How extreme heat is damaging American transportation infrastructure

Scientists say much of the persistent and dangerous heat blanketing wide swaths of the country is a long-term result of greenhouse gas emissions. Climate scientist Kristina Dahl joins John Yang to discuss how it’s affecting everything from the power grid to trains, planes and automobiles.

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John Yang : What forecasters are calling an extremely dangerous heatwave is persisting in the West. And it’s expected to extend triple digit temperatures to the Midwest and East this weekend. Scientists say much of this heat as a long term result of greenhouse gas emissions, and it’s affecting everything from the power grid to trains, planes and automobiles.

Kristina Dahl is principal climate scientists with a Climate and Energy Program at the Union of Concerned Scientists. Kristina, let’s start by focusing on trains, planes and automobiles, how this heat is affecting transportation and the transportation infrastructure. Can you walk us through the sort of the big effects?

Kristina Dahl, Principal Climate Scientist, Union of Concerned Scientists : Absolutely. Heat affects all of these different types of infrastructure in different ways. For our cars and trucks that are running on asphalt roads, asphalt can deform or buckle when it’s extremely hot, so that can make road transportation difficult.

In terms of railroads, we know that rails can actually deform and buckle as well when it’s hot. Or if there are electric lines that the trains are connecting to overhead, those lines can sag. And that can cause problems for the trains and operators have to slow the trains down.

When it comes to airplanes, there are a few different effects and happen, the tarmac at our airports can deform when it’s hot, which causes problems as planes are trying to take off and land. But hot air also expands and becomes less dense. And that makes it harder for airplanes to get to the level of thrust they need to be able to take off. So when it’s really hot, all of these forms of transportation can be affected.

John Yang : And not only can be affected, but have been affected in years past.

Kristina Dahl : Yeah, many years now, because of climate change. And the fact that it’s making our summers hotter, we see these kinds of instances. Amtrak’s Northeast Corridor line, for example, in the Northeast U.S. has had to slow down train significantly to deal with heat. In recent years, planes have been unable to take off from the airport in Phoenix, Arizona, because of heat, or infrastructure was largely designed for the climate of the past. And that’s not the climate that we’re dealing with today. And it’s certainly not the climate we’re going to be dealing with in the decades ahead because of climate change.

So we’re seeing now that the ways that we’ve designed our infrastructure have some vulnerabilities. And we are going to have to either adapt that infrastructure or our lifestyles to deal with those changes in climate we’ve experienced, or we’re going to have to find ways to redesign and rebuild or develop new materials, so that we can continue to operate our planes, trains and automobiles, the way we’re used to.

John Yang : There’s money in the infrastructure bill, for infrastructures, any of that going to help make this infrastructure more resilient, or perhaps design new plans.

Kristina Dahl : Absolutely. The bipartisan infrastructure laws, a huge influx of money and resources to be upgrading and improving our transportation infrastructure. That’s really important, because we’ve long neglected the maintenance that our infrastructure requires. And so there’s a real backlog in our country. And there’s a lot of upgrading that needs to happen.

And so as companies and states and communities are updating their infrastructure with this influx of money from the bipartisan infrastructure law, the hope is that there’ll be also taking account climate change, so that the infrastructure that we’re investing in now is durable for decades into the future.

John Yang : Are there certain areas or certain populations that are disproportionately affected by the effects of this extreme weather?

Kristina Dahl : Absolutely. So most types of extreme weather hit communities that have long been disadvantaged by racism, discrimination, toxic pollution, extreme heat, is affecting people who live in urban areas without a lot of shade trees that often were the more affordable and more accessible areas for people of color to obtain mortgages, and, but these areas tend to be hotter, and so people are waiting for buses, at bus shelters where there’s no shade, for example.

When we look at coastal infrastructure, a recent analysis by my team found that there are over 1,600 pieces of infrastructure in our country that are at risk from sea level rise, and that more than half of that infrastructure is in communities that are considered disadvantaged because of racism and pollution.

John Yang : You talked about trees providing shade, but do they also help clean the air?

Kristina Dahl : They do. Trees are incredible and it’s what makes green spaces particularly in urban environments really important to be maintaining and to be building as it gets hotter and hotter on our planet.

So trees provide shade, but they also circulate water vapor in the atmosphere. And so that can have a cooling effect in their vicinity. So that’s part of the reason why when we try to mitigate the urban heat island, which is the fact that cities get hotter than the surrounding areas, one of the best ways to mitigate that urban heat island is to plant trees.

John Yang : Every time we do a segment like this, I get mail, saying, weather isn’t climate and climate isn’t weather, but there is a link isn’t there between climate change and the weather we’re experiencing?

Kristina Dahl : Absolutely. So we will always have hot summers and cooler summers. But climate change is shifting our weather patterns so that they are looking different over time. So heat waves like the one the West has been experiencing the last week or so rapid intensification of hurricanes, those sorts of things that are considered extreme weather are becoming more and more likely because of climate change.

John Yang : Kristina Dahl, the Union of Concerned Scientists, thank you very much.

Kristina Dahl : Thanks for having me.