The UN Environment Program (UNEP) has published detailed guidance to help the world’s cities address warming, which is occurring at twice the global average rate in urban areas.
Beating the Heat: A Sustainable Cooling Handbook for Cities, states that by the end of this century, many cities could warm as much as 4 °C if GHG emissions continue at high levels. Even at 1.5°C of warming, 2.3 billion people could be vulnerable to severe heat waves.
Launched at the ongoing UN Climate Conference (COP26) by the Cool Coation, UNEP, RMI, the Global Convenant of Mayors for Climate & Enegy, GCoM, Mission Innovation and the Clean Cooling Collaborative, the new guide offers planners an encyclopedia of proven options to help cool cities.
UNEP executive director, Inger Andersen, said to keep global temperatures from rising more than 1.5°C, net-zero needs to be in place by mid-century.
“Sustainable and equitable urban cooling must be a part of cities’ efforts to reach net-zero energy targets,” Andersen said.
In outlining the problem, the Sustainable Cooling Handbook for Cities describes how cities are warming quickly due to the “heat island effect”, caused by a combination of diminished green cover, the thermal properties of the materials commonly used in urban surfaces, and waste heat from human activities.
The handbook notes that::
Demand for space cooling is increasing. The energy requirement for space cooling is predicted to triple from 2016 to 2050 as millions of households in developing countries acquire air conditioners in the coming decades.
Impacts of urban heat are not evenly distributed. Cooler cities, homes and streets are key to ensure climate justice. Lower-income districts and communities are usually the most vulnerable to heat, placing the negative impacts of excess warming disproportionately on those least likely to be able to afford or access thermal comfort. We need to transition to more equitable and sustainable ways of cooling our cities and make them liveable for all.
The benefits of sustainable urban cooling are far reaching, including improved health and productivity, reduced power energy requirements, lower emissions, and economic benefits.
Cooling strategies can be optimized to work together efficiently. The report calls for a whole-system approach – that is, reduce heat at urban scale, reduce cooling needs in buildings and serve cooling needs in buildings efficiently – to benefit from integrative effects.
City officials working to make their cities cooler and more liveable are faced with a wide range of approaches – the challenge is where to start, according to RMI CEO, Jules Kortenhorst.
“Based on systems-level thinking, this handbook includes actionable guidance to help cities make progress towards sustainable and equitable urban cooling, while also cutting emissions and increasing city resilience,” Kortenhorst said.