greenhouse gas. These structural problems are mentioned but not actually addressed at global environmental meetings.

An aerial view of overlapping raised highway lanes.
No brakes on the pursuit of economic growth are expected. D.Kvasnetskyy/Shutterstock

Such meetings have become elaborate affairs eagerly organised by host states to reap tourist income and diplomatic goodwill. The idea is that conferences allow countries to negotiate global frameworks for tackling multiple, overlapping crises. Clearly, the planetary scale of environmental change requires cooperation at all levels.

After the second world war, multilateralism based on cooperation between states developed out of a sense of hopefulness and led to global conventions for addressing common challenges in many areas, including the environment. The 1987 Montreal protocol helped close the hole in the ozone layer. The CITES ivory ban has helped alleviate pressure on African elephants since 1989.

But that era is now over. UN summits have become little more than travelling circuses filled with desperate hopes but no real-world influence. Their meetings, announcements and deals are comprised of increasingly trivial language games, empty promises and non-decisions – many about the functioning of the convention itself. After every summit, small and sometimes major wins are celebrated as the breakthrough the world has been waiting for. But what have they actually done for the problems they are supposed to address?

Recent climate change summits have done very little to halt the growth in CO₂ emissions. And the Convention on Biological Diversity, which led this latest meeting in Montreal, was hobbled at its origin in Rio de Janeiro, Brazil in 1992. Here it was decided to split climate change and biodiversity across two conventions, fundamentally placing them on two different tracks when scientists argue that they need to be addressed together.

A polar bear standing on an ice floe surrounded by ocean.
The climate and biodiversity crises are intertwined. Chase Dekker/Shutterstock

It was also decided to render biodiversity, especially genes which might be valuable for industries such as pharmaceuticals, into “natural capital” that could be traded internationally. This enshrined capitalist ways of comprehending the environment at the outset of this process and entrenched a logic of turning nature into commodities. In short, the logic of the problem – the promotion of an ever-expanding economy – became the logic of the solution.

And so, there is a case to be made that international treaties actually deepen environmental destruction by making the problem seem soluble without changing a deeply unsustainable global economic system. They promote carbon offsets, biodiversity credits, no net loss (the idea that negative and positive consequences for biodiversity can be balanced as if on an accounting sheet) and other non-solutions. Fundamentally missing is a plan for an economy that accepts ecological limits to growth.

While more protected areas may alleviate the damage to some ecosystems and species in the coming years, their historical failure to prevent accelerating extinctions is not encouraging. We may still celebrate the international community coming to an agreement. But high expectations, big promises and negligible results have become the hallmark of UN environmental meetings.

We must therefore ask: have they become empty institutional hangovers of a lingering status quo that must be abandoned? Or is holding on to the fraying shreds of multilateralism worth the effort, even if they are becoming little more than extravagant witnesses to unfolding disaster?


Five ways you can help stop biodiversity loss in your area – and around the world

Kate Hiseman– Senior Lecturer Practitioner in Environment and Sustainability, Anglia Ruskin University

Biodiversity refers to the variety of life found on Earth and underpins the natural systems which grow our food, cleanse our air and water and regulate our climate. Human life cannot exist without it. But around one million animal and plant species are now threatened by extinction.

At the recent UN biodiversity conference (COP15) in Montreal, parties agreed on a set of targets for reversing global biodiversity loss by 2030. This includes protecting 30% of the Earth’s surface and reforming subsidies for farming and fishing. Meeting these targets will require coordination between governments and businesses.

Yet the pace at which legislation and policies take effect is exceeded by the global rate of biodiversity loss. Here are some of the most effective actions you can take to help reverse biodiversity loss and restore nature now.

1. Donate

The total area of protected land and sea in the UK increased from 27.6 million hectares in 2017 to 40.6 million hectares in 2022. Much of this area is managed by charities, legal bodies and local authorities.

These organisations, such as the RSPB and the Wildlife Trust, restore biodiversity by creating new habitats, improving existing ones and ensuring that wild areas are connected with forested corridors and reserves to allow species to roam. For example, the Wildlife Trust has reintroduced beavers to fenland in Kent, where wet grassland habitats are now thriving as a result.

But the funds available for nature conservation in the UK are often insufficientIndividuals and businesses can donate money to support the work of these organisations.

A beaver eating leaves in water.
Beavers have been reintroduced to good effect in Kent. WildMedia/Shutterstock

2. Volunteer

Many charitable organisations are dependent on volunteers to undertake administration and marketing, site management or to spread the message about the biodiversity crisis. With new digital ways of working, people could volunteer from their own home at suitable times. Experience is not necessary in most cases and volunteers often benefit from on the job training.

Volunteering can also have other benefits. Research has revealed spending just two hours in nature each week can benefit health and well-being.

3. Change what you eat

No one likes being lectured about their diet. But unsustainable farming methods, the expansion of agricultural land and our meat-based western diets all threaten biodiversity.

Converting natural habitats to agricultural land has resulted in one-quarter of all remaining mammal species being threatened with extinction. Research has also shown that agricultural intensification now means that more than half of European bird species are threatened or in decline.

To reverse biodiversity loss, we must change both what we eat and how much we consume.

The UK’s National Food Strategy and the Food and Land Use Coalition’s “Better Futures Report” recommend a diet that is less reliant on meat. The Food and Land Use Commission, for example, suggest that, from 2030, a sustainable adult male diet should consist of 14g of red meat per day, 29g of chicken and other poultry, 250g of dairy products, 500g of fruits and vegetables, 50g of nuts and 75g of soya bean and other legumes.

