Mamdani’s plan to cool NYC subways

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Here’s a cool story you may have missed: New York City Mayor Zohran Mamdani announced a plan last week to study whether heat from the city’s sweltering subway stations and tunnels can be stored and used to heat buildings during winter. 

“Anyone who has stood in a subway platform in August knows that our stations do not just get hot. They turn into underground saunas,” Mamdani said at a news conference. 

Waste heat from air conditioning units in subway trains drives up temperatures in underground stations, as does other equipment. The heat index in one station has been measured at an inferno-like 130 degrees Fahrenheit.

“The subway pilot will study the use of radiant cooling technology, where a cooling loop runs beneath surfaces in the station, absorbing heat out of the surrounding environment and transferring it into the water,” Inside Climate News explained. “During the summer, some thermal systems can store heat in underground boreholes until winter.”

“Sweltering subway platforms are not just uncomfortable, they are a matter of health and safety,” Louise Yeung, the city’s chief climate officer, told Inside Climate News. “Amidst one of the hottest summers on record, we need no reminder that our aging infrastructure is not keeping pace with our changing climate.”

Meanwhile, in Montana: Yale Climate Connections contributor Karin Kirk shows off her electric vehicle, which was part of an entry for the Drive Electric MT club in the Sweet Pea Festival parade in Bozeman.

– Sara Peach, Editor-in-Chief 

What happened after 13 young people in Hawaii sued over climate change

Bridgett Ennis reports: 

Young people in Hawaii now meet regularly with the state’s Department of Transportation to offer input on public transit, bike lanes, and other strategies to help the department transition away from fossil fuels.

Establishing the Hawai’i Youth Transportation Council was just one of the outcomes of the landmark 2024 settlement of the Navahine v. Hawai‘i DOT lawsuit, which was brought by 13 young plaintiffs. Their lawsuit alleged that the DOT wasn’t making progress toward the climate goals set by the state, violating the plaintiffs’ constitutional right to a clean and healthful environment.

They settled the lawsuit in 2024 before it went to trial, and the DOT is now required to decarbonize transportation by 2045 and, through the youth council, to listen and incorporate the priorities of young Hawaiians.

Yale Climate Connections spoke with Charlotte Madin, who was 12 years old when she became a plaintiff, and Joanna Zeigler, a staff attorney at Our Children’s Trust who led the case.

This interview has been edited and shortened for clarity.

Yale Climate Connections: Charlotte, what got you concerned about climate change in the first place?

Charlotte Madin: The entire time I’ve lived in Hawaii, about eight years now, I’ve noticed the beautiful ocean and the biodiversity of the coral reefs just slowly becoming less and less healthy, which is really challenging to see, especially since both my parents are marine biologists. So seeing that happen in real time in front of me was really scary. And then in 2021, I was on the Big Island when there was a really large fire. There was ash raining from the sky. My grandmother had a concussion and couldn’t get to the hospital because the fire was blocking a route.

YCC: Can you tell me a little bit about what it was like being a plaintiff?

Madin: I wasn’t really sure what was going to be expected of me when I joined the case. But over time it became clear that it was really helpful for me to appear at events surrounding our case to muster support from the community. As for the actual legal dealings, I was deposed by lawyers from the Hawai’i Department of Transportation when I was 13 or 14, which was quite an experience. It was a lot of questions for three or four hours. And so that was probably one of the most defining moments of my career as a plaintiff in this case.

YCC: That must have been very intimidating. What was that like, and what did you do to prepare for that?

Madin: Yeah, it was very intimidating. I remember being really, really nervous for the days leading up to the deposition. But I was told to tell the truth – you know, they won’t be able to find anything wrong with that, take it slow, take a deep breath if you need to, and don’t feel pressured to answer anything. And that advice served me well throughout the deposition. By the end of it, I was exhausted, but I was really happy and proud of what I accomplished and what I’d done.

YCC: Can either of you give me a little bit of an overview of what the lawsuit alleged?

Joanna Zeigler: There were two constitutional provisions that were brought in the lawsuit. The first one is the public trust doctrine, which provides that the state shall conserve and protect Hawaii’s natural beauty and all of its natural resources for the benefit of present and future generations. The second constitutional provision brought in the case was the right to a clean and healthful environment. And that gives each person the right to a clean and healthful environment as defined by the Hawaii statutes.

YCC: How much was the Department of Transportation relying on fossil fuels when this began? And can you put that in the context of any carbon reduction goals or mandates that had already been set prior to this?

Zeigler: The transportation sector is the largest source of greenhouse gas emissions in Hawaii, and transportation emissions are projected to continue to rise. Historically, HDOT’s planning of ground transportation has been very car-centric, prioritizing projects such as road expansion and maintenance rather than projects that reduce greenhouse gas emissions, such as pedestrian, bicycle, and transit expansion and expansion of EV infrastructure. So without breaking that “business-as-usual” planning process of planning for more and more cars on the road, emissions from transportation would continue to be a problem.

YCC: What are some of the major points that the settlement requires the government to do?

Zeigler: The settlement requires HDOT to decarbonize the transportation sector by 2045, which means zero emissions from ground, marine, and interisland air transportation. And the settlement provides benchmarks and requirements for what HDOT needs to do to reach zero emissions.

And one other aspect of the settlement is that HDOT created the youth council. It’s an opportunity for youth from across Hawaii to provide feedback and let HDOT know what their priorities are so that HDOT can take those into consideration when it’s planning and prioritizing projects.

YCC: Is there anything else that either of you wanted to add to help people understand about this?

Madin: Well, I guess a message for the young people out there: You always have a voice, and you always have a choice with how you use that. And utilizing the power of democracy and utilizing the legal system, you can do big things with your voice. So never give up your voice, and don’t let others silence you. Just do what you believe, and everything will work out fine in the end.

Thank you for saving lives this hurricane season

We’re so thankful for your donations during our recent fundraiser. Your contributions will help meteorologists Jeff Masters, Bob Henson, and Irene Sans inform the public about dangerous hurricanes, wildfire smoke, and heat waves this summer and fall. If you’d like to chip in, it’s not too late to support their work!

Your moment of hope

🎙️Utah group aims to make climate-friendly homes the norm

Utah Clean Energy wants to make sure new homes are powered by renewable energy.

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What you need to know about the water crisis in Puerto Rico

U.S. citizens in the San Juan area are waiting hours in line for water.

New Mexico’s clean energy success story

Thanks to your donations, we’re reaching young people on TikTok, Instagram, and YouTube with videos like this one.