Cool Cities

As one of the hottest summers in Northern European memory is coming to an end it is more urgent than ever to reflect on what we can do to slow down and adapt to the new climate reality. Long term solutions should be pursued along with short-term fixes. And they should be global as well as local. In addition to contributing to the global slowdown, local solutions in cities will be crucial for saving human lives affected by the urban heat island effect – some 650 American lives are lost each year as a result of it.

Just down the street from where I am camping out for the summer, Washington DC is piloting new ways of expanding and protecting its urban landscape. Green infrastructure such as street trees, permeable pavements and rain gardens (bioretention) are increasingly built into city planning efforts. These natural mechanisms capture rainfall, cool buildings and pavements, and create natural pathways for wildlife. Another marvel of green engineering is DC Water’s expansion of its sewage and stormwater runoff capacity. Rather than building a traditional system of grey infrastructure, they had the foresight to incorporate green elements such as permeable pavements and vegetation to collect the excess rainwater. DC Water’s green infrastructure project is particularly dear to my heart as I was involved in early discussions of the $350 million green bond to finance the expansion. An even cooler $25 million environmental impact bond (pay-for-success) was issued in 2016. This is forward thinking blending innovative projects with innovative finance. We need more of both.