Extreme Temperatures: How North American Cities Amplify Climate Change

Cities are getting hotter not only because of climate change, but how we develop more buildings and asphalt, more waste heat from vehicles and buildings, HVAC systems, less trees, less vegetation. All of this results in our urban environments being up to 10 degrees hotter than the surrounding natural areas. Welcome to Sustainability Leaders. I'm Michael Torrance, Chief Sustainability Officer with BIMO Financial Group. On this show, we will talk with leading sustainability practitioners from the corporate, investor, academic, and NGO communities to explore how this rapidly evolving field of sustainability is impacting global investment, business practices, and our world. The views expressed here are those of the participants and not those of Bank of Montreal, its affiliates, or subsidiaries. Hi there. My name is George Sutherland from the BIMO Climate Institute. In today's episode of Sustainability Leaders, we'll be talking about trends in extreme heat and their intersection with our social and economic systems, as well as the actions that people, communities, and governments can take to help mitigate these impacts. While temperatures may be starting to cool in the northern hemisphere autumn, a retrospective look at this past summer shows that it was the warmest on record, and with these elevated temperatures come more frequent and severe heat waves. To help me unpack this, I am joined by Jane Gilbert, Chief Heat Officer for Miami-Dade County. Jane was the first Chief Heat Officer named globally and is one of the few people to hold this title. Thank you for joining me, Jane. It's a pleasure. Now the title of Chief Heat Officer is likely new to many, so to begin our discussion, could you describe what the responsibilities are for a Chief Heat Officer? Yes, of course. When Mayor Danielle Al-Levin Cava, the Mayor of Miami-Dade County, appointed me in May of 2021, so about two and a half years ago, she charged me with addressing the increasing health and economic impacts of rising temperatures here in Miami-Dade County. We've looked at vulnerability assessment of who's most impacted and then engaged wide range of stakeholders in the development of our action plan. Now we're in heavy implementation mode of that plan. That sounds like a broad mandate with a focus on building resilience to extreme heat. To that point, what are the current trends that you've observed related to extreme heat? So we're coming off an unprecedented hot summer, but historically our trend from say 1985 has been an average minimum temperature increase of about 2.2 degrees Fahrenheit or a degree centigrade. But this past summer, we just had dramatic increase like 10 times the number of extreme caution days. And those we define here in Miami as days with a heat index at or above 105 degrees Fahrenheit, which is a little over 40 degrees Celsius. And historically, just in the last 14 years with climate change baked in, we've had about six days out of the year where we've hit those heat indices of 105 or more or 40 degrees Celsius or more. This past summer, we had over 60 days with a heat index over 105 or more. So over 10 times the number of extreme caution days. And why are these trends particularly concerning for people who live in cities? So cities are getting hotter not only because of climate change, but how we develop. So more buildings and asphalt, more waste heat from vehicles and buildings, HVAC systems, less trees, less vegetation, all of this results in our urban environments being up to 10 degrees hotter than the surrounding natural areas. And it's very unequal. So we have certain areas with 40% tree canopy that are much cooler in those tend to be higher income areas. And then we have areas with less than 10% tree canopy and those tend to be our lower income, more vulnerable populations that are living there. They're having to pay more to keep their homes cool. It's oppressive to walk and wait at a bus stop and they can't afford to be in an AC car. So these are the areas that we need to double down our investments. And listeners may be familiar with the term of the urban heat island effect, which you're referring to. This is the idea that due to the concrete and the asphalt surfaces as well as heat output from vehicles and buildings and also the corresponding loss in natural spaces, cities tend to be hotter than the surrounding countryside. Yes. Now more than half of the world's population lives in cities. And as a result of that, most of the world's economic activity is also concentrated in cities. And we see that at the same time cities are expected to grow larger with continued trends in urbanization while they're also simultaneously projected to get hotter as climate changes locally intensified in cities by the urban heat island effect. So it strikes me that there are some important economic implications associated with this. And I wonder if you could speak to what some of those economic or financial impacts of extreme heat can be? Yes. One of the largest economic impacts that we're feeling right now is lost labor productivity due to extreme temperatures. Organization, the Adrian Ars Rock-Fehler Foundation Resilience Center did a study of globally some of the impacts due to labor productivity loss alone, the economic impacts and looked at 12 cities globally, including the Miami metropolitan area. And they found that we are currently experiencing about $10 billion economic impact due to high temperatures causing lost labor