How extreme heat can impact infrastructure

• Such heat can leave behind devastating consequences on infrastructure, from electricity outages to damaged airport runways and faulty rail lines, per the Fifth National Climate Assessment, a multi-agency effort.
• "We have all this infrastructure that is meant to make us comfortable in the urban area," said Edith de Guzman, a water equity and adaptation policy specialist at the UCLA Luskin Center for Innovation. "But not only is that infrastructure exacerbating the heat, the heat is actually deteriorating that infrastructure."

Zoom in: Extreme heat can impact various types of infrastructure including that of energy, transportation, buildings, water and even digital infrastructure, de Guzman said.

Energy: High temperatures can increase energy demand with more people using air conditioning to cool down. That puts stress on the grid and can lead to brownouts or blackouts.

Transportation: In terms of roadways, heat can soften asphalt which can potentially create safety issues and require more frequent replacement and maintenance. Concrete can expand, crack and buckle.

• For trains, rail made of metal expand and lead to tracks that buckle, which increases derailment risk. Bridges, too, can suffer from expansion of steel.

Building: A lot of materials used, like for roofs and sealant, can degrade faster due to heat.

Water: Underground pipes, including sewer pipes, can expand and shift due to heat, which could cause leaks and breakages.

• Machinery at pumping stations and treatment plants could become overburdened.
• There could also be an impact to water quality because pollutants can be concentrated when then there's less water due to evaporation.

Digital: There's already a very high cooling demand for data centers under regular conditions. Heat makes those data centers more vulnerable to power issues and overheating.

• Equipment such as traffic signals, sensors and telecommunication can also become impacted as they rely on the electrical infrastructure that powers other digital infrastructure.

Zoom out: All infrastructure is designed with some heat exposure in mind through codes, guidelines and regulations, said Mikhail Chester, professor at Arizona State University's School of Sustainable Engineering and the Built Environment.

• But when extreme temperatures exceed that threshold, there are failures that, over time, can start to compromise the integrity of the infrastructure.

Case in point: Roadways that are not designed for the extreme heat may see additional rutting and cracking. After enough cracking, there will start to be potholes from water intrusion.

• "Places like Arizona and Phoenix are more aligned with the extremes that we're currently experiencing," Chester said, adding that other places in the U.S. that are not specifically designed for the extreme heat are more vulnerable.
• But, he added, "nobody's spared from a heat wave and the consequences that it has on infrastructure."

Between the lines: Human-caused climate change is making heat waves more likely and more intense, researchers say.

• "In the past, we've largely had somewhat stable, repeatable climate patterns," Chester said. "But now we're seeing something different."
• Increased temperatures and more frequent heat waves paired with other factors like population growth and aging infrastructure are exacerbating the issue.
• "You've got climate change unfolding on infrastructure that is old and often in need of rehabilitation, and that's not a good dynamic," Chester said.

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