A temperate climate is important to just about everyone. Although we all have our own preferences, the temperatures that most find pleasant actually fall within a very small, predictable range. This means even the slightest change to average temperatures can have a very large impact on a population, especially in a city. It’s easy to forget that our bodies evolved over thousands of years to be climatized to a specific range of temperatures and conditions. Urban Heat Island –
This disruption is what concerns climatologists so much about man-made climate change. It’s impact is global, causing everything from glacial melt to rising sea levels. However, it has a unique impact on cities and urban areas. The increased temperatures produce urban heat islands that can do significant damage to the area’s surrounding ecology. Let’s explore exactly what an urban heat island is and what can make it so dangerous.
What is an Urban Heat Island?
An urban heat island is a metropolitan area that, due to human activity, is significantly warmer than its surroundings. The temperature difference is often greater at night than during the day, as well as when wind levels are weaker. Their primary cause comes from the modification of land surfaces that occurs in metropolitan cities. Urban waste and pollution also contribute to heat islands and affect the weather and surrounding climate conditions. For example, suburban areas around urban heat islands often experience more rainfall than the heat island itself.
Urban heat islands have very negative impacts on the environment. They worsen the air quality due to pollutants like ground-level ozone and the water quality due to warm city water that flows into nearby local streams and upsets the ecosystems in that area. These negative effects have led many cities to try to mitigate these harmful environmental impacts. Some municipal governments have invested in the creation of green roofs, which entails planting gardens on the rooftops of cities. Others have added lighter colors to their urban design and architecture, which reflects more sunlight and thus has a cooling effect.
The Reality of Urban Heat Islands in the US
On average, extreme heat kills more people in the US today than any other weather hazard. The CDC estimates that roughly 700 people die each year from heat-related illnesses. Disadvantaged communities, who don’t have the resources to install air conditioners or buy cooling systems, are most at risk. Urban heat islands can lead to city populations overheating indoors, which is where the majority of heat-related deaths or injuries occur.
New York City, for example, is a major urban heat island. The city government is currently taking steps to lower urban temperatures, acknowledging that one of the main causes of its urban heat island is the man-made materials that have been used to construct buildings, roads, and other structures throughout the city. The government is responding by trying to reduce its use of heat-causing materials, which it hopes will lower temperatures.
What is Temperature Mapping?
The bulk of New York City’s plan revolves around analyzing temperature mapping data to uncover particular hot spots. These models also include data that show the areas with the largest number of communities with comorbidities that are most at risk for heat-related illnesses. These models are used not only in New York City, but also by other city governments around the country. The reason temperature mapping is so essential is because it gives urban planners specific insights into the highest-risk hotspots of certain neighborhoods.
Temperature mapping can indicate where it makes the most sense to build parks, since parks with substantial amounts of trees noticeably lower temperatures in that area. It also highlights how coastal regions near water are normally quite a bit cooler. The Lower East Side in Manhattan, for example, was shown by temperature mapping to be substantially cooler than many experts predicted, likely due to the nearby water of the East River.
In order to create temperature mapping models, experts often use data loggers. Data loggers are electronic devices that collect environmental data. These data loggers measure and record temperatures in a specific region at regular time intervals. This data can then be internally stored, optimized, and transferred to external computers or cloud storage, where it gets analyzed by software. Multiple data loggers can be used to record temperature data from different areas in a city, and software can use this data to create temperature maps. According to Dickson Data, temperature mapping is crucial not just for mitigating urban heat islands, but also for providing useful data to industries like big pharma, aerospace, and agriculture.
Solutions for the Effects of Urban Heat Islands
Based on temperature mapping data, urban planners can decide where the creation of local gardens, green roofs, parks, and trees makes the most strategic sense. Prioritizing what policymakers call heat equity will become increasingly important as the effects of climate change continue to compound. Energy-efficient appliances are being actively encouraged by many city governments as a way to cut down on power consumption. Measures to incentivize energy saving are also proving effective, such as making a city more bicycle-friendly to cut down on CO2 emissions from cars.
Cool roofs can also be used to lower temperatures in cities. An alternative to green roofs, cool roofs use special materials to reflect sunlight away from the city. One study found that cool roofs can provide annual energy savings of up to 50 US cents per square foot. Cool roofs can also reduce greenhouse gas emissions and improve air quality in cities. They can serve as an important piece of renewable energy initiatives in many cities.
Urban heat islands remain an unacknowledged problem by many people outside of the urban planning and climate science communities. However, it has real consequences for vulnerable communities in urban areas. As climate change continues, urban heat islands will continue to grow in priority for city governments looking for creative solutions for their residents and infrastructure.