4. Nature-friendly gardens

Urbanisation is increasingly fragmenting natural habitats and, as such, species decline is highest in cities. As cities continue to grow it will become more important to have multiple approaches for biodiversity conservation.

Our gardens, although typically not spacious enough to maintain species diversity, can be important habitats in urban environments. Working with our neighbours, we can scale up our gardens by growing networks of flowers to help insects feed and planting trees for birds to nest in. This will increase biodiversity by creating a patchwork of habitats across a whole neighbourhood. Wildlife-friendly gardens can create corridors for a wide range of species and improve connectivity, provide shelter or nesting sites, maintain genetic diversity and increase the abundance of native plants even in the smallest spaces.

study in 2009 found that there were up to 28.7 million trees, 3.5 million ponds and at least 4.7 million bird nesting boxes in UK gardens. Nesting bird numbers can be increased if we know where trees can be planted for maximum effect. Networks of pollinating flowers across gardens could also help insects and butterflies feed.

A bee on a purple plant.
Networks of plants would allow insects to feed. David JC/Shutterstock

5. Indoor cats and responsible dog owners

Cats are natural predators and allowing your pet to roam freely around the neighbourhood means it – and all the other free-roaming pet cats out there – could be responsible for the deaths of millions of animals each year. Research in Australia revealed that by allowing cats to freely roam, predation on local prey per square kilometre in residential areas is 28–52 times larger than predation rates by feral cats in natural environments. Cats have caused such devastating impacts to Australian wildlife that cat predation is listed as a key threat to native wildlife within national legislation.

In the UK, cat ownership in the UK has increased by 13% on average each year over the past 40 years so that roughly 90% of the UK’s cats are now pets. This has correspondingly increased the threat to our native wildlife.

There are several ways we can reduce the impact of pet cats on biodiversity. Keeping a cat well fed reduces their need to hunt. Another option is to keep them indoors for parts of the day, during the night or entirely. The impact of pet cats on Australian wildlife has grown so severe that local authorities have introduced bylaws and curfews to contain cat predation.

Cats predominantly threaten biodiversity in urban areas. Yet the interaction between dogs and wildlife occurs more frequently in rural situations.

The issue here arises primarily as a result of predation and disease transmission. But dog faeces and urine fertilise soils with nutrients and can change the type of plants that grow in an area. This carries knock-on effects on a habitat’s structure. By picking up dog faeces and correctly disposing of it, dog owners can reduce the input of nitrogen to the soil by 57% and phosphorus by 97%.

The best antidote to despair about the state of the natural world is to immerse yourself in it. Give these steps a try and you should hopefully discover more ways to not only lessen your footprint, but enjoy a more vibrant local environment.


Five options for restoring global biodiversity after the UN agreement

Henrik Svedäng– Researcher, Marine Ecology, Stockholm University

To slow and reverse the fastest loss of Earth’s living things since the dinosaurs, almost 200 countries have signed an agreement in Montreal, Canada, promising to live in harmony with nature by 2050. The Kunming-Montreal agreement is not legally binding but it will require signatories to report their progress towards meeting targets such as the protection of 30% of Earth’s surface by 2030 and the restoration of degraded habitats.

Not everyone is happy with the settlement, or convinced enough has been promised to avert mass extinctions. Thankfully, research has revealed a lot about the best ways to revive and strengthen biodiversity – the variety of life forms, from microbes to whales, found on Earth.

Here are five suggestions:

1. Scrap subsidies

The first thing countries should do is stop paying for the destruction of ecosystems. The Montreal pact calls for reducing incentives for environmentally harmful practices by $US500 billion (£410 billion) each year by 2030.

Research published in 2020 showed that ending fuel and maintenance subsidies would reduce excess fishing. Less fishing means more fish at sea and higher catches for the remaining fleet with less effort. The world’s fisheries could cut emissions and become more profitable.

Scrapping policies which subsidise overexploitation in all sorts of industries – fisheries, agriculture, forestry, and of course, fossil fuels – are in many cases the lowest fruit to be picked in order to save biodiversity.

2. Protect the high seas

Almost half of the surface of the Earth is outside national jurisdiction. The high seas belong to no one.

Most of the world’s oceans are owned by no one. (light blue = exclusive economic zones; dark blue = high seas) B1mbo / wiki (data: VLIZ), CC BY-SA

In the twilight zone of the ocean, between 200 and 1,000 metres down, fish and krill migrate upwards to feed at night and downwards to digest and rest during the day. This is the ocean’s biological pump, which draws carbon from near the ocean’s surface to its depths, storing it far from the atmosphere and so reducing climate change.

The total mass of fish living in the open ocean is much greater than in overfished coastal seas. Though not exploited to any large extent yet, the high seas and the remote ocean around the Antarctic need binding international agreements to protect them and the important planetary function they serve, which ultimately benefits all life by helping maintain a stable climate.

3. Ban clear-cutting and bottom trawling

Certain methods of extracting natural resources, such as clear-cutting forests (chopping down all the trees) and bottom trawling (tugging a big fishing net close to the seafloor) devastate biodiversity and should be phased out.

Clear-cutting removes large quantities of living matter that will not be replenished before the forest has regenerated, which may take hundreds of years, particularly for forests in Earth’s higher latitudes. Many species which are adapted to live in fully grown forests are subsequently doomed by clear-cutting.

