Urban greenery can cool warming cities, and make us happy, too

The Bosco Verticale (Vertical Forest), Milan. Image: Getty.

The current climate and ecological crisis demands a radical redesign of how we live and organise our societies. Yet these urgent changes, though complex, are far from impossible.

Some of them are simple, beautiful, and beneficial to all. By greening our cities with street trees, urban parks, and community and rooftop gardens, we can keep ourselves cool amid rising temperatures, reverse the steady erosion of the rich tapestry of life on Earth, and foster happiness and social connection in the process.

It is widely known that greenery in urban spaces helps improve city microclimates. Thanks to heat generated by traffic and industrial activity, as well as the spread of heat-trapping concrete buildings that have steadily replaced plant life, urban air temperature is often higher than in rural environments. Hotter cities compel urban denizens to opt for air conditioners in order to stay cool, which further strains energy demands and worsens the urban heat island effect.

Plants can help cool cities through the water that evaporates from their leaves when exposed to the sun’s rays, and by shading surfaces that otherwise might have absorbed heat. Research has found that on a sunny day, a single healthy tree can have the cooling power of more than ten air-conditioning units.

Plants also help keep harmful pollutants such as microscopic particulate matter at bay through a complex process known as dry deposition, whereby particles penetrate and become trapped in the wax or cuticles of leaves. Although banning or at least restricting vehicle use in city centres is crucial, mass greening can further reduce pollution and keep cities cool in the increasingly scorching summers that lie ahead.

Urban greenery wouldn’t just help lessen the impacts of climate change and improve air quality. Evidence from a range of disciplines has uncovered numerous social, psychological, and health benefits of human exposure to green spaces. These include stress and anxiety reduction, improved cognitive functioning, lowered risks of depression, and overall greater mental and physical wellbeing.

Others have shown how involvement in community gardening can increase social cohesion and social bonds among participants and the wider community, in addition to providing local and affordable food sources.


The Japanese preventative healthcare practice of Shinrin-yoku, or “forest bathing”, is modelled on a recognition of the many benefits of immersion in natural spaces. We’re not yet sure why we seem happiest and healthiest when we’re surrounded by our fellow lifeforms. But the universality and antiquity of our appreciation for nature suggests that our biophilia may originate from the millions of years humans and plants spent co-evolving in close contact with each other.

Perhaps most importantly, greening and rewilding our cities can offer vital refuges for rapidly vanishing biodiversity. Human socioeconomic activities, especially those of the world’s rich, have destroyed natural habitats, consumed vast tracts of forest, polluted waterways, and disrupted the seasonal rhythms on which life depends. In the midst of the sixth mass extinction, many species are increasingly finding themselves with nowhere to go.

Urban rewilding can help the complex natural communities and processes that are essential for all life to flourish once again. For example, establishing wild meadows and native plant and tree communities provides pollinators and other threatened animals with new spaces to thrive, while creating spaces to reintroduce keystone species, whose presence is crucial for maintaining ecosystem diversity.

Towards a thriving future

The mass greening and rewilding of our cities is no novel or abstract ideal. It is already happening in many urban spaces around the world. The mayor of Paris has ambitious plans to “green” 100 hectares of the city by 2020. London mayor Sadiq Khan hopes to make London the world’s first “National Park City” through mass tree planting and park restoration, greening more than half of the capital by 2050.

Singapore, a partner city in the Biophilic Cities Network, is a shining example of how to incorporate “nature” into building and city designs. The Parkroyal on Pickering Hotel, for instance, is shrouded in thickly forested terraces and sky gardens that are inhabited by local insects and birds.

More cities need to follow the lead of these forward-thinking designs and initiatives. Alongside these efforts, educational programmes, such as Singapore’s Community in Nature initiative, could also be put in place to help the public learn about, respect, and appreciate wild spaces.

Of course, urban greening alone will not be enough to meet the daunting challenges ahead. We also need to fundamentally transform our growth-oriented economies and massively reduce global inequality. But giving some new life to our cities would be a great start. And it wouldn’t just benefit people but, crucially, other species as well. This is their home, too, and they deserve a more viable future.

The Conversation

Heather Alberro, Associate Lecturer/PhD Candidate in Political Ecology, Nottingham Trent University.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

 
 
 
 

“Without rent control we can’t hope to solve London’s housing crisis”

You BET! Oh GOD. Image: Getty.

Today, the mayor of London called for new powers to introduce rent controls in London. With ever increasing rents swallowing more of people’s income and driving poverty, the free market has clearly failed to provide affordable homes for Londoners. 

Created in 1988, the modern private rented sector was designed primarily to attract investment, with the balance of power weighted almost entirely in landlords’ favour. As social housing stock has been eroded, with more than 1 million fewer social rented homes today compared to 1980, and as the financialisation of homes has driven up house prices, more and more people are getting trapped private renting. In 1990 just 11 per cent of households in London rented privately, but by 2017 this figure had grown to 27 per cent; it is also home to an increasing number of families and older people. 

When I first moved to London, I spent years spending well over 50 per cent of my income on rent. Even without any dependent to support, after essentials my disposable income was vanishingly small. London has the highest rent to income ratio of any region, and the highest proportion of households spending over a third of their income on rent. High rents limit people’s lives, and in London this has become a major driver of poverty and inequality. In the three years leading up to 2015-16, 960,000 private renters were living in poverty, and over half of children growing up in private rented housing are living in poverty.

So carefully designed rent controls therefore have the potential to reduce poverty and may also contribute over time to the reduction of the housing benefit bill (although any housing bill reductions have to come after an expansion of the system, which has been subject to brutal cuts over the last decade). Rent controls may also support London’s employers, two-thirds of whom are struggling to recruit entry-level staff because of the shortage of affordable homes. 

It’s obvious that London rents are far too high, and now an increasing number of voices are calling for rent controls as part of the solution: 68 per cent of Londoners are in favour, and a growing renters’ movement has emerged. Groups like the London Renters Union have already secured a massive victory in the outlawing of section 21 ‘no fault’ evictions. But without rent control, landlords can still unfairly get rid of tenants by jacking up rents.


At the New Economics Foundation we’ve been working with the Mayor of London and the Greater London Authority to research what kind of rent control would work in London. Rent controls are often polarising in the UK but are commonplace elsewhere. New York controls rents on many properties, and Berlin has just introduced a five year “rental lid”, with the mayor citing a desire to not become “like London” as a motivation for the policy. 

A rent control that helps to solve London’s housing crisis would need to meet several criteria. Since rents have risen three times faster than average wages since 2010, rent control should initially brings rents down. Our research found that a 1 per cent reduction in rents for four years could lead to 20 per cent cheaper rents compared to where they would be otherwise. London also needs a rent control both within and between tenancies because otherwise landlords can just reset rents when tenancies end.

Without rent control we can’t hope to solve London’s housing crisis – but it’s not without risk. Decreases in landlord profits could encourage current landlords to exit the sector and discourage new ones from entering it. And a sharp reduction in the supply of privately rented homes would severely reduce housing options for Londoners, whilst reducing incentives for landlords to maintain and improve their properties.

Rent controls should be introduced in a stepped way to minimise risks for tenants. And we need more information on landlords, rents, and their business models in order to design a rent control which avoids unintended consequences.

Rent controls are also not a silver bullet. They need to be part of a package of solutions to London’s housing affordability crisis, including a large scale increase in social housebuilding and an improvement in housing benefit. However, private renting will be part of London’s housing system for some time to come, and the scale of the affordability crisis in London means that the question of rent controls is no longer “if”, but increasingly “how”. 

Joe Beswick is head of housing & land at the New Economics Foundation.