ABSTRACT

Globally, more than 50% of the world’s population lives in urban areas, with the percentage forecasted to increase to 66% by 2050 (UN-DESA 2014). Although urban areas constitute less than 3% of the Earth’s terrestrial surface, they have a signicant ecological footprint, accounting for an estimated three-fourths of global carbon emissions and 60% of residential water use (Grimm et al. 2008). They are also major local and regional sources of airborne pollutants and waste products (Grimm et al. 2008) and can have a strong impact on local environmental conditions. For example, elevated air temperatures in urban areas, known as the urban heat island effect (Voogt and Oke 2003; Weng et al. 2004; Weng 2009), can negatively impact human health (Patz et al. 2005) and can modify urban phenology by extending the growth season in cold environments (Zhang et al. 2004). Urban form, such as the distribution of urban green space, impacts urban climate (cooling by tree shading and advection; Middel et al. 2014), whereas road structure impacts transportation ows and associated emissions (Hoek et al. 2008). Of particular interest is the relative proportion of green cover and impervious surfaces, which impacts urban air

CONTENTS

Introduction ......................................................................................................... 247 SMA in the Urban Environment ....................................................................... 252 Case Study from Santa Barbara.........................................................................256