10.1 Introduction to sustainability and cities

Usually when we think of protecting the environment, we think about wilderness, places ‘out in nature’ where animals live without direct human influence. When we think of cities, we think of buildings and streets and cars, the opposite of nature. So why are cities an essential part of environmental sustainability? Here are three big reasons.

Life in cities

The way we set up our cities determines how healthy and safe the urban environment is for humans and other species to live in. More than half of the global population lives in cities, and all those people deserve good, healthy lives. Clean air, clean water, and access to natural spaces are essential to our health. Urban development and climate change threaten those necessities, causing more direct harm to certain groups of people than others. The people whose lives are affected by those threats deserve a say in how their cities develop and how the world works to address climate change. In addition to humans, thousands of plant and animal species are found in urban and suburban areas – some cities are even considered biodiversity hotspots and critical conservation areas. A lot of people who care about protecting the rest of nature live in cities, and they have the opportunity to make a huge difference right where they are.

Cities’ local impact

Urbanization has a huge effect on the land where it happens. Replacing fields and forests with pavement and human structures destroys habitat, and when humans in a city use resources and produce waste, it can pollute the surrounding air and water. However, not all urbanization has the same level of impact on its surroundings. There are more and less responsible ways to put together cities, and because increased urbanization is inevitable (the human population is still growing, and many people are moving to cities), it’s critical that we do it responsibly.

Cities’ global impact

People’s lifestyles, like what they eat, what they buy, how they get around, and how much energy they use, determine the environmental impact they have. As of 2020, the 55% of the world’s population that lived in cities consumed two thirds of the world’s energy and caused 70% of CO₂ emissions,^[1] meaning the average city-dweller had a larger environmental impact than the average person in the world. Cities can be set up to facilitate low-impact lifestyles, and many of the choices that decrease energy use and emissions also improve the health of city residents.