Not a paradise in the sun: the growing danger of urban heat islands

It might be a bit premature to start worrying about #heatwaves in western #cities just after the spring equinox but, based on recent history, the role that so-called urban heat islands (#UHI) play in making cities #unsustainably hot will be news before long.

Given the seemingly ceaseless rain that Europe — and the UK in particular — endured in February, it’s hard to remember just how hot conditions were in cities just two years ago. According to Copernicus, the EU’s earth observation unit, 2022 was the second hottest year on record in Europe with summer temperatures in Europe at 1.4 deg C above average.

According to one academic calculation, soaring temperatures in that year may have been responsible for 70,000 excess deaths in Europe. In Italy, the authorities issued red extreme heat warnings for 16 cities across the country. In the UK, a wildfire in Wennington, east London destroyed almost 20 houses.

A study into more than 850 European cities with populations of more than 50,000 — and which found London and Paris as recording the most heat-related deaths over the 20 years to end of 2019 — identified urban heat islands as a contributory cause.

This phenomenon is created by the dark-coloured, human-made materials such as bitumen used on roads and in buildings absorbing and storing heat during the day which is then released at night, helping to keep temperatures uncomfortably hot during the night time hours. Residents experience higher temperatures than surrounding rural areas, thus the phenomenon’s name. Meanwhile urbanisation often leads to the loss of green spaces that would offset that impact by cooling the city.

Climate injustice

This climate impact is also one of environmental injustice. According to the World Bank, low-income communities, neighbourhoods bereft of green spaces and other marginalised populations bear a “disproportionate burden” of the economic costs associated with urban heat. It also creates a climate doom loop as the extra energy needed to power air conditioning needed to make homes and workplaces inhabitable adds to greenhouse gas emissions that cause climate change.

Many cities are not prepared to cope with a much warmer climate and will need help to harness both financial and knowledge resources to enact solutions to help cool their urban environments.

One city that has been leading the challenge is Singapore, whose Green Plan 2030 has set “concrete targets” (no pun intended, presumably) to plant 1 million extra trees, develop over 130 hectares of new parks, and ensure every household is within a 10-minute walk of a park.

Last year it hosted a “deep-dive on urban heat” as part of the World Bank’s Global Platform for Sustainable Cities. It focused on incorporating climate adaptation and cooling solutions into planning, as well as policy and regulatory frameworks for implementation and approaches to financing.

The good news is that the debate is at least underway. Earlier this year, parliamentarians in London, who found that urban temperatures can be up to 8 deg C warmer than surrounding rural areas, recommended nature-based solutions such as parks, trees, water bodies and green infrastructure — including green roofs —as ways to deliver significant cooling effects.

As city families start to plan their holidays to an island in the sun, they should bear in mind that home could soon be a less pleasant island of its own.

Low traffic neighbourhoods get academic approval: green light for a tool to create sustainable cities

Independent academic experts have found that controversial low traffic neighbourhoods (LTNs) in outer London deliver massive health benefits that far outweigh the investment costs. Hopefully this should settle the issue for good.

Just eight months ago, the writing appeared to be on the wall for local government schemes that limited motorists’ freedom — perhaps done by an angry spray-can wielding opponent. The Conservatives had scored a lone and unexpected parliamentary by election victory in Uxbridge and South Ruislip in west London.

The victor had claimed it was a sign of opposition to London Mayor Sadiq Khan’s ultra low emissions zone (Ulez) that imposed penalties on high-emitting vehicles and which had just been extended to the local borough, Hillingdon, Labour leader Sir Keir Starmer appeared to agree, saying that the local party was doing “something very wrong”.

At the same time there was increased and often violent opposition to LTNs, schemes where motor vehicle traffic in residential streets is greatly reduced by erecting bollards and restrictions enforced by cameras. Opponents vandalised the cameras and tried to destroy or neutralise the bollards. The right-leaning press picked up on the protests as another “woke” agenda conflict.

Two-point turn?

But since then, the feeling of a turning point has dissipated, and advocates are confident that both interventions are becoming accepted in communities. Khan’s office came out with data showing that harmful pollution emissions had reduced by 26 per cent within the expanded Ulez area — compared with what they would have been without the Ulez coming into force.

The feeling has been bolstered by a six year study of the impacts of “active travel infrastructure” in three of the capital’s outer boroughs: Enfield, Kingston and Waltham Forest.

The work led by Professor Rachel Aldred of Westminster university and carried out with academics at Cambridge university and another London college found that the 50 or so schemes had generated more than £1 billion worth of health benefits for a cost of £100 million — a 10-fold return on investment.

It calculated an estimated average benefit of just over £4,800 per adult aged 20–80 due to increased physical activity. They compared that to an estimated cost per person of around £112 for higher-quality LTNs or £27–£35 for lower-cost versions.

One reason was that two years after the schemes’ implementation, there was a doubling in the amount of time spent on active travel — walking or cycling — and a 30 per cent decline in car use.