productivity, lost time on the job. And that is projected to double by mid-century to $20 billion a year. So these are substantial economic impacts and layered on top of that are also the social costs of extreme heat. Could you speak to this as well? So I started to talk a little bit earlier about the difficulty people can have with staying cool at home affordably. That is a big piece. Our lower income populations, a large group of them are paying very high utility costs just to stay cool or they're having to opt to not turn on the AC and then put themselves in their families in harm's way with the levels of heat. And so it's a difficult choice they're making. We also have over 300,000 outdoor workers in Miami-Dade County that are increasingly exposed to those high temperatures. In other words, those 105 degree temperature days that are getting more intense as we get hotter. So that's another impact people that get to work by public transit and walking that are we've had people end up in the emergency room because they had to wait at a bus stop that was unshaded for too long. So all of these are and then there's just quality of life changes, right? Kids in summer camp can't be outside as much or parents can't take their kids to the playground. It's in all times a day and times a year. So those are some definite quality life impacts as well. And you've touched on this earlier but just one pack in further detail. You mentioned that urban spaces aren't created equally. So what does this mean for how extreme heat is experienced across cities and what inequities exist? Yeah, so when we did our vulnerability assessment for Miami-Dade County, I really wanted to understand what populations were having the highest rates of heat-related illnesses and where those were. And so we looked at heat-related emergency department visits and hospitalizations by zip code. And we have great disparity. We have some zip codes with four and five times the rate of heat-related emergency department visits and hospitalizations and others of codes in Miami-Dade County. And the top correlating factors are high poverty rates, high land surface temperatures, so are urban heat islands, and high percentage of outdoor workers. So people living in these low-tree canopied, high-ass vaults, dense areas are really suffering more from this significantly. We also partnered with our university partners on placing sensors in different areas of the county and they too found that when the national weather surface is projecting a certain temperature based on say the forecasting at the Miami International Airport, there are other neighborhoods that could be experiencing up to 10 degrees higher temperature than that and not be aware that it's actually extremely dangerous where they are. And this drives home what we already know, which is that the transition to a low-carbon future must be inclusive. So what is required to make urban spaces more resilient to heat extremes while ensuring that this is achieved in an equitable and an inclusive manner? Yes, so there are two big interventions that we're investing in that both address helping low-income people adapt to extreme heat, but also address our low carbon future. So one is to increase our investments in home weatherization programs and energy efficient retrofits and making sure that we're providing not only passive but active highly efficient cooling retrofits for people's homes so that they can bring their utility costs down. We can bring our greenhouse gas emissions down at the same time. The other area is doubling down on tree planting and tree preservation efforts in our areas with less than 20% tree canopy and greater than 20% poverty rates. 90% of our investments last year. We increased our funding last year by 2.5 million. We're increasing it again this year to 3 million so we've been increasing each year and we just got a 10 million dollar inflation reduction grant for the next five years. So we're doubling down on our tree canopy enhancement particularly in these urban heat island areas. So both those tree planting and those energy efficient retrofits really help all of us transition right to that cleaner energy economy and to address our urban heat island. And what type of initiatives has Miami-Dade County implemented to advance this? Yeah so our plan has three main goal areas. One is to inform and prepare people. So we declared May 1 through October 31 as an official heat season and our goal is to raise public awareness on the level that Miami-Dade County has raised public awareness and preparedness around hurricanes. And so we've done bus shelter bus stop ads particularly in the zip codes with the highest rates of heat related illnesses, radio spots, television, social media, but also trained community disaster volunteers trained summer camp providers trained or cooling site staff and partnered with the healthcare community on enhancing the healthcare practitioners understanding of how to look at how chronic high heat exposure can exacerbate other existing conditions and make sure they're asking the right questions and coding those illnesses correctly. So a lot of training and outreach that's the first goal area. Also in that is to work towards protecting our outdoor workers. So we held three trainings with four employers to put in health safety plans. In the United States the Occupational Safety and Health Administration is in the process of creating a heat safety standard but right now they don't have one. So there's only guidelines. So we're working towards