Standing in a parking lot on a hot summer day, you can feel the heat radiating off the black pavement.

Hoffman: “These large expanses of human landscapes that are traditionally built with things like cement, asphalt, bricks … they actually absorb more of the sun’s energy and then re-emit it back into the air as heat throughout the day and into the evening.”

Jeremy Hoffman is a climate and earth scientist at the Science Museum of Virginia. He says this phenomenon, called the urban heat island effect, can cause dramatically hotter temperatures in some areas.

Hoffman: “Our work has shown in Richmond a difference of up to 16 degrees Fahrenheit between the coolest and warmest place at the exact same time, so it’s a really big difference – all brought about by the kinds of land uses that we make in our cities.”

And it contributes to health problems. In Richmond’s hottest areas, Hoffman found higher rates of heat-related illnesses. And yet many people who live there …

Hoffman: “Using census data, we know that they just maybe don’t have the same kind of income that would allow them to use things like air conditioning.”

As summers get hotter, these health risks are likely to increase. So adding green space and shade trees to cities can provide cooling and protect the health of vulnerable people.

Reporting credit: ChavoBart Digital Media.