Can London's farmers survive the housing crisis?

The farm horse competition at the 95th annual Middlesex Agricultural Meeting at Harmondsworth, 1933. The village is now conveniently situated for Heathrow Airport. Image: Getty.

A tenth of London’s land is still free of housing, shops or concrete sprawl. Instead, it is used for growing food.

There are more than 450 farms growing crops or rearing livestock in the bounds of Greater London. More than half of the 12,000 hectares are in the city’s east and southeast. The rest is mostly in the northwest.

That’s not just a curiosity in a capital of 8.6m people. Those people need homes, and there’s already a lack of housing.

We’ve heard this week that building on the green belt might help. It covers 22 per cent of London’s land, and up to two-thirds of that is farmed. A report by charity Shelter and consultancy Quod argued that, if we are to build 50,000 homes a year, building on green belt has to be an option.

So far both mayoral frontrunners, Zac Goldsmith and Sadiq Kahn, have ruled it out. But is farmland a good use of space?

A 2015 report, from the free market Adam Smith Institute, claimed intensive agriculture in London was wasteful. But in 2010, the London Assembly’s Planning and Housing Committee concluded the opposite in 2010:

There is a good case to be made that commercial agriculture is one of the best and most productive land uses in the Green Belt. The benefits include: opportunities for local job creation, skills development, regeneration, preservation and management of green space, potential for waste management, providing healthy locally produced food and so reducing food packaging and food miles, and the potential for improving food security.

London makes a show of feeding itself. There has been an urban farming boom. Start-ups are growing salad in rooftop containers, or underground in old air raid shelters. Food network Capital Growth has counted more than 2,500 “growing spaces”, in gardens, schools or small patches of green.

But self-sufficiency is a dream. Those innovative schemes are often expensive and will barely dent the city’s food demand. The green belt commercial farms are about half the size of the national average. And most of their milk, meat and grain will head outwards to be processed in factories, anyway. So why protect the land?

London farmer John Hunter already feels the urban encroachment. He grows crops on land rented from different landlords, including the borough of Enfield. Some of his neighbours within 10 miles have had whole farms earmarked for development. “I don’t feel secure about the long-term future of being here,” Hunter says.

He is realistic about the weak business case for growing food in London. It only happens for moral or historic reasons, he says. But farmers also make the green belt tidy and worth-protecting.

“I know when we have walked away from corners of fields it doesn’t take long for the brambles and the self-seeding saplings to start growing — then you have got a little scrubland,” he says. “I am sure people like to see the seasons in their countryside. There must be a feel-good factor for those living here or driving through.”


Philip Skinner, a dairy farmer on London’s southern fringe, says it would be sad for the green belt farms to disappear. There are advantages to farming near lots of people, especially if they’ve got money, he says. There are ways to make extra cash, like running a shop or market, letting fields to horse-owners, or using barns for car and coach storage.

Skinner expects all the smaller pockets of land to be filled in over the coming decades, as the fast growth continues in southern suburbs like Croydon. But he says the experience of California’s fertile Santa Clara Valley is still a long time off.

“What is now Silicon Valley was one of the most productive growing areas in America. But, as Silicon Valley industries grew, they stopped growing prunes. We are not quite like that yet.”

There’s a risk of being city-centric, here. Londoners are not the only people who could lose their countryside.

William Westacott, who milks 190 cows in the first green valley to the south east of the city in Kent, admits he lives in a bubble. His landlord is the Chevening Estate, whose grand house is an official residence of the British Foreign Secretary. The trustees won’t allow major residential building on their land.

He says pressure to keep green spaces comes from the commuter belt, not just the metropolis. Sevenoaks, a wealthy town, is 15 minutes drive away, just beyond the M25. Its residents enjoy walking and cycling in the hills around Westacott’s farm.

“Most of the development I am hearing about tends to be the other side of the motorway, in other towns,” he says. “The infilling that people have predicted may not even happen.”

There are important decisions to be taken about London’s green space. But they are not London’s choices alone.

Charlie Taverner tweets as @charlietaverner.

 
 
 
 

How bad is the air pollution on the average subway network?

The New York Subway. Image: Getty.

Four more major Indian cities will soon have their own metro lines, the country’s government has announced. On the other side of the Himalayas, Shanghai is building its 14th subway line, set to open in 2020, adding 38.5 km and 32 stations to the world’s largest subway network. And New Yorkers can finally enjoy their Second Avenue Subway line after waiting for almost 100 years for it to arrive.

