Urban planning and urban design

Urban planning and urban design have a critical role to play in the global response to climate change. Actions that simultaneously reduce greenhouse gas (GHG) emissions and build resilience to climate risks should be prioritized at all urban scales – metropolitan region, city, district/neighborhood, block, and building. This needs to be done in ways that are responsive to and appropriate for local conditions. Major Findings Urban planners and urban designers have a portfolio of cli- mate change strategies that guide decisions on urban form and function: • Urban waste heat and GHG emissions from infrastructure – including buildings, transportation, and industry – can be reduced through improvements in the efficiency of urban systems. • Modifying the form and layout of buildings and urban districts can provide cooling and ventilation that reduces energy use and allow citizens to cope with higher temperatures and more intense runoff. • Selecting low heat capacity construction materials and reflective coatings can improve building performance by managing heat exchange at the surface. • Increasing the vegetative cover in a city can simultaneously lower outdoor temperatures, building cooling demand, run- off, and pollution, while sequestering carbon. Key Messages Integrated climate change mitigation and adaptation strategies should form a core element in urban planning and urban design, taking into account local conditions. This is because decisions on urban form have long-term (>50 years) consequences and thus strongly affect a city’s capacity to reduce GHG emissions and to respond to climate hazards over time. Investing in mitigation strategies that yield concurrent adaptation benefits should be prioritized in order to achieve the transformations necessary to respond effectively to climate change. Consideration needs to be given to how regional decisions may affect neighborhoods or individual parcels and vice versa, and tools are needed that assess conditions in the urban environment at city block and/or neighborhood scales. There is a growing consensus around integrating urban planning and urban design, climate science, and policy to bring about desirable microclimates within compact, pedestrian- friendly built environments that address both mitigation and adaptation. Urban planning and urban design should incorporate long- range mitigation and adaptation strategies for climate change that reach across physical scales, jurisdictions, and electoral timeframes. These activities need to deliver a high quality of life for urban citizens as the key performance outcome, as well as climate change benefits.