Aerial shot of rainforest and deforested land
Bad for biodiversity. Richard Whitcombe / shutterstock

Bottom trawling catches fish and shellfish indiscriminately, disturbing or even eradicating animals which live on the seafloor, such as certain types of coral and oysters. It also throws plumes of sediment into the water above, emitting greenhouse gases which had been locked away. Seafloors that have been trawled continuously for a long time may appear to be devoid of life, or trivialised with fewer species and less complex ecosystems.

4. Empower indigenous land defenders

Indigenous people are the vanguard of many of the best-preserved ecosystems in the world. Their struggle to protect their land and waters and traditional ways of using ecosystems and biodiversity for livelihoods are often the primary reason such important environments still exist.

Such examples are found around the world, for example more primates are found on indigenous land than in surrounding areas.

5. No more production targets

Many management practices will have to change, since they are based on unrealistic assumptions. Fisheries, for instance, target a maximum sustainable yield (MSY), a concept developed in the mid 20th century which means taking the largest catch from a fish stock without diminishing the stock in the future. Something similar is also used in forestry, though it involves more economic considerations.

Fishing boat with lots of seagulls
Fishing for herring near Norway. Alessandro De Maddalena / shutterstock

These models were heavily criticised in the subsequent decades for oversimplifying how nature works. For instance species often contain several local populations which live separately and reproduce only with each other, yet some of these “substocks” could still become overfished if just one production target was applied for all of them. However, the idea of a maximum sustainable yield has come back into fashion this century as a means to curtail overfishing.

Herring is a good example here. The species forms many different substocks across the North Atlantic, yet one maximum yield was adopted over vast areas. In the Baltic Sea for instance, Swedish fishing rights were given to the largest shipowners as a part of a neoliberal economic policy to achieve a more effective fishing fleet. Local stocks of herring are now declining, and with them local adaptations (genetic diversity) could eventually disappear.

Heading for more robust strategies than elusive optimal targets for extracting the most fish or trees while maintaining the stock or the forest may lead to a more resilient pathway regarding biodiversity and climate mitigation. It could involve lower fishing quotas, but also change from industrial fishing to more local fishing with smaller fishing vessels.


UN biodiversity conference: what does living in harmony with nature look like?

Alexandra Zimmermann– Senior Research Fellow, University of Oxford

The 196 countries meeting for the UN Convention on Biological Diversity conference (COP15) in Montreal, Canada, are negotiating a new set of targets for reversing the loss of Earth’s biodiversity. They have set themselves a formidable challenge: ensuring humanity is “living in harmony with nature” by 2050.

As part of this aim, and for the first time in an international agreement, nations are also being asked to work towards resolving human-wildlife conflict. When Swiss farmers fear losing livestock to rebounding wolf populations or the return of tigers threatens communities in Nepal, conservation can reach an impasse. These conflicts magnify the costs of biodiversity to local people – and, when left unresolved or handled badly, fuel tensions that erode support for protecting nature more broadly.

Standing by to help is the International Union for the Conservation of Nature (IUCN)‘s Human-Wildlife Conflict and Coexistence Specialist Group – a global expert body which I chair. We convene the best knowledge available and are producing global guidelines and hosting a three-day international conference on managing these kinds of conflict in Oxford from March 30 next year.

Resolving conflict and achieving coexistence is far from easy. While all human-wildlife conflicts revolve around the risks that animals can pose to human interests – and the persecution of those animals in retaliation – these situations also provoke disagreements among groups of people. For example, although wolves can and do occasionally kill sheep in Europe and North America, conflict primarily arises between those who want to cull wolves and those who want to protect them. Tensions escalate, mistrust and divisions ensue and each group becomes increasingly entrenched in its view of the situation, blocking progress.

Cows peer over a wire fence.
Fences are easy to install. Resolving disagreements in the local community is more difficult. Groomee/Shutterstock

Because of this, resolving conflicts about wildlife is not a simple matter of installing fences, lights or noisemakers to keep animals away from crops, property or livestock. Resolving human-wildlife conflicts means resolving divisions and disharmony between people. This, more than any fence, is ultimately what makes coexistence possible. This means identifying any underlying grievances and addressing these through dialogue, engaging everyone involved in a joint agreement.

Without this groundwork, any practical measures outsiders suggest to communities for keeping wildlife at bay are likely to be poorly implemented or rejected altogether.

Measuring what matters

Following COP15, each country dealing with human-wildlife conflict at home will need technical and financial support to manage it. They will also, once the new agreement comes into effect, be required to track and monitor their progress towards all of the newly agreed targets, including that of “…minimis[ing] human-wildlife conflict for coexistence”. For this, a standard set of measurements called indicators are needed – which are also still under negotiation.

Yet here lies another challenge: countries deal with unique situations, ranging from maintaining coexistence with crocodiles in India to managing disputes over bats in Mauritius. Countries need to apply locally appropriate and culturally sensitive approaches to resolve these conflicts, while at the same time monitoring their performance in a globally standardised and comparable way.

Exactly how this should be done remains a sticking point in these negotiations. Just as resolving conflicts is not as simple as putting up barriers between wild animals and people, merely counting how often a crop is trampled by elephants or how many lions are shot in retaliation for preying on cows is insufficient. If the aim was only to reduce those numbers, then the simplest solution would be to remove all the animals or all the people – but that wouldn’t be coexistence. Rather, the aim must be for communities to balance the costs and benefits of living with wildlife, and for divisions between groups to be reconciled.

