Although there are people who deny human activity affects climate change, most scientists believe the facts demonstrate human activities do make a difference. Kate Marvel (@DrKateMarvel), a climate scientist at Columbia University, writes, “Some people say ‘the climate has changed before,’ as though that should be reassuring. It’s not.” Since more people now live in urban areas, the importance of cities in helping mitigate climate change has never been greater. The United Nations estimates cities will be home to an estimated two-thirds of the world’s population by 2050, and cities already account for roughly three-quarters of greenhouse gas emissions. Jason Plautz (@Jason_Plautz) reports a new guide from the United Nations (UN) Intergovernmental Panel on Climate Change (IPCC), concludes, “Cities are ‘key implementers’ of policies that will help avert the worst consequences of climate change. … The guide — released by The Global Covenant of Mayors and C40 Cities — says that without action from cities, ‘there will be no limiting global warming to 1.5 degrees Celsius.’ … In order to limit warming below the 1.5 degree threshold, emissions from buildings in 2050 will need to be between 80% and 90% lower than today, while energy use from transportation will need to be about 30% lower than today’s levels. Measures like building codes, energy efficiency measures and public transit are among the urban strategies that can meet those goals, the report recommends.”
Past as prologue
Marvel thinks it wise to look back to see how natural climate change has affected humans throughout history. She writes, “Many historical events have happened against a backdrop of natural climate change. Drought in the steppes east of Hungary pushed marauding Huns west and toppled the Roman empire. Volcanic activity suppressed crop yields in pre-revolutionary France, leading hungry, desperate peasants to take drastic action.” She goes on to note climate change isn’t the only factor driving human history. “We humans,” she writes, “are not passively dragged along by temperatures and rainfall patterns.” Climate change, however, almost always exacerbates the human condition. She explains, “The adversity brought by climate change caused societies to break apart, magnified pre-existing divisions, and made desperate people easy prey for dangerous people.” As noted above, she finds cold comfort in knowing the climate has changed before. “I have never understood how anyone could find this comforting,” she writes. “The natural climate changes that have shaped human history have almost always been smaller and more regionally contained than the large-scale human-caused change we are currently experiencing. And even these changes have provoked suffering, scapegoating, and the collapse of civilizations.”
What lies ahead, reports Katie Pyzyk (@_PyintheSky), is the warming and drying of cities across the globe. She draws those conclusions from a study published in the scientific journal PLOS One. The study found, “All cities’ climates in both the Northern and Southern hemispheres generally are predicted to shift toward the conditions in warmer, low-latitude (equatorial) regions, while cities in the tropics will experience pronounced shifts to drier conditions. The report warns that 22% of cities will experience conditions not currently found in any city in the world. This scenario would be most pronounced in the tropics — 64% of the cities that will experience these novel climate conditions are in the tropics — including Jakarta, Indonesia; Kuala Lumpur, Malaysia; and Singapore.” Marvel worries about such changes. She explains, “I am often asked what frightens me most about climate change, whether I lie awake at night thinking about ocean hypoxia or arctic permafrost or other feedback processes that could turn a bad thing into a catastrophe. I am scared of the physical changes that await us on a warming planet, but the most important feedback process is the least well understood. The scariest thing about climate change is what it will make us do to each other.”
Cities can help minimize climate change
Study after study have concluded, per capita, cities use resources better than suburban or rural areas. Smart initiatives can help cities use resources even more efficiently. Even so, smart cities need smart residents. Justin Fox (@foxjust) explains, “Dense, transit-oriented development is more environmentally friendly than suburban sprawl. But city dwellers shouldn’t get too smug about that. Just because an urban apartment uses fewer resources than a McMansion doesn’t always mean that its inhabitants use fewer resources than suburbanites.” He adds, “Existing U.S. research that tracks direct energy use for heating, electricity, and local transportation — and finds cities to be much greener per-capita than suburbs — definitely misses out on some of the ways that affluent urbanites can have big environmental footprints even if they take the subway to work.” All of these considerations must be taken into account if smart cities are going to help mitigate the effects of climate change. Fox notes, “Getting food into the city from farms, and other goods from warehouses, surely takes longer (and consumes more energy) [than getting them to suburbs]. Big cities are great, but they’re not the solution to all the world’s environmental challenges.” Maybe not, but Paris Mayor Anne Hidalgo, insists, “Cities are ready to lead on the transformations necessary to secure the future that we want, the future we can trust.”
Gary Grant (@ecoschemes), Director of the Green Infrastructure Consultancy, correctly observes, “As yet, there are no smart cities. … So far, we have had initiatives, policies, strategies, and some projects, but no examples of cities where it all comes together in a genuinely city-wide way.” He continues, “The smart city agenda has a strong green emphasis regarding reducing the production of carbon dioxide, through the operation of smart electricity supply grids, increasing efficiency and harnessing low-carbon energy supplies.” Nevertheless, he asserts, city planners can do more. He concludes, “It is important that smart cities are as much about nature, health, and well-being as traffic flows, crime detection, and evermore efficient provision of utilities. Making the city more permeable to both wildlife and people is a process that could be informed by bringing sensors that monitor the movement of wildlife. Climate change adaptation using natural interventions is already on the agenda of many cities. However, the efficacy of green infrastructure types and combinations in providing cooling and absorbing rainwater will be significantly improved through both detailed and wide-scale real-time measurement of temperature, humidity, evapotranspiration rate and flows. Combining this data with maps of hardship and deficiency will help cities to become smarter in the way they prioritize greening efforts.” In Part 2 of this article, I will examine some of the initiatives cities are undertaking to help mitigate climate change.
 Kate Marvel, “Lost Cities and Climate Change,” Scientific American, 29 July 2019.
 Jason Plautz, “UN report: Cities are ‘key implementers’ of climate policies,” Smart Cities Dive, 11 December 2018.
 Katie Pyzyk, “77% of global cities will experience ‘striking shift’ in climate by 2050,” Smart Cities Dive, 12 July 2019.
 Justin Fox, “Cities Are Good for the Environment, But Many City Dwellers Aren’t,” Bloomberg, 23 July 2019.
 Plautz, op. cit.
 Gary Grant, “Can Smart Cities be Smart Green Cities? We’ll See,” The Nature of Cities, 18 December 2017.