In Europe alone, commuters in more than 60 cities use rail subways. Internationally, more than 120m people commute by them every day. We count around 4.8m riders per day in London, 5.3m in Paris, 6.8m in Tokyo, 9.7m in Moscow and 10m in Beijing.

Subways are vital for commuting in crowded cities, something that will become more and more important over time – according to a United Nations 2014 report, half of the world’s population is now urban. They can also play a part in reducing outdoor air pollution in large metropolises by helping to reduce motor-vehicle use.

Large amounts of breathable particles (particulate matter, or PM) and nitrogen dioxide (NO2), produced in part by industrial emissions and road traffic, are responsible for shortening the lifespans of city dwellers. Public transportation systems such as subways have thus seemed like a solution to reduce air pollution in the urban environment.

But what is the air like that we breathe underground, on the rail platforms and inside trains?

Mixed air quality

Over the last decade, several pioneering studies have monitored subway air quality across a range of cities in Europe, Asia and the Americas. The database is incomplete, but is growing and is already valuable.

Subway, Tokyo, 2016. Image: Mildiou/Flickr/creative commons.

For example, comparing air quality on subway, bus, tram and walking journeys from the same origin to the same destination in Barcelona, revealed that subway air had higher levels of air pollution than in trams or walking in the street, but slightly lower than those in buses. Similar lower values for subway environments compared to other public transport modes have been demonstrated by studies in Hong Kong, Mexico City, Istanbul and Santiago de Chile.

Of wheels and brakes

Such differences have been attributed to different wheel materials and braking mechanisms, as well as to variations in ventilation and air conditioning systems, but may also relate to differences in measurement campaign protocols and choice of sampling sites.

Second Avenue Subway in the making, New York, 2013. Image: MTA Capital Construction/Rehema Trimiew/Wikimedia Commons.

Key factors influencing subway air pollution will include station depth, date of construction, type of ventilation (natural/air conditioning), types of brakes (electromagnetic or conventional brake pads) and wheels (rubber or steel) used on the trains, train frequency and more recently the presence or absence of platform screen-door systems.

In particular, much subway particulate matter is sourced from moving train parts such as wheels and brake pads, as well as from the steel rails and power-supply materials, making the particles dominantly iron-containing.


To date, there is no clear epidemiological indication of abnormal health effects on underground workers and commuters. New York subway workers have been exposed to such air without significant observed impacts on their health, and no increased risk of lung cancer was found among subway train drivers in the Stockholm subway system.

But a note of caution is struck by the observations of scholars who found that employees working on the platforms of Stockholm underground, where PM concentrations were greatest, tended to have higher levels of risk markers for cardiovascular disease than ticket sellers and train drivers.

The dominantly ferrous particles are mixed with particles from a range of other sources, including rock ballast from the track, biological aerosols (such as bacteria and viruses), and air from the outdoors, and driven through the tunnel system on turbulent air currents generated by the trains themselves and ventilation systems.

Comparing platforms

The most extensive measurement programme on subway platforms to date has been carried out in the Barcelona subway system, where 30 stations with differing designs were studied under the frame of IMPROVE LIFE project with additional support from the AXA Research Fund.

It reveals substantial variations in particle-matter concentrations. The stations with just a single tunnel with one rail track separated from the platform by glass barrier systems showed on average half the concentration of such particles in comparison with conventional stations, which have no barrier between the platform and tracks. The use of air-conditioning has been shown to produce lower particle-matter concentrations inside carriages.

In trains where it is possible to open the windows, such as in Athens, concentrations can be shown generally to increase inside the train when passing through tunnels and more specifically when the train enters the tunnel at high speed.

According to their construction material, you may breath different kind of particles on various platforms worldwide. Image: London Tube/Wikimedia Commons.

Monitoring stations

Although there are no existing legal controls on air quality in the subway environment, research should be moving towards realistic methods of mitigating particle pollution. Our experience in the Barcelona subway system, with its considerable range of different station designs and operating ventilation systems, is that each platform has its own specific atmospheric micro environment.

To design solutions, one will need to take into account local conditions of each station. Only then can researchers assess the influences of pollution generated from moving train parts.

The ConversationSuch research is still growing and will increase as subway operating companies are now more aware about how cleaner air leads directly to better health for city commuters.

Fulvio Amato is a tenured scientist at the Spanish National Research CouncilTeresa Moreno is a tenured scientist at the Institute of Environmental Assessment and Water Research (IDAEA), Spanish Scientific Research Council CSIC.

This article was originally published on The Conversation. Read the original article.