Lions prowl a water-filled track.
Living alongside large predators can be fraught with challenges. Nick Blamire-Brown/Shutterstock

Although countries will need to track incidences of damage or loss, compensation claims, and the number of people and animals killed or injured, we recommend also monitoring levels of conflict between people and relative progress in each setting in ways which are appropriate to local contexts and cultures. Such an approach could include assessing the willingness of communities to live alongside wildlife, which can be measured with social survey methods of attitudes, values and tolerance. This combination allows countries room to decide their own adaptations and encourages more holistic thinking about what makes coexistence work.

Human-wildlife conflict is both a great challenge and a great opportunity. As UN secretary general Antonio Guterres stated in his opening address to the conference:

…humanity needs to make peace with nature, because we are out of harmony with nature.


COP15: three visions for protecting nature on the table at the UN biodiversity conference

Harriet Bulkeley– Professor of Geography, Durham University

Kurit Afshen/Shutterstock

With the dust still settling on the UN climate change summit in Egypt, another round of international talks is beginning in Montreal, Canada. The UN biodiversity conference, otherwise known as COP15, will assemble world leaders to agree on new targets for protecting nature.

The loss of biodiversity – the dizzying variety of life forms from microscopic viruses, bacteria and fungi to towering trees and enormous whales – is accelerating. The last agreement in 2010 yielded the 20 Aichi targets which included halving the rate at which species were being lost and expanding protected habitats on land and in the sea by 2020. Governments failed to meet a single one.

global assessment in 2019 showed that nature was declining globally at rates unprecedented in human history. The forces driving more and more species towards extinction – climate change, habitat destruction and pollution – are all trending in the wrong direction. Nothing less than a transformation of how societies work and the relationship between people and the rest of nature will get us on track.

Read more: ‘Revolutionary change’ needed to stop unprecedented global extinction crisis

After two years of delay due to the pandemic and difficulties negotiating a new venue with the country that holds the conference presidency, China, many are relieved that COP15 is happening at all. That relief may prove short-lived as there is much to be done in these two short weeks. The grand objective is the approval of a new global biodiversity framework, essentially a plan for how the world’s nations expect to halt the loss of biodiversity and ensure that, by 2050, society is living in harmony with nature.

Bare ground strewn with branches and tree stumps with tropical forest in the distance.
Deforestation in the Brazilian Amazon broke records in the first half of 2022. Paralaxis/Shutterstock

30% by 2030

One debate which has dominated discussions so far is how much land and sea should be set aside for conservation. The current text aims for 30% by 2030. Some scientists believe this is insufficient, and that preserving half the Earth for nature is necessary. Others are wary of reviving failed ideas which have tried to boost wildlife by expelling people and erecting walls to keep them out.

Negotiators will debate whether a 30×30 target should be met at the national level or globally. The former would mean each country meeting this standard within its own borders. The latter would prioritise Earth’s most important areas of biodiversity (such as tropical rainforests) but oblige countries with large remaining wildernesses (overwhelmingly in developing countries) to shoulder the lion’s share of conservation work. Many poorer countries foresee this stopping their economic development.

There is also disagreement over what level of protection should be given to these areas and how the rights of people living within them should be recognised. These plans would require a doubling of protected areas on land and perhaps as much as a tenfold increase in the oceans. But they could exclude indigenous people and those who make their living from cultivation, forestry and fishing.

Two rangers look out over a lake in a sandy plain.
Protected areas can have insidious consequences. EPA-EFE/Paolo Pena/Peru Mineria

Less emissions, less meat, less waste

Instead of concentrating on the total area reserved for nature, recent research highlights the importance of addressing the underlying causes of extinctions and habitat loss, such as greenhouse gas emissions, meat consumption and plastic pollution.

Targeting the processes driving biodiversity loss would shift attention away from where nature is being destroyed to the places where these processes are guided and sustained: boardrooms, trading floors, local planning offices and supermarkets.

The framework under negotiation includes several targets that would restrain the destruction, from eliminating policies subsidising the conversion of forest to cow pasture to halving food waste. These have failed to attract the momentum behind flashier goals like the 30×30 target. Changing how economies and societies function is more contentious and asks more from rich countries with more influence over the drivers of biodiversity loss.

Safeguard nature’s services

Yet another approach would safeguard the services nature generates, including flood protection, wood fuel, climate regulation and food provision. And it would identify the natural assets (wetlands, forests, coral reefs and mangroves to name a few) that must endure for these services to continue. This would mean protecting nature close to where it is most needed. A staggering 6.1 billion people live within one hour of such assets.

Good COP or bad COP?

While everyone gathering in Montreal agrees that a breakthrough is needed, there are different ideas about what that should look like. For many seasoned conservationists, a good outcome will mean more stringent targets for protecting and restoring nature and more expansive protected areas, plus the money and other resources necessary to enforce them.

Businesses, investors, cities, regional governments and the communities they represent want an agreement that mobilises the whole of society. Some companies have asked that all businesses be forced to report the impacts their activities have on nature. Cities and regions have their own pledges and have asked COP15 to formally recognise their role in delivering national plans.

A coral reef with an island visible above the ocean surface.
Coral reefs offer food and protection from storms in the tropics. Ethan Daniels/Alamy Stock Photo

This could bring the protection and restoration of nature into mainstream thinking around how economies develop and societies are organised, and make the case that much of what is important about nature is not to be found on the other side of a fence. This trend is evident in growing enthusiasm around nature-based solutions to climate change.

The recent UN climate summit in Egypt heralded the potential of such solutions, which include restoring peatlands and seagrass beds. These actions tackle the climate and biodiversity crisis together by expanding refuge for wildlife and drawing carbon from the air. Cities, businesses and investors smell an opportunity to meet multiple measures of sustainable development at once.

