Climate change could shorten the life span of U.S. bridges

Rising seas, heavy precipitation, and extreme heat are causing corrosion, buckling, and cracking.

The U.S. has more than 600,000 bridges, and they’re not made to last forever.

Mahmoud: “They’re designed for a specific amount of time, usually 75 years. That’s a typical design service life for bridges.”

Hussam Mahmoud is a professor in the Department of Civil and Environmental Engineering at Colorado State University.

He says elements of a bridge — from footings and foundations to beams and girders — are expected to deteriorate over time.

And he says climate change can accelerate that process.

Rising seas and heavy precipitation can cause corrosion. Extreme heat can cause materials to expand beyond what they’re designed for — contributing to buckling or cracking.

Increasing carbon pollution can even alter the pH of concrete, causing it to degrade faster.

Mahmoud says in most cases, these risks will not cause a bridge to suddenly collapse.

Mahmoud: “We’re talking about general deterioration over time that we’re able to observe and we’re able to address.”

But he says managing the problem will require more money and resources for inspections and maintenance.

And incorporating data on climate change could help prioritize funding for those bridges in the most urgent need of repairs or replacement.