Throwing shade: The dark secret of cities that know how to stay cool
It’s Labor Day in the US and many are bidding so long to summer with a long weekend spent outside the city. Reflecting on the past few months, it occurred to me that the season is perhaps unjustly synonymous with sunshine. Visit a stock photo site, type in “summer” and you will see page after page of people frolicking on beaches, near pools, in wildflower-stocked meadows, each blue-sky scene vividly illuminated with sunlight. But there is one aspect of summer that literally dwells in the shadows: shade.
As summer slowly fades from view, it is worth considering this ubiquitous, overlooked quantity – what journalist Sam Bloch, in his new book Shade, calls a “forgotten natural resource.” Wandering the streets of several cities this summer, from the US Pacific Northwest to Europe, I often found myself on treeless, scorched streets – made hotter by reflections from glass buildings and other urban-heat contributors – in constant search of shady protection.
This is widespread, virtually instinctual behaviour. A study by architecture professor Jae Min Lee that examined a number of New York streets in the months of May and June, found that when the temperature exceeded 25C, pedestrians would jump from the sunny side of the street to the shaded one. In contrast to the old jazz standard, life is not always so sweet on the sunny side of the street.
Shade is no mere urban-planning metric, it is the stuff of life. “In Accra, Khartoum and Kinshasa, leafy canopies are the roofs to outdoor rooms where barbers cut hair, hawkers haggle with customers and tea is served,” writes Bloch. “In tropical climates, people naturally prefer to confer, hustle and gossip out of the sun’s permanent glare.” From the toldos (covered awnings) of Seville to the five-foot ways of Singapore and the filigreed architecture of the Australian veranda, people have long sought to preserve the outdoor public realm against otherwise intolerable conditions. In my own garden, a magnolia tree, thankfully planted many decades ago by a previous owner, provides us a place to gather even on the hottest days. It brings to mind the old proverb about “old men planting trees whose shade they know that they will never sit in.”
Apart from comfort – tree shade can lower temperatures by some 19C – shade provides beauty. In a sculptural series of work called Escaping Flatland, Edward Tufte arrayed stainless-steel forms in a field enclosed by woods to reflect the “borrowed”, always changing, light. We might think of this the next time we are reading under a shady tree on a park bench in London or eating lunch under a pergola in Greece.
These days, many locations are experiencing conditions that might be deemed tropical. Along with all the other social chasms – the income gap, the digital divide – a new fault between the cooked and the cooled is emerging. While some places bask in or above the 30 per cent of tree cover set as an ideal threshold for reducing the urban heat-island effect, others are shade deserts. In Detroit, for example, one analysis found that more than 90 per cent of the city’s bus stops (serving nearly 100,000 riders daily) had poor shade. Apart from the health risks, this lack of shade informs the very way that we experience the world. In one study, bus-stop users who waited in the shade of mature trees underestimated how long they waited for the bus (in the sun, the effect was reversed). Planting trees and building verandas are highly effective and relatively inexpensive ways of making life a little more comfortable and equitable for city dwellers.
Tom Vanderbilt is a regular Monocle contributor. For more opinion, analysis and insight, subscribe to Monocle today.