Some conservationists worry these supposed solutions are greenwashing and allow companies to exploit indigenous people and communities. Other experts argue that, with the right safeguards in place, these fears can be put to rest.

With much at stake, in seeking to straddle different agendas, COP15 risks achieving none.


We found Britain’s greenest city centre – and its least green

Jake M Robinson– Ecologist and Researcher, Flinders University

Paul Brindley– Senior Lecturer, Department of Landscape Architecture, University of Sheffield

Meet the winner: Exeter. Panoptic Motion / shutterstock

Some of Britain’s city centres are filled with trees and parks, while others have little vegetation to break up the bricks, tarmac and concrete. Such differences aren’t just aesthetic: they affect whether animals can move around, and they have implications for human health and social equity.

That’s why we wanted to properly assess how green these cities are. In our latest research, now published in the open-access journal PLOS ONE, we looked at all 68 municipalities in Great Britain with populations of at least 100,000. City centres were defined using Consumer Data Research Centre spatial datasets, which use complex statistics to demarcate retail boundaries. You can think of the boundaries as similar to “central business districts”. In Sheffield, for instance, the city centre is the entire area within the central ring road. London is a special case; because it is so large, it has several of these areas.

satellite map of a city
Sheffield has plenty of green space – but not within the city centre ring road. Google EarthCC BY-SA

For each of these cities, we assessed three metrics of “greenness”: 1) tree cover using an algorithm to randomly sample recent aerial imagery, 2) the presence of green spaces using open-source data from Ordnance Survey (Great Britain’s national mapping agency), and 3) the normalised difference vegetation index (NDVI), which uses satellite observations of light absorption and reflection to measure vegetation cover in a given area.

Exeter greenest, Glasgow least green

Combining all three metrics into a single greenness score, we found that Exeter’s urban centre ranks highest, followed by Islington in London, Bristol, Bournemouth and Cambridge.

Glasgow’s urban centre is the least green, with Middlesbrough, Sheffield, Liverpool and Leeds also in the lowest five. Tree coverage is probably the most relatable way to describe the differences: trees cover 12% of the total land area of Exeter city centre, but just 2% of Glasgow’s.

City centre buildings, grey sky
Greenless Glasgow. leppäkerttu/pixabayCC BY-SA

Exeter, a small city in England’s remote south-west, largely avoided the rapid industrial growth of better-connected cities. This is apparent today in its leafy streets and the meadows along the River Exe. In contrast, places like Glasgow and Sheffield were massive industrial powerhouses with considerable urban sprawl, though they do still have luscious parks outside of their city centres.

North-south green divide

It is worth noting that the top five urban centres are all in the south of England, while the bottom five are ex-industrial areas in the north or Scotland. In fact, only 25% of all northern cities are in the top half of the greenness table. Further analysis uncovered a statistical link between a lower greenness score and higher levels of deprivation, as measured according to crime risk, health, economics, education, and other related metrics. In addition, areas with larger populations had lower tree coverage and vegetation index scores.

City greenness infographic
The top and bottom five. Anne-Lise Paris / PLOS, Author provided

Sheffield – where the study was conducted – is often billed as having one of the highest densities of trees out of all European cities. But this is due to the vast swathes of trees in the suburban areas and surrounding fringe of the Peak District national park. Our work shows that Sheffield actually has the lowest city centre tree cover out of all the cities included in the study.

The reasons for the north-side divide are complex and can depend on decisions made centuries ago and development since. Clearly, some urban centres invested in parks and tree-lined avenues more than others in the past. Industry and war efforts then contributed to urban sprawl and reduced natural features in certain urban centres, particularly in northern England and Scotland.

In the 19th century, city planners often incorporated street trees, particularly in affluent areas. These decisions were influenced by an admiration of continental European boulevards and the wellbeing benefits of “garden cities” and “spa towns”. This is exemplified by the “luxury effect” whereby affluent neighbourhoods record higher biodiversity in cities around the world, often dictated by structural classism and racism.

Differences in historical development have therefore left us with leafy urban centres like Exeter’s, and others with far less greenness. The question remains why over time such imbalances have not been addressed.

It’s an important question as around 70% of the world’s population will soon live in urban environments. In the UK, 84% of people already do. This rapid rise in urbanisation has led to a disconnect between humans and nature as we often fail to create healthy and biodiverse spaces, especially in city centres.

But there is at least one reason to be hopeful. Urban centres in Great Britain and other areas of the world are changing, especially as digital shopping means many retail outlets are closing. This is a problem in many ways, but it’s also an opportunity. The decline of in-person shopping gives us a chance to re-envision and redevelop urban centres to enhance their green spaces.


Cohousing is empowering people to fight back against a global housing crisis

Johannes Novy– Senior Lecturer in Urban Planning, School of Architecture and Cities, University of Westminster

Cohousing developments provide ample outdoor space for children to play in. Gary Calton | Alamy

The debate around how to fix the global housing crisis usually hinges on whether more market or more state is required. Some people stress the need for additional housing stock and less regulatory red tape, so that the market can create it. Others claim that stricter government measures – against ruthless developers and landlords, more rent control, and more public housing – are crucial.

Increasingly, policymakers are paying attention to what lies between the public and private sectors. The United Nations’ New Urban Agenda – a key international policy framework to promote sustainable urban development – highlights the benefits of “cooperative solutions, such as cohousing, community land trusts and other forms of collective tenure”. A slew of recent community-led housing projects across Europe and beyond show how this can work.

