Cooling Our Cities
March 29, 2023
Cities offer prime opportunities for employment, education and entertainment. That may be why more of the world’s population is ending up in them. About 56 percent of all people on the planet live in cities, and that number could grow to 68 percent by 2050. Some megacities, like Tokyo and Mumbai, each could top more than 30 million individuals within 30 years.
But urbanization is creating environmental problems. Cities are a major source of air, land and water pollution, and generate over 70 percent of the gases that cause global warming. Traffic congestion, constant construction, powering all those lights and other typical activities require vast amounts of energy. Despite progress with renewables, most of that power still comes from carbon-based sources that pollute the air and contribute to climate change.
Beyond environmental damage, these emissions are contributing to rising incidences of pulmonary diseases in urban centers. Air pollution exacerbates conditions like asthma, bronchitis and COPD, causing millions of premature deaths around the world every year. In the United States, the Environmental Protection Agency estimates that excess heat claims about 1,300 lives per year. This is partly attributable to the “urban heat island” effect, a phenomenon that causes city temperatures to be warmer than surrounding areas as a result of human activity.
The rise of cool tech
The good news is that scientists and other innovators are developing breakthroughs that can make city life healthier, greener and cooler. Increasingly, such individuals can be found at private-sector organizations that are putting sustainability on par with profits to meet the evolving demands of customers, shareholders, employees and other stakeholders. One such company is Saint Paul, Minn.-based 3M, which has adopted a three-pronged sustainability framework: Science for Circular, Science for Climate and Science for Community.
“At 3M, sustainability really is at the core of our company,” said Carrie Niezgocki, marketing operations manager, Safety & Industrial Business Group, 3M. “As we’re developing products and solutions, we need to show a Sustainability Value Commitment. It’s our company requirement that every product needs to demonstrate how it is impacting the greater good.”
Some 3M innovations offer hope for urban areas looking to reduce air pollution and offset the urban heat island effect. For example, the company’s Cool Roofing Granules for residential homes are solar reflective, redirecting heat and sunlight that other shingles would absorb. Available in multiple colors, they are widely used in communities such as Los Angeles — where a local regulation known as the Cool Roof ordinance requires the use of reflective surfaces.
Some 3M innovations offer hope for urban areas looking to reduce air pollution and offset the urban heat island effect. For example, the company’s Cool Roofing Granules for residential homes are solar reflective, redirecting heat and sunlight that other shingles would absorb. Available in multiple colors, they are widely used in communities such as Los Angeles — where a local regulation known as the Cool Roof ordinance requires the use of reflective surfaces.
3M™ Cool Roofing Granules feature a highly reflective, colored ceramic coating over a raw, base mineral. “What we’ve learned is that if the urban heat island can be taken down just 1 or 2 degrees, it can save lives during an extreme heat event,” said Niezgocki, who spoke via a video presentation at a recent Washington Post Live event.
Shingles that use 3M’s Cool Roofing Granules can meet California’s Title 24 building code. “In our roofing business, we’re interested in how we address climate issues in communities,” said Niezgocki. “And also meeting the demand of consumers, who are looking for more eco-friendly materials in their choices.”
“Shingles are the most widely used materials on homes across the country, so we were able to transform that into a smog-fighting surface.”
3M also has developed roofing granules that pull smog from the air and convert it to plant-usable nitrogen. “Shingles are the most widely used materials on homes across the country, so we were able to transform that into a smog-fighting surface,” said Niezgocki. “It’s similar to planting two to three trees.”
Solar rays activate 3M™’s Smog-reducing Granules to transform smog into water-soluble ions. The granules are used in roofing products manufactured by the company’s partners in the construction trades, including Oregon-based Malarkey Roofing Products and Atlas Roofing Corporation, based in Atlanta, Georgia. “We’re working with our customers [and] collaborating on unique solutions, as well as continuing our research with consumers,” said Niezgocki. “One of my favorite sayings in working with our R&D team when we’re looking at a problem we’re trying to solve, or evaluating an opportunity, is … ‘That hasn’t been invented yet,’ and ‘yet’ really is that jumping off point for where the innovation begins.”
Policies for progress
From a policy perspective, 3M believes more jurisdictions should require the use of building materials that promote positive environmental impacts and mitigate the climate effects of urbanization. “We’ve seen success with infrastructure policies, like with the city of L.A., and we’re encouraged by the continuing conversations around how we can make our communities more resilient against our changing climate.”
In a sign of progress, the $1 trillion, bipartisan infrastructure bill, signed by U.S. President Joe Biden in 2021, included $50 billion for climate resilience and weatherization projects, and $65 billion in investments for clean energy and green grid initiatives.
Other 3M innovations that can help make cities cooler and greener include:
- • 3M™ Natural Pozzolans: These can be used as a partial cement replacement to help lower the C02 emissions of concrete production.
- • 3M™ Nanostructured Supported Iridium Catalyst Powder: This under-development catalyst technology could be used to increase the efficiency of, and cut the cost of, green hydrogen – a sustainable fuel that does not release carbon emissions during the production process.
- • 3M™ Passive Radiative Cooling Film: This film reflects solar energy to provide 24/7 passive thermal management.
“A range of cooling solutions are already available at 3M, and we’re eager to partner on products and solutions that can address the many issues that communities are facing due to extreme heat,” said Niezgocki.