Climate change is not just happening at a global level. Some activities at a regional and even local level impact temperatures.

“If we’re focusing only on decreasing emissions of greenhouse gasses and ignoring the way we build our cities, we’re potentially missing half of the actual impact,” said Matei Georgescu, Arizona State University urban planning professor.

The way we build cities, how tall, how spread out they are and even the color and materials used in roofing, all affect a city’s daily climate, said Georgescu, who studies the “urban heat island” effect as one of many factors affecting climate, especially in highly urban areas like Phoenix.

“Urban areas essentially modify the way energy is received from the sun and trap this energy within the urban canopy during the evening and nighttime hours and so therefore urban areas prevent the normal nighttime cooling that happens over rural areas,” Georgescu said.

Georgescu has tested the Phoenix metro area and said using the air conditioner inside during heat waves increased the temperature outside.