2017 was the third hottest year on record. And based on recent trends, it's not getting cooler any time soon.
Some researchers are asking, how can we stay cool? Especially in our cities.
They're typically hotter than rural areas. But why?
You can thank the urban heat island effect. On hot summer days, roofs, buildings and other urban surfaces can heat up to 90 degrees hotter than the air.
This creates islands of heat. One of the biggest contributors to those islands, dark surfaces.
Dark surfaces absorb all wavelengths of light and converts them to heat. So, the surface gets warm.
It's why your mom told you not to wear black during a heatwave. Surface temperatures can reach up to 150 degrees.
And since asphalt is an insulator, it traps that heat over the course of the day. Then at night when the air is cooler, the heat radiates away.
Lighter surfaces, on the other hand, absorb fewer wavelengths and reflect the rest. That way, all that energy isn't absorbed.
And surface temperatures won't rise as much. So, would coating our streets white help cool down our cities?
