Though urban agriculture (UA), defined here as growing of crops in cities, is increasing in popularity and importance globally, little is known about the aggregate benefits of such natural capital in built‐up areas. Here, we introduce a quantitative framework to assess global aggregate ecosystem services from existing vegetation in cities and an intensive UA adoption scenario based on data‐driven estimates of urban morphology and vacant land. We analyzed global population, urban, meteorological, terrain, and Food and Agriculture Organization (FAO) datasets in Google Earth Engine to derive global scale estimates, aggregated by country, of services provided by UA. We estimate the value of four ecosystem services provided by existing vegetation in urban areas to be on the order of $33 billion annually. We project potential annual food production of 100–180 million tonnes, energy savings ranging from 14 to 15 billion kilowatt hours, nitrogen sequestration between 100,000 and 170,000 tonnes, and avoided storm water runoff between 45 and 57 billion cubic meters annually. In addition, we estimate that food production, nitrogen fixation, energy savings, pollination, climate regulation, soil formation and biological control of pests could be worth as much as $80–160 billion annually in a scenario of intense UA implementation. Our results demonstrate significant country‐to‐country variability in UA‐derived ecosystem services and reduction of food insecurity. These estimates represent the first effort to consistently quantify these incentives globally, and highlight the relative spatial importance of built environments to act as change agents that alleviate mounting concerns associated with global environmental change and unsustainable development.

The United States (US) and the European Union (EU) are federal systems in which the responsibility for environmental policy-making is divided or shared between the central government and the (member) states. The attribution of decision-making power has important policy implications. This chapter compares the role of central and local authorities in the US and the EU in formulating environmental regulations in three areas: automotive emissions for health related (criteria) pollutants, packaging waste, and global climate change. Automotive emissions are relatively centralised in both political systems. In the cases of packaging waste and global climate change, regulatory policy-making is shared in the EU, but is primarily the responsibility of local governments in the US. Thus, in some important areas, regulatory policy-making is more centralised in the EU. The most important role local governments play in the regulatory process is to help diffuse stringent local standards through more centralised regulations, a dynamic which has become recently become more important in the EU than in the US.

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With over half of the world's population living in cities, there is mounting evidence indicating that investments in urban sustainability can deliver high returns on socioeconomic and environmental fronts. Current scholarship on urban agriculture (UA) reports a wide range of benefits which have been shown to vary with the scale and type of benefit examined. Notably, most city-scale studies do not align benefits of UA with locally meaningful goals. We fill this gap by conducting a city-scale analysis for Phoenix, the fifth largest city in the USA by population, and evaluate these benefits based on their ability to contribute to select desired outcomes specified in Phoenix's 2050 Sustainability Goals: the elimination of food deserts, provision of green open space, and energy and CO 2 emissions savings from buildings. We consider three types of surfaces for UA deployment-undeveloped vacant lots, flat rooftops, and building façades-and find that the existing building stock provides 71% of available UA space in the study area. The estimated total food supply from UA is 183 000 tons per year, providing local produce in all existing food deserts of Phoenix, and meeting 90% of current annual consumption of fresh produce based on national per capita consumption patterns. UA would also add green open space and reduce by 60% the number of block groups underserved by public parks. Rooftop deployment of UA could reduce energy use in buildings and has the potential to displace more than 50 000 tons of CO 2 per year. Our work highlights the importance of combining a datadriven framework with local information to address place-based sustainability goals and can be used as a template for city-scale evaluations of UA in alternate settings.

The United States (US) and the European Union (EU) are federal systems in which the responsibility for environmental policy-making is divided or shared between the central government and the (member) states. The attribution of decision-making power has important policy implications. This chapter compares the role of central and local authorities in the US and the EU in formulating environmental regulations in three areas: automotive emissions for health related (criteria) pollutants, packaging waste, and global climate change. Automotive emissions are relatively centralised in both political systems. In the cases of packaging waste and global climate change, regulatory policy-making is shared in the EU, but is primarily the responsibility of local governments in the US. Thus, in some important areas, regulatory policy-making is more centralised in the EU. The most important role local governments play in the regulatory process is to help diffuse stringent local standards through more centralised regulations, a dynamic which has become recently become more important in the EU than in the US.