Cohousing includes all kings of edifices, new and existing. It is not tied to a particular type of tenure. And the groups of people it involves can vary considerably in size. At its heart are two key principles. Residents do not only live next to each other, but with each other, in buildings that comprise communal spaces and facilities. And they take the lead, or at least are involved in, the design and management of their communities.

Communal life

German sociologist Anja Szypulski has lauded the “abundant potential” cohousing proffers for sustainable housing and neighbourhood development. The first way it does this is by promoting an ethos of participation and sharing.

Residents are involved throughout the building process. When, in the wake of the 2008 financial crash, a developer pulled out of a state-owned site in Cambridge, the city council opted for a cohousing initiative to build on the land instead, precisely because of the social and community benefits that would bring.

The resulting Marmalade Lane project opened in 2018 after four years, during which the cohousing members developed the architectural brief, sought planning permission and contracted builders.

Residents also often take part in actually building their homes too. The Church Grove project in Lewisham, south London, is a community-led housing development on a old derelict school and industrial site. When completed it will count 36 homes designed to be permanently affordable. To keep the costs low, future residents are involved in this construction process. They have already built a communal hall on the site.

Communality also shapes daily life in a cohousing project. Marmalade Lane residents share 42 homes – houses and flats, both – organised around a common house with a shared kitchen, refectory and fireplace, a pedestrianised lane, outdoor play area and garden, a laundry, a gym and a workshop.

Similarly, La Borda, in Barcelona, is a cooperative housing block comprising 28 apartments, organised around a communal, open-plan atrium. Residents share a kitchen-dining area, a laundry room, guest rooms and generous outdoor spaces. Their flats were deliberately designed small, with movable walls, so that a room belonging to one flat could become part of another, as the need arose.

A building facade with columns, large windows and bikes out front.
The facade of the La Borda cohousing development in Barcelona. VELKEJ LED | WikimediaCC BY-SA

Socially and architecturally sustainable

The La Borda project contributes to the wider community, too, by organising events and sourcing goods from local cooperatives. It is based on a participatory planning process and costs have been kept low through the use of smart low-tech solutions and a lot of self-help during construction by its future users, who are also responsible for the maintenance and management of the project. Decisions are made collectively in a general assembly and all adults participate in various committees that deal with different issues, from financial matters to communal dinners

While the idea of committee meetings and doors facing each other won’t appeal to everyone, the benefits of knowing you’re not alone are clear. Residents at Marmalade Lane have spoken about children playing together, stay-at-home mothers not feeling isolated and retirees being engaged and occupied.

The UK Cohousing network describes cohousing as a “way of resolving the isolation many people experience today, recreating the neighbourly support of the past”. And research bears this out. A recent study on the way cohousing dwellers in the UK coped with lockdown found that many residents experienced a level of mutual support and care that went well beyond the general good neighbourliness of the early days of the pandemic.

Cohousing projects also encourage sustainability by typically being built for the long term. The Marmalade Lane buildings used environmentally-friendly materials and designs that promote low-energy use for a small carbon footprint.


Seasonal depression: small things you can do every day to cope

Jolanta Burke– Senior Lecturer, Centre for Positive Psychology and Health, RCSI University of Medicine and Health Sciences Annie Curtis– Senior Lecturer, School of Pharmacy and Biomolecular Sciences (PBS), RCSI University of Medicine and Health Sciences

Daylight is important, so try to get outside for a walk in the morning and afternoon. Dasha Petrenko/ Shutterstock

Many of us tend to feel sad or not like our usual self as autumn and winter approach. But for some, these feelings persist until spring arrives.

Known as seasonal affective disorder (or Sad), it’s a type of depression that occurs only during specific seasons. Alongside persistent low mood, some people may find they feel more lethargic than usual, have difficulty getting up in the morning and crave more carbs than normal.

If you’re someone who has Sad (or think you might), here are a few things you can do to improve your mood during the colder months.

What to do every day

Since Sad happens during seasons when the days are shorter and we get less sunlight, it’s thought to be caused by a disruption of our body clocks (also known as circadian-rhythm disturbance). We all have a “master clock” in the brain that uses daylight to control all of our body’s processes – from hunger to when we feel ready for bed.

Circadian rhythm disturbance has been linked to sleep disturbances, changes in mood and our eating patterns and metabolism, all of which are affected by Sad.

This is why getting outside and into natural daylight can be so important for people who have Sad.

In the morning, aim to get outside for at least a few minutes. Since light sends direct signals to your master body clock to tell it it’s time to wake up, morning light will help you feel more alert throughout the day. It may also help you fall asleep earlier in the evening.

At lunch, try again to get outside and get more natural light exposure. But if you can’t get outside or it’s overcast, you may want to try bright-light therapy. This exposes people to bright fluorescent light using a special lamp or mask. Research shows that 30 minutes of bright light therapy daily can help reduce symptoms of Sad.

A woman uses a fluorescent lightbox in her home to help treat her seasonal depression.
Light therapy may help on days that are overcast. Image Point Fr/ Shutterstock

If you find it difficult to convince yourself to get away from your desk at lunchtime, try to organise some activities to do that may help you get outside. For example, try to organise a daily lunchtime group walk with your colleagues or neighbours. Alongside getting you out into the daylight, exercising in a group can also boost positive emotions and connectedness, which is good for wellbeing and mental health.

Another activity you could try during your lunchtime walk is the “three good things in nature” task. The aim of this activity is to boost mindfulness and appreciation of nature by taking note of at least three things from the natural environment while you’re on your daily walk. Not only will this get you outside, it may also help improve your mood and wellbeing.

