How Can Cities Reduce the "Heat Island" They Create?
More than 20,000 high-temperature records have been broken so far this year in the United States. And the heat is especially bad in cities, which are heating up about twice as fast as the rest of the planet.
High temperatures increase the risk of everything from asthma to allergies, and can even be deadly. But a researcher in Atlanta also sees this urban heat wave as an opportunity to do something about our warming planet.
The story starts at Ebenezer Baptist Church, arguably the most famous place in Atlanta; it was Martin Luther King Jr.'s church and the heart of the civil rights movement.
It's now playing an unexpected role in a new movement: the struggle against rapidly rising urban temperatures. Cities are literally global hot spots.
Brian Stone Jr., director of the Urban Climate Lab at Georgia Tech, leads us into a huge green space, spanning two full urban blocks, which Ebenezer Baptist leases out as a community garden.
"The impetus for this was to have local food production, as we see in a lot of communities," Stone says. "But the centralization of this, literally less than a mile from downtown Atlanta, is unique."
And it's not simply a garden. It's a summer camp at the moment, and an urban farm brimming with okra, onions, tomatoes and arugula, among other vegetables.
It's an island of calm that actually helps offset some of the heat that builds up so dramatically in the concrete all around us. That's not to say it's actually cool on a midsummer day.
"You know, it feels good here," says Amakiasu Ford-Howze, who works at the garden. "People come here and they go, 'Ah,' because you do see green, and you see flowers. We have a lot of flowers. So it just feels good here. It helps."
Stone says it actually accomplishes much more than meets the eye. Open, vegetated space like this helps water evaporate throughout the day. And evaporating water carries away heat. Like sweat, it's nature's air conditioning, but we've managed to interrupt that process in cities. The result is called the urban heat island effect, and it's adding to our warming woes.
"In addition to having increasing concentrations of greenhouse gases globally, which are driving warming at the global scale, at the scale of cities, we have changes in land use that are also contributing to rising temperatures," Stone says.
Cutting down trees is a big factor. Pavement also stores heat during the day and makes cities hotter at night. And as cities heat up, air conditioners run harder. Their exhaust heat also pushes up the temperature. It all adds up — a lot — according to Stone's research on American cities.
City Heat via Shutterstock.
Read more at NPR.