More than half the people on Earth live in cities. I live in one, and odds are you do, too.
If I ask you to think of a beautiful natural landscape, you will most likely imagine some wild, isolated place far from your own neighborhood. Many city dwellers may think of themselves as living completely separate from nature, but in fact our urban lives depend on it.
Although cities only cover 2% of the Earth’s surface, they use up to 75% of its natural resources, most of which come from outside the city limits. In other words, modern cities rely on the ecosystem services — including food and freshwater provision, air quality regulation, building materials and many other benefits — of nearby natural areas to keep them running.
How sustainable is this? Not very — and in the near future, it will probably be even less so.
By 2030, land covered by cities will have expanded by 200%, while the global urban population will have grown 70%. By 2050, the urban population will have doubled.
There is a considerable overlap between expanding urban areas and biodiversity hotspots — 35 global regions that are home to a disproportionate percentage of the planet’s species. Under business as usual, continued city growth would mean further loss of natural habitats and consequent deterioration of biodiversity and associated ecosystem services.
The movement toward more sustainable cities needs to move fast from concept to reality for the benefit of people everywhere.
Fortunately, there are many people thinking about such issues. Alternatives and innovations are beginning to emerge — from habitat restoration to urban agriculture, from waste management to wise energy use, from climate security to prevention of natural disasters.
At CI, we believe that many of these alternatives need to be incorporated into policy decisions, replicated in different locations and exchanged between different cities. We are now facilitating a technical exchange between the Latin American cities of Bogotá, Mexico City and Rio de Janeiro — three cities that face similar challenges and are pursuing creative solutions to ensure sustainable water supplies for their large populations.
Rio is my hometown. Despite all the problems we have in this city, whenever I have to think of a beautiful nature scene I still think of the Rio I saw in my childhood rather than a wild landscape far away.
There is one painting that takes me back to those shining days. It is called “Rio de Janeiro, gosto de você, gosto dessa gente feliz” (or “Rio de Janeiro, I like you, I like these happy people”) by local artist Lia Mittarakis (1934-1998). For some reason, this painting remains my image of a sustainable city: people and buildings surrounded by enough green and blue to allow them to live happily.
Over the coming months, Human Nature’s “Urban Jungle” blog series will explore the inextricable connections between intact ecosystems and thriving cities — and examine some of the efforts underway to make urban life more sustainable.
Fabio Scarano is the senior vice president of CI’s Americas field division. Read the next post in our “Urban Jungle” series — and to learn more about the role of nature in cities, check out informative readings on the topic here and here.