In the evenings, aim to set aside time to do things you enjoy. This may help to improve your mood and may ease some symptoms of Sad.

Other things you can do during winter months to improve your mood include:

Practise humour
Introducing more humour into your life may help balance out your negative emotions and could even improve sleep quality, mood and reduce symptoms of depression.

In the evening, take ten minutes to think of some funny things that happened during the day. Or think of a challenging situation you faced and instead try to think about how you’d deal with it in a funny way in the future. Making the time to watch something funny on TV three or four times a week may also help to boost your mood.

Find a hobby
Start a new hobby or pick up one you haven’t practised for a while. Engaging in a hobby will keep your mind less idle and more engaged, leaving you with less time to ruminate, if that’s something you tend to do. Perhaps try learning to knit. This is associated with increased mindfulness, calmness and a boost of positive emotions. Mastering new recipes may also be a great way of boosting wellbeing.

It doesn’t matter what hobby you choose, as long as it stretches your skills and helps you get into a state of flow. This is the feeling of “losing yourself” in what you’re doing and is a major component in experiencing subjective happiness. You might not feel better while you are doing your hobby (as it requires concentration), but as soon as you complete your task, you will experience a sense of accomplishment and a boost of positive emotions.

Keep your body clock in rhythm
Since Sad is thought to be caused by circadian-rhythm disturbance, keeping your circadian rhythm in time may help to reduce symptoms of Sad.

Sleep plays a big role in keeping your body clock in check. So in the evenings, try to avoid too much bright light as this will delay your sleep. You should also try to keep similar times for going to sleep and waking up both during the week and on weekends. Alongside proper sleep, eating your meals at regular times may also help to keep your body clock in time.

While it may be normal to feel a dip in your mood after the clocks first change, if you’re finding that symptoms are lingering for many weeks or are having a big effect on your life, you may want to speak to your doctor. In the meantime, remember that even just a few small changes every day may help keep Sad symptoms at bay.


Coastal erosion is unstoppable – so how do we live with it?

Sophie A. Day– Senior Research Associate in Environmental Sciences, University of East Anglia Robert James Nicholls– Professor of Climate Adaptation, University of East Anglia

Sophie Day, Author provided

A record storm surge in 1953 devastated much of eastern England’s coast, prompting prolific investment in concrete sea walls, wooden groynes and other engineered structures designed to protect the coastline from erosion. These measures brought a reassuring sense of permanence for people in previously risky locations. Houses atop sandy cliffs and tucked behind or among sand dunes went from being holiday homes to permanent residences, and new homes were built nearby.

But decades later, the east coast and other parts of England are still eroding – rapidly in some places – despite efforts to hold the coastline in place.

England has some of the fastest eroding coastline in Europe, particularly along the Norfolk and Yorkshire coasts. Historical records show that England’s soft and sandy east coast has always been subject to retreat. The numerous lost villages beneath the North Sea are testament to this.

A beach lined with wooden groynes and other structures.
Sea walls and other structures cannot hold the coastline together forever. Sophie Day, Author provided

Back in 2018 the Committee on Climate Change, which advises the UK government, calculated that around 9,000 properties in England are located in areas likely to be lost to coastal erosion by 2025. This number is projected to increase 15-fold by the end of the century, disrupting whole communities as more buildings, roads and farmland inevitably slip into the danger zone.

Unstoppable – and necessary?

A growing body of research warns that the speed of coastal erosion will be compounded by sea-level rise and other effects of climate change, such as more extreme storms and prolonged wet weather, as waterlogged soils increase the likelihood of sandy cliffs collapsing. Rates of erosion can be roughly but not precisely estimated, due to the complexity of coastal systems and uncertainty regarding how the effects of climate change will manifest.

A paved road ending in a sheer cliff edge.
Life in an eroding community can be unpredictable. Sophie Day, Author provided

Since the early 1990s, scientists have collected huge amounts of data in order to understand how the wind, waves, tides and storms shape coastlines. The evidence indicates that it is not possible or prudent to stop or delay coastal erosion forever and that in some places, it may even be necessary.

This is because when soft cliffs such as those along the east of England retreat, they release a lot of sand which is deposited on nearby beaches, making them higher and wider. High and wide beaches absorb the energy of waves, giving some protection to cliffs, dunes and sea walls from coastal erosion and flooding.

The chief executive of the UK Environment Agency recently said it is inevitable that at some point communities will have to move back from the coast. So what does this mean for people who live in places where coastal erosion is accelerating, or where it can no longer be stopped?

At Happisburgh in north Norfolk for example, a section of old and damaged sea defences had to be removed in the 1990s to avert dangerous collapse. Rapid erosion of the beach and cliffs since the early 2000s has meant homes in this village being steadily demolished as the coastline retreats. As yet there are no arrangements to compensate people here, or other government policies to help them adapt.

A series of collapsed houses along a sandy outcrop.
Uprooted. Sophie Day, Author provided

Living with coastal erosion

It is important to be realistic: homes, roads and other things which knit some coastal communities together will need to be relocated inland away from danger – and soon. But doing this is far from simple, and will certainly be costly.

Ideally, the kind of investment which erected coastal defences in the aftermath of the 1953 storm surge would be mobilised today to help these places move. This is a pressing issue – letting crisis and despair characterise life for coastal communities on the edge is unsustainable and unfair.

Slowly, things are changing. A network of coastal communities, local authority officers and politicians, academics and others have worked since the early 2000s to argue for what is needed to cope with and prepare for coastal erosion around England and Wales. Now, a new pulse of government funding could test these ideas so that in future, no community feels abandoned to the sea.

