With two-thirds of the world’s population predicted to live in urban areas by 2050 and, knowing cities already account for roughly three-quarters of greenhouse gas emissions, it’s little wonder people are looking to cities to help mitigate the effects of climate change. In Part 1 of this article, I provided some background on the importance of cities in helping save the planet from climate change caused by human activity. In Part 2, I want to look a little more closely at some of the initiatives currently underway as well as recommendations about what more can and should be done. Ben Hawes, Associate Director at the Connected Places Catapult, bluntly states, “It’s hard to make a substantial change to how a city runs.” He adds, “Successful cities are generally already going through continual change. Failing cities generally aren’t managing to change to meet new conditions. In either case, it’s no easy task to add a major course correction. The same living, ‘coral reef’ ecosystem that is a thriving city can also become a knot of misaligned incentives, agency problems and unintended consequences.” He could have also added that changing how a city functions can be costly and few cities are flush with cash. Nevertheless, Hawes believes, “Save the city, save the world.” He might just as well have stated, “Save the city. Save us from ourselves.” Kate Marvel (@DrKateMarvel), a climate scientist at Columbia University, puts it this way, “The scariest thing about climate change is what it will make us do to each other.”
Smart cities start with a good design
City policymakers appear to understand the significance of their actions. Hundreds of cities have signed on to meet international goals to mitigate the effects of climate change. At the same time, policymakers also seem to understand climate change is likely to affect their cities in a negative way and are undertaking efforts to adapt to these changes. Jeffrey Raven (@jeffraven) an associate professor and the director of the Graduate Program in Urban and Regional Design at New York Institute of Technology, writes, “Policymakers see mitigation and adaptation as mutually exclusive. That’s a mistake. Sometimes, even successful efforts to mitigate climate change can lead to more local warming. And climate change could render the most forward-thinking adaptation efforts obsolete. To ensure that cities remain livable, mayors and urban leaders — together with urban designers — must simultaneously cut emissions and help residents adapt to a warming planet. Consider the push to boost the number of energy-efficient buildings. Such efforts are only successful if planners also keep cityscapes cool, as efficiency doesn’t always reduce energy use.”
In other words, city planners and policymakers need to take a holistic approach to making cities smarter in the years ahead. Raven concludes, “Cities that embrace ‘adaptive mitigation’ — those that reduce CO2 emissions while also helping their residents adapt to a changing climate — are better positioned to remain livable.” Hawes believes artificial intelligence (AI) can help city planners take a holistic approach. He explains, “Artificial intelligence is being developed across many areas of resource management and business planning, (just) in time to offer us help with the challenges of climate change. AI could make it easier to use energy and other resources more efficiently, and give new insights into large-scale urban problems and interdependencies.” He cautions, however, “This doesn’t mean — as some reports seem to suggest — that we can just throw AI at city economies, and green growth will flourish. It’s not going to be that easy. Targeted machine learning applications can substantially improve the handling of resources in specific contexts, but these are often not easily repurposed and scaled from one context to another.”
Jason Plautz (@Jason_Plautz) reports ,”A recent survey from the U.S. Conference of Mayors found that 60% of cities had adopted or expanded a climate policy in the prior 12 months, including many focused on renewable energy. In the absence of U.S. federal leadership, many cities have taken up the goals of the Paris agreement through the ‘We Are Still In‘ coalition. However, [a new guide from the United Nations (UN) Intergovernmental Panel on Climate Change (IPCC)] recognizes that funding can be a challenge, since taxes often flow to the top levels of government and current capital investments can’t support the necessary changes to urban infrastructure.” Just because it will be challenging, doesn’t mean we don’t have to try.
Smart cities and the urban heat island effect
Let’s look at just one of the challenges large cities face: the urban heat island effect. Rutgers University researchers explain, “In cities with 1 million or more people, average air temperatures can be 1.8 to 5.4 degrees Fahrenheit higher than in less densely populated areas. The difference can be up to 22 degrees at night.” Raven adds, “Dense urban areas tend to contain lots of heat-absorbing materials like asphalt. That can make them much hotter than their surroundings. This ‘heat island effect’ can leave city residents with little choice but to crank up their air conditioning — and consequently, increase emissions.” Rutgers’ engineers believe they have a partial solution to asphalt problem. They write, “Special permeable concrete pavement can help reduce the ‘urban heat island effect’ that causes cities to sizzle in the summer. … Permeable pavement contains large connected pores, allowing water to drain through and reducing pavement temperature. Water in pores will also evaporate, reducing pavement surface temperature. Moreover, permeable concrete pavement does a better job reflecting heat than asphalt pavement. The study found that permeable concrete pavement gives off slightly more heat on sunny days compared with conventional concrete pavement, but 25 to 30 percent less heat on days after rainfall. The engineers improved the design of permeable concrete with high thermal conductivity — meaning it can transfer heat more quickly to the ground — further reducing heat output by 2.5 percent to 5.2 percent.”
Of course, paving roads is not cheap. Raven notes some efforts to combat the heat island effect don’t need to be costly. He writes, “Smart cities intersperse green spaces and parks throughout building-heavy, highly populated areas. This vegetation absorbs harmful air pollutants. One tree can absorb as much as 26 pounds of CO2 in a year. The shade provided by trees can also help lower temperatures. Further, water vapor evaporating from plant surfaces cools the surrounding air. Such climate strategies don’t require expensive technologies or sustained political will. Yet they’re often overlooked when city leaders focus exclusively on carbon emissions or adaptation.” There are, of course, a lot of things cities need to do to implement adaptive mitigation and make cities more livable, even while they make them more sustainable.
All stakeholders (e.g., policymakers, scientists, developers, and citizens) need to buy in to efforts to make cities change-agents for good. Hawes notes, “Cities cannot apply AI to climate change reduction and mitigation without transforming processes, capabilities and decision-making in city agencies, and without local buy-in to make and deliver different and difficult decisions affecting local economies.” They haven’t much time to make that buy-in. Katie Pyzyk (@_PyintheSky) reports, “77% of the world’s cities will experience a striking change in climate conditions by 2050.” Raven concludes, “Two-thirds of the world’s population will live in cities by 2050. Most of the urban spaces these individuals will inhabit have yet to be designed. So the design decisions we make today will have extraordinary consequences on our climate for generations. But they’ll also affect the culture of the planet’s growing urban population. As mayors and urban leaders plan for a warming planet, they shouldn’t forget that, above all, cities are for living.”
 Ben Hawes, “AI, cities and climate change,” Smart Cities World, 8 August 2019.
 Kate Marvel, “Lost Cities and Climate Change,” Scientific American, 29 July 2019.
 Jeffrey Raven, “To curb climate change, cities need proper design,” White Mountain Independent, 26 December 2017.
 Jason Plautz, “UN report: Cities are ‘key implementers’ of climate policies,” Smart Cities Dive, 11 December 2018.
 Rutgers University, “How roads can help cool sizzling cities,” EurekAlert!, 1 August 2019.
 Katie Pyzyk, “77% of global cities will experience ‘striking shift’ in climate by 2050,” Smart Cities Dive, 12 July 2019.