Urban Sustainability: An introduction

In 2016 Macalester included "sustainable urban environment" as part of the college-wide sustainability plan. In its most distilled state, sustainable urban environments guarantee equality, health, opportunity, support, and safety for all its inhabitants (human and non-human). In this way, creating sustainable cities reaches far beyond direct environmental benefits through options like investments in renewable energy sources and bike-to-work days. If applied and pursued properly, urban sustainability can be used as a framework to forge equitable social, environmental, and economic futures.

Sustainability is the intersection between three interdependent subcategories: people, planet, and profit. In order for something to be sustainable, all three of these branches need to be accounted for and satisfied. A sustainable city creates the highest possible quality of life for its inhabitants; this is a measure of its social performance. The same city also needs to focus on its "green" factors (energy, pollution, and emissions); this impacts its environmental footprint. Lastly, it needs to exhibit a strong but healthy business environment and economy. So, how do we measure these three factors contributing to the sustainability of a city? What do we use to quantify and measure a city's people, planet, and profit?

In 2013, The United Nations released a World Economic and Social Survey outlining the factors contributing to a city's sustainability. This article describes urban sustainability using the following four points.

1. A sustainable city fosters social development. This includes education, health, food, and nutrition, green infrastructure, water and sanitation, green public transit, green energy access, recreation areas, and community support. 
2. A sustainable city has a strong, green, growing economy. This means investments in "green" productive growth, creation of decent employment, production and distribution of renewable energy, and technological innovation. 
3. A sustainable city practices environmental management. This includes forest and soil management, waste and recycling management, energy efficiency, water management, air quality conservation, and adaptation to a mitigation of climate change. 
4. Finally, a sustainable city is governed well. Solid urban governance values planning and decentralization; negates social inequities; supports strong civil and political rights; maintains local, national, regional, and global links (United Nations World Economic and Social Survey 2013, page 62). 

Expanding on the UN description, Arcadis adds quantitative factors to gauge and calibrate a city's sustainability. The factors contributing to this definition of a sustainable urban environment include the following: 

People

• Health: life expectancy and obesity
• Education: literacy and universities 
• Income inequality 
• Work-life balance 
• The dependency ratio (number of dependents, 0-14 and 65+ to the total population, aged 15-64) 
• Crime 
• Housing and living costs 

Planet 

• Energy consumption and renewable energy share 
• Green space within cities 
• Recycling and composting rates 
• Greenhouse gas emissions 
• Natural catastrophe risk 
• Drinking water 
• Sanitation 
• Air pollution 

Profit 

• Measures of transport infrastructure (rail, air, and traffic congestion) 
• Ease of doing business
• Tourism 
• GDP per capita 
• A city's importance in global economic networks 
• Connectivity in terms of mobile and broadband access
• Employment rates 

A sustainable urban environment is something that engages with each and every stakeholder it houses. There is no denying that defining and thoroughly describing urban sustainability is important, but the truly monumental task is applying and understanding how this idea actually exists on the ground. By collaborating with and learning from the thousands of other cities around the world, sustainable urban environmental practices will continue to grow in number.