An abandoned building behind a metal fence.
Eroding coastal communities need reassurance and support. Sophie Day, Author provided

Part of this work will be to begin the transition in eroding towns and villages on England’s east coast from a state of crisis to one in which people can begin to live feeling safe and confident. It must be systematically worked out how communities can move away from risky areas while maintaining homes, utilities and services, as well as preserving local heritage, culture and each place’s unique character.

As academics working alongside government agencies, our next challenge will be ensuring these time-limited projects translate into robust national policy and funding. Coastal erosion cannot be stopped, so we must help everyone relearn how to live with it.


Climate tipping points could lock in unstoppable changes to the planet – how close are they?

David Armstrong McKay– Researcher in Earth System Resilience, Stockholm University

Continued greenhouse gas emissions risk triggering climate tipping points. These are self-sustaining shifts in the climate system that would lock-in devastating changes, like sea-level rise, even if all emissions ended.

The first major assessment in 2008 identified nine parts of the climate system that are sensitive to tipping, including ice sheets, ocean currents and major forests. Since then, huge advances in climate modelling and a flood of new observations and records of ancient climate change have given scientists a far better picture of these tipping elements. Extra ones have also been proposed, like permafrost around the Arctic (permanently frozen ground that could unleash more carbon if thawed).

Estimates of the warming levels at which these elements could tip have fallen since 2008. The collapse of the west Antarctic ice sheet was once thought to be a risk when warming reached 3°C-5°C above Earth’s pre-industrial average temperature. Now it’s thought to be possible at current warming levels.

In our new assessment of the past 15 years of research, myself and colleagues found that we can’t rule out five tipping points being triggered right now when global warming stands at roughly 1.2°C. Four of these five become more likely as global warming exceeds 1.5°C.

These are sobering conclusions. Not all of the news coverage captured the nuance of our study, though. So here’s what our findings actually mean.

Uncertain thresholds

We synthesised the results of more than 200 studies to estimate warming thresholds for each tipping element. The best estimate was either one that multiple studies converged on or which a study judged to be particularly reliable reported. For example, records of when ice sheets had retreated in the past and modelling studies indicate the Greenland ice sheet is likely to collapse beyond 1.5°C. We also estimated the minimum and maximum thresholds at which collapse is possible: model estimates for Greenland range between 0.8°C and 3.0°C.

A vast wall of blue and white ice with ocean in the foreground.
Greenland’s ice sheet is showing signs of destabilising at current warming levels. David Dennis/Shutterstock

Within this range, tipping becomes more likely as warming increases. We defined tipping as possible (but not yet likely) when warming is above the minimum but below the best estimate, and likely above the best estimate. We also judged how confident we are with each estimate. For example, we are more confident in our estimates for Greenland’s ice sheet collapse than those for abrupt permafrost thaw.

This uncertainty means that we do not expect four climate tipping points to be triggered the first year global temperatures reach 1.5°C (which climate scientists suggest is possible in the next five years), or even when temperatures averaged over several years reach 1.5°C sometime in the next couple of decades. Instead, every fraction of a degree makes tipping more likely, but we can’t be sure exactly when tipping becomes inevitable.

This is especially true for the Greenland and west Antarctic ice sheets. While our assessment suggests their collapse becomes likely beyond 1.5°C, ice sheets are so massive that they change very slowly. Collapse would take thousands of years, and the processes driving it require warming to remain beyond the threshold for several decades. If warming returned below the threshold before tipping kicked in, it may be possible for ice sheets to temporarily overshoot their thresholds without collapsing.

For some other tipping points, change is likely to be more dispersed. We estimate that both tropical coral reef death and abrupt permafrost thaw are possible at the current warming level. But thresholds vary between reefs and patches of permafrost. Both are already happening in some places, but in our assessment, these changes become much more widespread at a similar time beyond 1.5°C.

Elsewhere, small patches of the Amazon and northern forests might tip and transition to a savannah-like state first, bypassing a more catastrophic dieback across the whole forest. Model results that are yet to be published suggest that Amazon tipping might occur in several regions at varying warming levels rather than as one big event.

An aerial view of burning Amazon rainforest surrounded by bare fields.
The Amazon may not collapse from forest to grassland all at once. Paralaxis/Shutterstock

There may also be no well-defined threshold for some tipping elements. Ancient climate records suggest ocean currents in the North Atlantic can dramatically flip from being strong, as they are now, to weak as a result of both warming and melting freshwater from Greenland disrupting circulation. Recent modelling suggests that the threshold for the collapse of Atlantic circulation depends on how fast warming increases alongside other hard-to-measure factors, making it highly uncertain.

Into the danger zone

There are signs that some tipping points are already approaching. Degradation and drought have caused parts of the Amazon to become less resilient to disturbances like fire and emit more carbon than they absorb.

The front edge of some retreating west Antarctic glaciers are only kilometres away from the unstoppable retreat. Early warning signals in climate monitoring data (such as bigger and longer swings in how much glaciers melt each year) suggest that parts of the Greenland ice sheet and Atlantic circulation are also destabilising.

These signals can’t tell us exactly how close we are to tipping points, only that destabilisation is underway and a tipping point may be approaching. The most we can be sure of is that every fraction of further warming will destabilise these tipping elements more and make the initiation of self-sustaining changes more likely.

This strengthens the case for ambitious emissions cuts in line with the Paris agreement’s aim of halting warming at 1.5°C. This would reduce the chances of triggering multiple climate tipping points – even if we can’t rule out some being reached soon.