It is the not the first study to identify positive impacts. In 2022 a team at Imperial College London found that LTNs in the brough of Islington reduced traffic and air pollution without displacing the problem to nearby streets. The researchers found that concentrations of nitrogen dioxide fell by 5.7 per cent within the LTNs and by just under 9 per cent on their boundaries, compared to the “control” i.e., non-LTN sites, some distance away.

Another study identified potential benefits in terms of safety. Researchers found that introducing LTNs, this time in the inner London borough of Southwark, led to a decrease traffic speeds and

volumes. Again, traffic volumes on boundary streets did not increase in most neighbourhoods.

Back to Ulez and one study late last year found that it had significantly improved air quality, benefitting Londoners’ physical and mental health. Among other benefits researchers at the University of Bath found an improvement in general health levels, a reduction in both hospital admissions for respiratory issues and in prescription costs for those ailments.

Beyond the election

But academic research goes only so far, especially in a likely election year. Media outlets critical of these sustainability measures have already launched attacks on both Ulez and LTNs. The Conservatives have already sought to make it a woke issue, attacking the “sinister” misuse of the 15-minute city — the idea that everything a person needs should be within a quarter of an hour's walk or cycle from any point in their neighbourhood.

But if academic researchers have identified benefits, it is likely that people living in or near the areas will have experienced those improvements first-hand. Criticisms of the projects, such as the idea that they increase air pollution on nearby roads, can be debunked. It will not be a smooth journey but LTNs and schemes such as Ulez are here to stay.

From soup to soap opera: how art is bringing climate change to a new audience

Protestors throwing soup at Van Gogh’s paintings or defacing Andy Warhol's soup cans have made art an urban climate change event. Now a new exhibition of images of human climate destruction may ask tougher questions.

As the climate emergency worsens, many of us feel we are seeing more frequent representations of the worst outcomes in popular media such as film, music and visual art. Recently protestors have targeted priceless works of art held in major cities’ galleries to call attention to the climate crisis.

Some commentators say the interventions are themselves a kind of protest art. In other words, the vandalism is a way of rehearsing the destruction of what we cherish as most beautiful and most worthy of preservation.

The protests come at a time when art is really being increasingly used as a tool by artists to communicate and respond to climate change. It may be that more artists are drawn to the crisis, but it is equally likely that the average person is more likely to notice it right now — and that artists have been focused on nature, climate and the environment for decades.

The breathtaking photographs taken by Edward Burtynsky over his 40-year career that are on display at London's Saatchi Gallery until early May this year are the latest to attract headlines. That attention is utterly deserved as his images are both astonishing in their own right but at the same reveal some of the implications of our globalised and industrialised patterns of production, transport, trade and consumption.

Whether it is a winding river of polluted water or almost perfect conical giant piles of coal in China, the images may provoke anger among viewers, but should also force them to question their role in supporting the polluting activity through their purchasing decisions.

But this not a new phenomenon. There is a clue in Burtynsky's CV — now aged 69 he has been recording industrialisation and its impacts on nature and the collective human existence for more than four decades. LS Lowry was depicting the human side of industrial life in northwest England in the mid-20th century. Indeed, a print that has hung on my wall for 30 years, by the Austrian visual artist and architect Friedensreich Hundertwasser, is a reminder that art as a climate campaign medium has been around for many years.

Give art a chance

The important question is whether art can be an effective medium to communicate messages about climate change to the viewing or listening public. Academic research has shown that when people are confronted with climate art, that tends to lead to increased support for climate-friendly policies. Interestingly the authors found that the emotional response might be easier to achieve if the art does not try to claim to be the truth about climate change but instead just raises the topics and leaves it up to the viewers to come to their own interpretation.

The climate protestors are clearly framing the whole debate around the need of people to take climate change seriously, while Burtynsky has shared images with us, allowing people to draw their own conclusions. The researchers might be right that the latter is more effective; indeed Aesop’s fable about the battle between the Sun and the North Wind to get the traveller to abandon his coat comes to mind.

The recent emergence of climate change as a story line in the BBC Radio 4 soap operate The Archers is another example of the potential of placing the idea in front of viewers or listeners and let them decide on the merits of the fictional example.

Art can also be used as a way of tracking past changes in climate patterns. There is a huge reliance on scientific data as the key lens through which to prove and display long-term changes in climatic patterns. However, academics are now keen to highlight the role that information such as diaries can play in tracking those changes.

Art fits into that latter pattern. An article in the Journal of Art in Society argues that the range of animals depicted in prehistoric paintings gives pointers to the nature of the climate at the time, while drawings of glaciers in the mid-19th century provide a “useful benchmark” against which more recent glacial retreats can be measured.

Some cynics might say that art can only ever entertain rather than promote actual change. But given the parlous record of politicians, policymakers and scientists in moving the world towards action is reason enough to say “give art a chance”.