potentially having an official heat standard for Miami-Dade County. That's another policy we're working on. Certainly we've updated the policy for all our own county workers and are rolling out those trainings and making sure that all our workers under our care are protected from that heat. So that's all within that first goal area. The second one is to help people cool their homes and so we talked a little bit about upping weather, visualization programs, multifamily retrofits but also to make sure that our cooling sites have backup power and can operate in the event of a widespread power average. Then last is that tree canopy and that urban heat island mitigation. So in addition to all the tree planting that I mentioned earlier we're going to be piloting cool pavements and looking at enhancing our access to drinking water and water features more broadly in the public realm. You mentioned cool pavement as one of the solutions. Could you share a bit more on how this is being applied? Sure. So cool pavement is a pavement that has what's called a high albedo, a high reflectivity just like cool roofs. Cool roofs we already have a requirement in Miami-Dade County that all low-slope roofs have to meet a certain albedo level. It's similar although it's not as standardized as the cool roofs. In other words it hasn't been as well tested out there, LA and Phoenix have done, rolled out pretty strong cool pavement, pilots and programs and we're looking to do some of the same to understand where does that work well, how well does it stay up over time maintained over time because a white pavement can get pretty dirty over time and so we're looking and piloting it but it has been shown to be able to reduce urban heat island effect. And are there examples of other cities that are leading through action? Oh absolutely there are a lot. In fact I now have seven or eight other chief heat officers around the globe that I get to interact with on an ongoing basis but even beyond that there are cities like Boston or Tucson, Arizona or or Austin, Texas that I've interacted with that have been doing great work on heat without a chief heat officer. So and even in Canada I've interacted with some folks up in Canada interested in learning more about what we're doing here and acting on initiating their own heat action plans. And is action only limited to governments or are there also things that homeowners or communities can do to help protect themselves against extreme heat? Oh absolutely there's we need all hands on deck to address these issues. So as individuals we can protect we can learn how to note how to protect ourselves, our loved ones, our workers from the impacts of extreme heat and make sure that we take those precautions. As homeowners we can retrofit our homes to make them highly efficient and bring down both the costs but the emissions that are associated with those homes and certainly in our neighborhoods to advocate for more trees less pavement, ideally native plantings that can preserve the habitat, help absorb stormwater and filter the stormwater in addition to cooling down the neighborhood. What resources can people explore to learn more? I think the Biden administration has put together a very effective website is called heat.gov. So I encourage people to take a look at that and then the R. Struck Resilience Center created an extreme heat action platform for local governments that are looking to create their own action plans. It's sort of a primer on how to do that. And we'll include links for those resources in the show notes. Lastly in a few weeks world leaders will be gathered at COP28 and Dubai to negotiate progress on global climate goals. What are you watching for and hoping to see come out of this meeting? So some of the most powerful agreements that have come out of previous cops have been at this subnational level led by cities. And cities are, as you mentioned at the beginning of this interview, the drivers of population growth and economics and greenhouse gas emissions. So we have the potential to really address issues at that level. So I would hope that a coalition of subnational governments get together and commit to addressing urban heat islands through also means that will bring down greenhouse gas emissions from the built environment and from the transportation sector as well as investing in nature-based solutions in tree canopy. And so that's what I would really like to see from COP28. Well, Jane, thank you very much for joining me to discuss trends in extreme heat, how this intersects with our urban environment and what can be done to mitigate these impacts. Well, it was my pleasure, George. That's Jane Gilbert, Chief Heat Officer for Miami-Gade County. Stay tuned for more episodes of sustainability leaders where we will host leading experts and continue to explore the impacts of climate change on our social, financial, and natural systems. Thanks for listening to Sustainability Leaders. This podcast is presented by BMO Financial Group. To access all the resources we discussed in today's episode and to see our other podcasts, visit us at BMO.com/SustainabilityLeaders. You can listen and subscribe free to our show on Apple Podcasts, where your favorite podcast provider and will greatly appreciate a rating and review in any feedback that you might have. Our show and resources are produced with support from BMO's marketing team and puddle creative. Until next time, I'm Michael Torrance. Have a great week. For BMO Disclosures, please visit BMOcm.com/podcast/disclaimer.