The T-Charge is a start – but to clean its air, London needs to go much further

Look at this lovely London air pollution. Image: Getty.

London's air is choking the city. Pollution from vehicles is damaging the economy, a threat to public health and the environment. 

Cleaning up London's air will not happen overnight, but this week the city has taken a step in the right direction with the introduction of the new Toxicity charge (T-charge for short). The intention of the mayor's T-charge is clear: discourage older, more polluting vehicles from driving into the centre of town, where pollution levels are at their worst. 

This was the second policy introduced by Sadiq Khan to improve air quality in little over two weeks. Earlier this month, the mayor announced his ambitions for London to meet the World Health Organisation (WHO) air quality guidelines for particulate matter by 2030.

This is an ambitious yet crucially important target that no UK politician has previously set out to achieve. It is ambitious because WHO guidelines are more rigorous than those set by the EU – and many of London’s busiest roads currently exceed them. 

I have advocated for many years that key to achieving this aspiration is a reduction in the number of vehicles, both personal and commercial. The T-charge is a step towards achieving this. But if London is going to meet WHO air quality standards, the mayor is going to need to continue to push forward pioneering policies.

The Commission on the Future of London’s Roads and Streets – an independent group of transport and environmental experts – published a report of bold measures to tackle air pollution, traffic congestion and ill health experienced by those that live, work and study in the capital.

Its report neatly outlines the shift from mobility as a product (i.e. the private car) to ‘Mobility as a Service’ that considers how to exploit the potential of new transport technologies, to create seamless end-to-end journeys. For example, an integrated transport information and payment system promises to provide status updates and auto re-routing functions to facilitate travel choices, and ensure journeys are safe, efficient and competitively priced.

The introduction of the T-charge, endorsement of London’s ambitious and quantifiable PM2.5 2030 target and the Commission’s radical recommendations to manage the conflicting pressures on road transport and public realm fall within a few weeks of one another. This bodes well for the capital – If the promises and opportunities can skilfully be harnessed and taken forth with political courage and the necessary investment.

But the problem of air pollution and the need to reappraise our transport systems is not confined to London. The same issues face city dwellers in the UK’s other major urban areas, up and down the country and they should not be left behind.

To this end, the ambition and vision for change in London should trigger action from central and other local governments to give all our major cities the potential to become cleaner, healthier and economically successful places to live, work and visit.

Frank Kelly is a Professor of Environmental Health at King's College London.


To beat rising temperatures, Vienna launches a network of 'Cool Streets'

A Vienna resident cools off at one of the city's new Cool Streets installations. (Courtesy Christian Fürthner/Mobilitätsagentur Wien)

Over the past several months, Austria has recorded its highest unemployment rate since World War II, thanks to the economic aftermath of the Covid-19 pandemic. With no job or a suddenly smaller income – not to mention the continued threat of the virus – many Viennese will opt for a staycation this summer.  

At the same time, last year, Austria’s capital experienced 39 days with temperatures of over 30°C (86°F), one of its hottest summers in history according to the Central Institute for Meteorology and Geodynamics.

Climate experts expect a similarly sizzling 2020 season, and city officials are now doubling down on efforts to combat the heat by launching a “Cool Streets” initiative as well as a new, state-of-the-art cooling park.

“As the city councilwoman in charge of climate, it is my job to ensure local cooling,” Vienna’s deputy mayor Birgit Hebein proclaimed at the opening of one of 22 new “Cool Streets” on 22 June.

“In Austria, there are already more heat deaths than traffic fatalities,” she added.

Hebein was referring to the 766 people the Austrian Agency for Health and Food Security included in its 2018 heat-associated mortality statistics. The number was up by 31% compared to 2017, and in contrast to the 409 people who died in traffic collisions the same year.

The project includes 18 temporary Cool Streets located across the city, plus four roads that will be redesigned permanently and designated as “Cool Streets Plus”.

