Frequently Asked Questions — Why Smart Surfaces?
What are smart surfaces?
“Smart surfaces” is a new term coined by Greg Kats and the Smart Surfaces Coalition, referring to cool roofs, green roofs, solar PV, porous pavements, urban trees, and combined surfaces. The term acts as a useful conceptual umbrella and allows for a diverse range of climate change mitigation strategies to be considered together as a unified solution.
Previous mitigation and adaptation strategies have focused on one smart surface at a time — whether it be implementing solar roofs or planting urban trees. This piecemeal approach is inefficient and inadequate, because city agencies have neither the expertise nor authority to consider broader benefits such as health or urban heat, and do not consider surface decisions outside their traditional jurisdiction. Considering smart surfaces together and at a city-wide level allows both a far more efficient way to design cites and gives cities the capacity to consider a far more complete set of costs and benefits. In turn, cities can, for the first time, make surface decisions that reflect their full interests, including temperature, risk, and livability.
What are the policy benefits of smart surfaces?
By thinking of smart surfaces as a single strategy, policy-makers can comprehensively evaluate a city’s status quo surfaces and decide on the best combination of smart surface replacements to achieve environmental objectives, including reductions in heat, air pollution, and flooding, to name a few. The smart surfaces approach also allows for the possibility of integrated solutions, such as solar PV on top of cool and green roofs, which can compound cooling benefits.
“Smart surfaces” provides a logical and essential conceptual grouping around managing sun and rain. Pavements allow water drainage, trees provide shade, and roofs protect houses from the elements. We can harness the power of city surfaces, which are already essential to livability, to manage sun and rain more effectively, while also achieving immense cooling, healthy, equity, and livability benefits. When taken together, “smart surfaces” becomes a powerful mitigation and adaptation solution that city legislators can embrace.
What are the financial benefits of adopting smart surfaces?
The Smart Surfaces Coalition has calculated that the urban adoption of smart surfaces throughout the United States would have a net present value of $700 billion and create over 250,000 new jobs by 2050. Take Washington, D.C., as an example. The Coalition’s cost-benefit analysis research has concluded that if the capital spends $838 million on smart surfaces now, it could see $2.6 billion dollars in benefits by 2050 — a net present value of $1.8 billion. And D.C. is no outlier — the average benefit-cost ratio for most cities falls between 2:1 and 4:1.
One important sector of benefits includes greater energy efficiency. D.C. can expect $348 million in energy benefits over 40 years if it invests in the adoption of smart surfaces technologies. Since the combination of traditional dark surfaces and increasing global temperatures results in stifling summer heat, cities can expect an increase in energy bills over the coming decades if they continue to use status-quo surfaces.
Smart Surfaces Coalition intentionally advances a cost-benefit approach to considering cooling solutions. Whereas moral arguments may be easily dismissed, quantified financial benefits are hard to ignore. The Coalition’s cost-benefit analytic engine allows cities to quantify future benefits like never before, presenting a win-win solution that policy-makers cannot afford to overlook.
What are the equity implications of smart surfaces?
Average city temperatures are rising around the globe, but within city boundaries, warming effects are far from equally felt. Cooling cities is not just an environmental objective — it is inextricably tied to social equity. A New York Times article reported on a study (conducted by Vivek Shandas of Portland State University, a Coalition partner) which found a striking correlation between historically redlined neighborhoods and hotter temperatures. As a result, low-income neighborhoods, often predominantly home to minorities, tend to have less tree cover and more paved surfaces, raising temperatures up to 15 degrees hotter than wealthier neighborhoods. Recent research from Harvard University has also shown that the impact of energy costs is unequal and affects urban communities disproportionately, as low-income tenants spend significantly more on energy bills relative to higher-income tenants.
As climate change intensifies, low-income populations face dire health consequences. Ambient air pollution leads to increased risk of lung cancer and heart disease, while hotter temperatures discourage outdoor exercise and enable an inactive lifestyle, prompting increased risk of obesity and diabetes. Other health impacts include direct harms from climate change-altered weather, mental health effects, and the increased spread of diseases, according to a report from the Medical Society Consortium on Climate and Health. And these adverse effects will only worsen as climate change continues its course.
Luckily, the benefits of smart surface adoption accrue most dramatically in low-income areas — partially correcting these unequal heat impacts. City investment in smart surfaces would increase tree cover, reduce air pollution, and decrease heat radiance, cooling low-income areas by up to 10℉ by 2050. This dramatic reduction would immediately enhance city livability and facilitate health benefits everywhere, but most visibly in low-income areas.
Why is SSC focused on cities?
According to a 2018 UN report, 55% of the world’s population lives in urban areas—a proportion that will likely increase to around 70% by 2050. That number is even higher in the United States — nearly 80%, according to the 2016 Census.
Why does this matter? Unsurprisingly, urban areas consume significantly more energy than rural areas. A 2014 IPCC report estimates that urban areas use between ⅔ and ¾ of the global energy supply, and account for about ¾ of global carbon emissions. Even more worryingly, high-emitting cities can easily fall into vicious cycles: rising temperatures can lead to more dependence on air conditioners, which leads to yet more emissions.
Cities are also much hotter than rural areas due to the so-called “urban heat island effect.” Cities are too often covered by dark, impervious surfaces, like tar roofs and black pavements — an inhospitable landscape that does little to reflect the vibrant life contained therein. These surfaces tend to absorb more heat than surrounding rural landscapes, creating “islands” of higher temperatures.
The good news is that cities also provide a major opportunity to affect large changes cost-effectively. Replacing dark, impervious surfaces with smart surfaces — like solar PV, urban trees, and green roofs — is an untapped opportunity to mitigate carbon emissions and enhance city livability. Furthermore, it’s financially prudent to make the switch, as the long-term benefits unequivocally outweigh the short-term costs, sometimes by a factor of 4:1, not to mention the thousands of new infrastructure jobs that would be created.
What is the benefit of using a coalition to advance this strategy?
Smart Surfaces recognizes that climate change is a multidimensional and intersectional issue and should be addressed as such. Smart Surfaces is a partnership of 40+ key organizations across a variety of sectors — including the National League of Cities, Habitat for Humanity, American Public Health Association, Carnegie Mellon University, and American Institute of Architects (see all partners). The Coalition structure galvanizes these diverse groups around a common mission statement, advancing a more comprehensive, nuanced, and compelling case to policy-makers.