“The Plus version includes the planting of trees. Brighter surfaces, which reflect less heat, replace asphalt in addition to the installation of shadow or water elements,” said Kathrin Ivancsits, spokeswoman for the city-owned bureau Mobilitätsagentur, which is coordinating the project.

Vienna's seasonal Cool Streets provide shady places to rest and are closed to cars. (Petra Loho for CityMetric)

In addition to mobile shade dispensers and seating possibilities amid more greenery provided by potted plants, each street features a steel column offering drinking water and spray cooling. The temporary Cool Streets will also remain car-free until 20 September.

A sensor in the granite base releases drinking water and pushes it through 34 nozzles whenever the outside temperature reaches 25°C (77°F) . As soon as the ambient temperature drops to 23°C (73°F), the sensor, which operates from 10 a.m. to 8 p.m., turns off the water supply.

The sensors were included in part to allay concerns about legionella, a pathogenic bacteria that can reproduce in water.  

“When the spray stops, the system drains, and therefore no microbial contamination can develop,” said Dr. Hans-Peter Hutter, deputy head of the Department of Environmental Health at the Center for Public Health at Medical University Vienna, in a televised interview.

Hutter also assured the public that there is no increased risk of a Covid-19 infection from the spray as long as people adhere to the one-meter social distance requirement.

But Samer Bagaeen of the University of Kent's School of Architecture and Planning notes that air cooling systems, like the ones used in Germany at abattoirs, have been found recently to be a risk factor for Covid-19 outbreaks.

“The same could be said for spay devices,” he warned.

Vienna’s district councils selected the 22 Cool Street locations with the help of the city’s Urban Heat Vulnerability Index. The map shows where most people suffer from heat by evaluating temperature data, green and water-related infrastructure, and demographic data.

“Urban heat islands can occur when cities replace the natural land cover with dense concentrations of pavement, buildings, and other surfaces that absorb and retain heat,” as the US Environmental Protection Agency states.

A rendering of Vienna's planned park featuring a Coolspot, which is scheduled to open in August. Click to expand.
(Courtesy Carla Lo Landscape Architecture)

Vienna’s sixth district, Mariahilf, is such an area. The construction of the capital’s first “Cooling Park”, a €1 million project covering the 10,600 square-metre Esterházypark, is designed to provide relief. 

Green4Cities, a centre of excellence for green infrastructure in urban areas, designed the park’s main attraction, the “Coolspot”. The nearly 3.40-metre high steel trellis holds three rings equipped with spray nozzles. Textile shading slats, tensioned with steel cables, cover them.

The effects of evaporation and evapotranspiration create a cooler microclimate around the 30 square-metre seating area, alongside other spray spots selectively scattered across the park.

The high-pressure spray also deposits tiny droplets on plant and tree leaves, which stimulates them to sweat even more. All together, these collective measures help to cool their surroundings by up to six degrees.

The landscape architect Carla Lo and her team planned what she calls the “low-tech” park components. “Plants are an essential design element of the Cooling Park,” Lo says. “By unsealing the [soil], we can add new grass, herbaceous beds, and more climate-resistant trees to the existing cultivation”.

Light-coloured, natural stone punctuated by grass seams replaces the old concrete surfaces, and wooden benches meander throughout the park.

Living near the park and yearning for an urban escape close by, Lo says she’s motivated to ensure the park is completed by mid-August.

“If we don't do anything, Vienna will be another eight degrees Celsius hotter in 2050 than it already is,” Hebein said.

Vienna recently came in first in the World's 10 Greenest Cities Index by the consulting agency Resonance.

“There is no one size fits all on how cities respond to urban heat,” says the University of Kent’s Bagaeen, who points out that Vienna was one of the first European cities to set up an Urban Heat Islands Strategic Plan in 2015.

In the short term, prognoses on the city’s future development may be more difficult: Vienna votes this autumn.

Petra Loho is a journalist and photographer based in Austria.